Researcher Database

Researcher Profile and Settings


Affiliation (Master)

  • Faculty of Information Science and Technology Electronics for Informatics Advanced Electronics

Affiliation (Master)

  • Faculty of Information Science and Technology Electronics for Informatics Advanced Electronics


Profile and Settings

Profile and Settings

  • Name (Japanese)

  • Name (Kana)

  • Name


Alternate Names


Research Interests

  • ブリュースター角顕微鏡   水面上単分子膜   光ピンセット   テクスチャー   配向弾性   分子配向   ずり応力場   ピンセット   コンダクタンスピーク   ディスクリネーション   ドメイン   分子再配向   線張力   マランゴニー不安定性   流動配向   非平行成長   非平衡成長ドメイン   光ビンセット   局所加熱   固相膜   トンネル分光   ナロ-ギャップ半導体   ずり流動   

Research Areas

  • Nanotechnology/Materials / Thin-film surfaces and interfaces
  • Nanotechnology/Materials / Crystal engineering
  • Nanotechnology/Materials / Applied materials
  • Nanotechnology/Materials / Applied physics - general

Research Experience

  • 2007 北海道大学 大学院・情報科学研究科 助教

Published Papers

  • E. Hatta, K. Nihei
    Physical Chemistry Chemical Physics 23 (39) 22543 - 22550 1463-9076 2021/09 [Refereed]
    A statistical mechanical deconvolution procedure for the measured surface pressure–area isotherms has been presented to obtain nanocluster size distributions in the LE–LC phase coexistence region of DMPC monolayers at the air–water interface.
  • Emergence of a linear slope region of the isotherm in the first-order liquid-expanded-liquid-condensed phase transition in Langmuir monolayers
    Eiji Hatta, Ko Nihei
    PHYSICAL REVIEW E 100 (2) 022801-1 - 022801-10 2019/08 [Refereed][Not invited]
  • Eiji Hatta
    LANGMUIR 31 (35) 9597 - 9601 0743-7463 2015/09 [Refereed][Not invited]
    The shear response of three types of textures (mosaic, striation, and stripe) in 10,12-pentacosadiynoic acid solid Langmuir monolayers has been investigated with Brewster angle microscopy. Low temperature mosaic textures respond to an applied stress elastically. Upon the application of shear the change of contrast appears in the form of propagation of fronts roughly perpendicularly to the shear direction within a single domain reversibly, while the domain shape keeps constant since it is presumably frozen kinetically. The striation and stripe textures at high temperatures show a viscoplastic behavior (plastic bending) in its rheological response, being consistent with the formation of a dislocation wall (tilt boundary) through dislocation dynamics (dislocation glide and climb). The stress-induced formation of a tilt boundary provides a manifestation of the collective motion of a number of dislocations.
  • E. Hatta, T. Nishimura
    JOURNAL OF COLLOID AND INTERFACE SCIENCE 391 111 - 115 0021-9797 2013/02 [Refereed][Not invited]
    The dependence of the size of the cooperative unit (C.U.) of amphiphilic molecules on surface pressure (pi) in the liquid expanded (LE)-liquid condensed (LC) phase coexistence region of Langmuir monolayers has been formulated and calculated using measured isotherm data. The C.U. size changes largely depending on the surface pressure in the coexistence region: these submicroscopic molecular aggregates are not static objects, but dynamic ones characterized by large fluctuations in size. It has been found that the C.U. size distribution can be a natural consequence of the significant change of monolayer compressibility, which reflects large molecular area density fluctuations, in the coexistence region. (C) 2012 Elsevier Inc. All rights reserved.
  • E. Hatta
    LANGMUIR 27 (17) 10400 - 10406 0743-7463 2011/09 [Refereed][Not invited]
    Shape instabilities in single-component, saturated fatty acid membrane tubes have been investigated using phase contrast microscopy. These tubes were created in the course of a Langmuir monolayer collapse transition. Two types of shape instabilities were observed: (i) the excitation of a bending mode of a single tube, and (ii) topological changes of an assembly of tubes. The development of tube bending was accompanied by a shape transition from extended amphiphilic globules to confined ones that were transported in the tube. The evolution of bending instability has been analyzed as a balance among the bending energy, the surface tension energy of the tube, and the hydrodynamic dissipation energy by the surrounding fluid. Topological changes of an assembly of tubes were initiated by the formation of a membrane passage connecting two opposing tubes and followed by tube fusion and breaking. These changes were interpreted as a result of surface tension-gradient driven molecules transport on the tube surface.
  • E. Hatta
    JOURNAL OF PHYSICAL CHEMISTRY B 112 (29) 8571 - 8577 1520-6106 2008/07 [Refereed][Not invited]
    The motion of fatty acid vesicles driven by adhesion gradients of a liquid substrate (Langmuir monolayer) has been investigated. Trajectories of the vesicle motion reveal not only heterogeneity among vesicles in different regions of the monolayer but also heterogeneity within single-vesicle trajectories. Trajectories often exhibit complex behaviors such as circular and oscillating ones. Some vesicles exhibit intermittent dynamics that results in jump diffusion trajectories. In many vesicles their mean square displacements and effective diffusion coefficients exhibit a wide range of behaviors: (i) simple Brownian, (ii) subdiffusive, (iii) superdiffusive, and (iv) their combined motions. Even in the resting regime that the vesicle does not move substantially it exhibits active fluctuations due to spatio-temporal variations of the adhesion gradients of the monolayer. The results are compared with those in motor protein-driven transport of micrometer-sized particles bound to the cytoskeletal network and polymerization motor transport in. the cell previously reported.
  • E. Hatta
    JOURNAL OF PHYSICAL CHEMISTRY B 111 (34) 10155 - 10159 1520-6106 2007/08 [Refereed][Not invited]
    The motion of vesicles created through Langmuir monolayer collapse has been investigated. The vesicles grow only in a narrow molecular area range, and they exhibit remarkable, various biological cell-like behaviors such as division (cell division in cell biology, cytokinesis) and self-propulsion (motility). The vesicle division includes some dynamic modes: (i) an expulsion of a single satellite vesicle from an initial vesicle, (ii) a hierarchical and a sequential expulsion of a satellite vesicle, and (iii) a successive expulsion of two satellite vesicles from an initial vesicle. Two neighboring vesicles often show alternate fusion and division between them. Strong shape fluctuations dominate through vesicle division. The vesicles created exhibit distinct motions depending on the molecular area. At a large molecular area where most initial vesicles are created, they show a continuous, random motion on a few tens of micrometers length scale with a strong shape fluctuation and a constant velocity fluctuation profile. At a small molecular area they cease to move and shape fluctuations also become suppressed. At an intermediate molecular area there coexist vesicles with different dynamic modes: some vesicles show random motion similar to that at a large molecular area, but in a less fluctuating manner, while others exhibit a directional motion with an intermittent velocity jump. The directional motion is characterized by three distinct steps, i.e., extension, adhesion, and retraction. The characteristic motion is discussed from the viewpoint of haptotaxis, or the motion driven by adhesion gradients on the monolayer created by the local transfer of charged surfactant molecules between the vesicle and the monolayer, which the vesicle adheres to.
  • Electron Tunneling Spectroscopic Studies of Electron-Phonon Interactions and Density of States in the State-of-the Art Thermoelectric Semiconductors
    Nagao, J, Hatta, E
    Recent Research Developments in Applied Physics 9 21 - 54 2006 [Refereed][Not invited]
  • E Hatta
    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 74 (11) 3124 - 3125 0031-9015 2005/11 [Refereed][Not invited]
  • E Hatta, TM Fischer
    JOURNAL OF PHYSICAL CHEMISTRY B 109 (7) 2801 - 2804 1520-6106 2005/02 [Refereed][Not invited]
    The static and dynamic string defect textures connecting pairs of half-integer disclinations have been observed by Brewster angle microscopy in the solid phase of pentacosadiynoic acid Langmuir monolayers. The static string defect structures have appeared coexisting with two kinds of point disclinations that have four and two black brushes. The use of local laser heating has allowed one to observe kinetics of creation and annihilation of string defects connecting the two-half-integer disclinations in the splitting process of an s = 1 point disclination into fractional disclinations. These kinetics have been analyzed by studying the competition between the orientational elasticity of the molecules and the line tension of the string and the drag force of the disclinations.
  • E Hatta
    LANGMUIR 20 (10) 4059 - 4063 0743-7463 2004/05 [Refereed][Not invited]
    Unusual sequential collapse transitions are investigated in a lignoceric acid Langmuir monolayer. The nucleation of monolayer collapse is first initiated in the solid, S, phase but at remarkably low surface pressure where small three-dimensional (3D) granular dots appear. The density of nucleation centers increases, and the 3D dots prevail over the monolayer (surface roughening regime) as the surface pressure increases, but individual dots neither grow very much in size nor evolve into other shapes such as stripes or elongated dots. On further compression the second collapse mode manifests itself by highly anisotropic, global crack arrays (anisotropic cracking regime) where the surface pressure "kink" appears in the isotherm. In the latter regime, various forms of 3D curved filaments develop in the crack regions, and they break into smaller fragments with a typical relaxation time (similar to60 ms).
  • Imaging soft matters across dimensions: Collapse transitions in langmuir monolayers
    HATTA, E
    Recent Research Developments in Physical Chemistry 7 241 - 260 2004 [Refereed][Not invited]
  • VM Svistunov, YF Revenko, MA Belogolovskii, AY Gerasimenko, AI Khachaturov, YG Pashkevich, E Hatta
    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 72 (8) 2124 - 2125 0031-9015 2003/08 [Refereed][Not invited]
  • E Hatta, TM Fischer
    JOURNAL OF PHYSICAL CHEMISTRY B 107 (26) 6406 - 6410 1520-6106 2003/07 [Refereed][Not invited]
    Integer s = 1 point disclination textures of the molecular orientation of a pentacosadiynoic acid Langmuir monolayer split into two s = 1/2 defects upon laser heating. We explain this behavior by a competition of the line tension of a pi-wall of the c-director connecting both defects with the continuum orientation elastic energy. While the line tension causes an attraction, the orientation elastic energy mediates a repulsive interaction between the half-integer disclinations. Laser heating of the texture locally induces an anisotropic stress in the orientationally ordered solid phase, forcing the molecular orientation into the monolayer plane and thereby reducing the pi-wall line tension.
  • E Hatta, J Nagao
    PHYSICAL REVIEW E 67 (4) 41604 - 41608 1539-3755 2003/04 [Refereed][Not invited]
    A transition from surface-roughening collapse to a random network collapse has been investigated in fatty acid Langmuir monolayers. In contrast to the random network crack pattern, the surface-roughening crack pattern grows on a much longer time scale and on a much shorter length scale. A change in the isotherm from a surface pressure "spike" to a "plateau" occurs at the transition. In the surface-roughening regime, the pattern is manifested by the emergence of a three-dimensional (3D) disordered stripe phase with locally aligned, anisotropic stripe clusters. The individual stripes coalesce less with each other even at a late stage of the collapse process and there is a characteristic length for the stripe width and the nearest neighbor spacing. The pattern includes a high density of topological defects such as single open ends, twin open ends, branches, and loops. The effects of shear deformation on the observed patterns are discussed.
  • Foam Morphology as a High Order Structure Model of a Layer System
    Ishii T, Hatta E, Mukasa K
    Transaction of the Materials Research Society of Japan 28 7 - 9 2003 [Refereed][Not invited]
  • AI Khachaturov, E Hatta, VM Svistunov
    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 72 (1) 131 - 134 0031-9015 2003/01 [Refereed][Not invited]
    Electron tunneling between a Fermi metal and a narrow band conductor with non-quadratic E-k relationship is treated. It is shown that the tunneling characteristics of such junctions are very sensitive to barrier parameters. This sensitivity is supposed to be a main reason for disagreements among experimental data.
  • E. Hatta, J. Nagao
    Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 67 (4) 5  1063-651X 2003 [Refereed][Not invited]
    A transition from surface-roughening collapse to a random network collapse has been investigated in fatty acid Langmuir monolayers. In contrast to the random network crack pattern, the surface-roughening crack pattern grows on a much longer time scale and on a much shorter length scale. A change in the isotherm from a surface pressure “spike” to a “plateau” occurs at the transition. In the surface-roughening regime, the pattern is manifested by the emergence of a three-dimensional (3D) disordered stripe phase with locally aligned, anisotropic stripe clusters. The individual stripes coalesce less with each other even at a late stage of the collapse process and there is a characteristic length for the stripe width and the nearest neighbor spacing. The pattern includes a high density of topological defects such as single open ends, twin open ends, branches, and loops. The effects of shear deformation on the observed patterns are discussed. © 2003 The American Physical Society.
  • J Nagao, D Nataraj, M Ferhat, T Uchida, S Takeya, T Ebinuma, H Anno, K Matsubara, E Hatta, K Mukasa
    JOURNAL OF APPLIED PHYSICS 92 (7) 4135 - 4137 0021-8979 2002/10 [Refereed][Not invited]
    Electron tunneling experiments were performed on YbyCo4Sb12-Al oxide-Al junctions for y=0-0.25 at 4.2 K. In the second derivative tunneling spectrum of CoSb3 compound (y=0), three peaks were observed at around 5, 20, and 33 mV, which are closely related to an optical phonon mode with a rigid rectangle, Sb-Sb bond bending and bond stretching, and a large Co atomic motion, respectively. Appearance of the strong peak at 7 mV observed in Yb-filled samples corresponds to a rattled phonon mode of Yb ions. The peak energy due to the Sb-Sb bonds is unchanged, whereas the one due to Co motions shifts to lower with increasing Yb concentration. This fact indicates that the filled Yb ions strongly interact to the host framework Co atoms, which were clearly observed in the change of tunneling conductance. (C) 2002 American Institute of Physics.
  • E Hatta, TM Fischer
    LANGMUIR 18 (16) 6201 - 6206 0743-7463 2002/08 [Refereed][Not invited]
    Textures of the molecular orientation of molecules in a Langmuir monolayer of pentadecanoic acid (PDA) are compared with similar textures of monomeric and polymeric pentacosadiynoic acid (PCA) monolayers. Both acids PDA and PCA (monomeric and polymeric) exhibit stripe textures with characteristic modulations of the molecular orientation. Using laser heating, we may cleave or deform the stripes in monomeric PCA. The relaxation of the stripes reveals that the stripes in monomeric PCA are solid stripes with a finite Young's modulus of the order E = 5-30 mN/m in contrast to those in PDA, which are hexatic with a vanishing Young's modulus.
  • MA Belogolovskii, YF Revenko, AY Gerasimenko, VM Svistunov, E Hatta, G Plitnik, VE Shaternik, EM Rudenko
    LOW TEMPERATURE PHYSICS 28 (6) 391 - 394 1063-777X 2002/06 [Refereed][Not invited]
    We report a study of the electron tunneling transport in point-contact junctions formed by a sharp Ag tip and two different highly correlated oxides, namely, a magnetoresistive manganite La0.66Ca0.34MnO3 and a superconducting cuprate LaBa2Cu3O7-x. Strong chemical modifications of the oxide surface (supposedly, oxygen ion displacements) caused by applying high voltages to the junctions have been observed. This effect is believed to be responsible for an enormous growth of inelastic tunneling processes across a transition region that reveals itself in an overall V-shaped conductance background, with a strong temperature impact. The mechanism of the inelastic scattering is ascribed to charge transmission across magnetically active interfaces between two electrodes forming the junction. To support the latter statement, we have fabricated planar junctions between Cr and Ag films with an antiferromagnetic chromium oxide Cr2O3 as a potential barrier and at high-bias voltages have found an identical conductance trend with a similar temperature effect. (C) 2002 American Institute of Physics.
  • Z Khattari, E Hatta, P Heinig, P Steffen, TM Fischer, R Bruinsma
    PHYSICAL REVIEW E 65 (4) 41603 - 41611 1539-3755 2002/04 [Refereed][Not invited]
    Cavitation in liquid expanded and liquid condensed Langmuir monolayers induced by laser heating or microbubble coalescence is studied experimentally using fluorescence and Brewster angle microscopy. The kinetics of hole closure of two-dimensional (2D) gaseous cavitation bubbles exhibits a decelerated dynamics for cavities surrounded by a liquid expanded phase and an accelerated dynamics for cavities in a liquid condensed phase. Most of the cavities in liquid condensed phases possess a nonconvex shape and do not close. The results are compared with theoretical predictions derived for 2D cavitation of liquid monolayers of different surface shear viscosities, and for solid monolayers with diffusive flux of vacancies and interstitials. While part of the theory is in qualitative agreement with the experiment, the experimentally observed hole persistence within the liquid condensed phases and the hole closure within liquid expanded phases remains to be explained. The technique of microbubble coalescence might be particularly useful for the study of the rheological properties of hexatic phases.
  • E Hatta, TM Fischer
    JOURNAL OF PHYSICAL CHEMISTRY B 106 (3) 589 - 592 1520-6106 2002/01 [Refereed][Not invited]
    An extensive study for Langmuir monolayer collapse is carried out to explore the generality of classification of their crack patterns (E. Hatta et al. Eur. Phys. J. 1999, B 11, 609) and to analyze crack kinetics in the anisotropic cracks. Upon compression of fatty acid monolayers beyond the collapse pressure three classes of fracture patterns, a surface roughening, random crack network, or anisotropic fracture, can be observed depending on chain length of the fatty acid, pH value, and ion concentration of the subphase. A statistical characterization of the anisotropic crack growth of Langmuir monolayer fracture is presented. Anisotropic cracks grow on a Co2+ water subphase as quasi-periodic modulations, branching off previously formed cracks, interrupted by the coalescence of modulation cracks. Slight changes in pH and concentration of Co2+ ions in the subphase cause drastic changes of the modulation crack coalescence rate. We suggest, that differences in the viscoelastic nature of the monolayer are the main causes for the three types of crack growth scenaria.
  • AY Gerasimenko, MA Belogolovskii, YF Revenko, OI Chernyak, VM Svistunov, VE Shaternik, EM Rudenko, E Hatta, T Sasaki
    PHYSICS OF THE SOLID STATE 44 (7) 1208 - 1211 1063-7834 2002 [Refereed][Not invited]
    Gadolinium- and chromium-based normal metal-insulator-metal tunnel junctions were studied. Spectral functions of the Gd and Cr electron-boson interaction were reconstructed, from which it follows that the magnetic subsystem plays a noticeable role in the electron transport in magnetic metals. (C) 2002 MAIK "Nauka/Interperiodica".
  • Z Khattari, E Hatta, DG Kurth, TM Fischer
    JOURNAL OF CHEMICAL PHYSICS 115 (21) 9923 - 9928 0021-9606 2001/12 [Refereed][Not invited]
    Cavitation bubbles in a two-dimensional metallo-supramolecular coordination polyelectrolyte amphiphile complex at the air-water interface are formed using laser heating. The cavitation threshold, the rupture kinetics, and the radius of the stationary cavitation gas bubble is measured with Brewster angle microscopy. The tensile strength of the two dimensional complex is estimated and characterized by a critical cavitation pressure. (C) 2001 American Institute of Physics.
  • J Nagao, T Ebinuma, T Uchida, S Takeya, M Ferhat, E Hatta, K Mukasa, H Anno, K Matsubara
    PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS 228 (3) 705 - 709 0370-1972 2001/12 [Refereed][Not invited]
    Electron tunneling experiments were performed on n-Co0.9Ni0.1Sb3-Al oxide-Al junctions measured at 4.2 K. A V-shape tunneling conductance curve with small zero bias offset is observed, which can be associated with disorder states. Comparing with the results on p-Co0.9Fe0.1Sb3 samples, it has been clarified that the Fe substitution leads to a stronger three-dimensional disorder state as compared to the case of Ni substitution. Magnetic susceptibility measurements suggest that the observed three-dimensional disorder state is mainly magnetic in nature.
  • E Hatta, T Sasaki, VM Svistunov, MA Belogolovskii, OI Chernyak, AI Khachaturov, AY Gerasimenko
    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 70 (7) 1865 - 1868 0031-9015 2001/07 [Refereed][Not invited]
    Tunneling spectroscopy measurements on normal state Gd-Gd oxide-Al junctions have been performed. Small deviations from the overall parabolic dependence of conductance on voltage were revealed and analyzed using a theoretical approach, taking into account interactions of tunneling electrons with elementary excitations in the oxide layer and metal electrodes. These processes have been studied by calculating the even and odd conductances that characterize the symmetrical (emission of oxide phonons) and asymmetrical (self-energy effects in electrodes) processes, respectively. It has been found that in gadolinium, one of the simplest magnetic metals known, an interaction of electrons with magnetic excitations is as important as the electron-phonon contribution. This result explains the difference between the calculated electron-phonon coupling parameters and the experimentally derived electron mass enhancement factors in magnetic rare-earth metals.
  • AI Khachaturov, E Hatta, VM Svistunov
    LOW TEMPERATURE PHYSICS 26 (11) 827 - 830 1063-777X 2000/11 [Refereed][Not invited]
    The contribution of the electron band of the semimetal to the differential conductance of a metal-insulator-semimetal tunnel junction is found. It is established that the tunneling conductance depends substantially on the barrier parameters. The conductance curve exhibits a convexity with a maximum that in general does not correspond to the edges of the band or to a saddle point of the band, as has been proposed previously. It is shown that the band structure is well resolved in the second derivative of the current with respect to the voltage, d(2)I/dV(2). (C) 2000 American Institute of Physics. [S1063-777X(00)00811-2].
  • E Hatta, VM Svistunov, YF Revenko, MA Belogolovskii, NA Doroshenko, G Plitnik
    MODERN PHYSICS LETTERS B 14 (22-23) 819 - 825 0217-9849 2000/10 [Refereed][Not invited]
    The observation of an anomalous temperature behavior of the differential conductance versus voltage curves in contacts formed by an Ag tip and a bulk ceramic LaBa2Cu3O7-x with T-c around 92 K is reported. For a wide range of temperatures from T-c to helium-liquid ones, we have found a crossover from curves typical for a pure conducting normal metal-superconductor interface up to Giaever tunneling characteristics with gap features shifted to high biases. We take into account the existence of a degraded interlayer with suppressed superconducting parameters between a normal injector and a superconducting bulk and interpret qualitatively the data in terms of mesoscopic proximity effects. We argue that as the temperature is decreased, (i) the electron localization in a disordered region is enhanced, and (ii) in the interlayer, inelastic scattering processes become more effective. The latter was considered as a result of the inelastic scattering rate changes for charge carriers interacting with magnetic excitations in the near-interface region of high-T-c compound junctions.
  • J Nagao, M Ferhat, H Anno, K Matsubara, E Hatta, K Mukasa
    APPLIED PHYSICS LETTERS 76 (23) 3436 - 3438 0003-6951 2000/06 [Refereed][Not invited]
    Electron tunneling experiments were performed on p-Col(1-x)Fe(x)Sb(3)-Al-oxide-Al junctions for x = 0 and x = 0.1 at 4.2 K. A U-shaped tunneling conductance curve obtained for polycrystalline p-CoSb3 clearly shows an energy-band gap of similar to 50 meV. For p-Co0.9Fe0.1Sb3 skutterudites, a strong zero-bias conductance anomaly is observed. This anomaly may be due to a structural disorder arising from defects such as vacancies and interstitial Fe atoms. (C) 2000 American Institute of Physics. [S0003-6951(00)00223-0].
  • J Nagao, M Ferhat, E Hatta, K Mukasa
    PHYSICA STATUS SOLIDI B-BASIC RESEARCH 219 (2) 347 - 349 0370-1972 2000/06 [Refereed][Not invited]
    Temperature variation of electrical conductivity in two crystallographic directions (sigma(parallel to) and sigma(perpendicular to)) of p-Bi2Te3 crystals has been measured. The anisotropic factor, sigma(parallel to)/sigma(perpendicular to), shows an exponential form involving an activation energy. This can be interpreted as an effect of defects between the layers on the electronic density of states.
  • T Matsuura, T Komatsu, E Hatta, Y Shimoyama
    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS 39 (4A) 1821 - 1825 0021-4922 2000/04 [Refereed][Not invited]
    We report the results of structural investigations on Langmuir (L) and Langmuir-Blodgett (LB) films of tetra-tert-butyl phthalocyanine (MTBPC) containing various transition metal ions. Techniques were developed for fabricating well-ordered L-monolayers using a how-orientation method that dramatically enhances the molecular orientation of MTBPC in L-monolayers as compared to other techniques. The dilution procedure for developing solutions enables the formation of a well-defined single L-monolayer at the air-water interface. The tilt angles of MTBPCs in the L-monolayers are estimated by the limiting area technique. The tilting structure of LB films of MTBPCs on glass substrates as measured by X-ray diffraction (XRD) method is in good agreement with the estimate obtained by the limiting area technique on the corresponding L-monolayers. An annealing procedure significantly improves the ordering of the LB films as measured by XRD.
  • VM Svistunov, YV Medvedev, VY Tarenkov, AI D'yachenko, E Hatta, M Mukasa, R Aoki, H Szymczak, S Lewandowski, J Leszczynski
    JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS 91 (3) 547 - 552 1063-7761 2000 [Refereed][Not invited]
    Tunneling experiments were performed on ceramic samples with the composition La0.6Sr0.4MnO3, manifesting negative magnetoresistance. Two types of contacts were studied: symmetric (break junction type) and asymmetric ceramic-insulator-metal contact. A high magnetic-field sensitivity of the conductivity sigma(H) of the contacts was observed even when only one of the electrodes was magnetic. The effect was explained by the existence of spin-polarized localized states in the tunneling barrier. Their appearance was attributed to the formation of an oxygen-depleted, magnetically two-phase state of localized ferromagnetic nanoregions in an antiferromagnetic dielectric matrix in the near-contact region. (C) 2000 MAIK "Nauka/ Interperiodica".
  • VM Svistunov, VY Tarenkov, AI D'yachenko, E Hatta
    JETP LETTERS 71 (7) 289 - 292 0021-3640 2000 [Refereed][Not invited]
    Spectroscopic studies of the silver-optimum-doped Bi2223 contacts show that the temperature dependence of the parameter Delta follows the BCS curve. However, the tunnel measurements performed for the same series of specimens did not reveal any temperature dependence of the energy gap Delta. The feature observed in the tunnel density of states was retained at temperatures T > T-c, manifesting the presence of the temperature-independent pseudogap E-p. The difference between the data obtained with tunnel spectroscopy and Andreev reflection spectroscopy is explained by the fact that the latter measures the true superconducting energy gap Delta(s)(T), whereas the peaks of the tunneling conductivity are related to the total energy gap Delta of cuprates, which includes both the parameter Delta(s) and the pseudogap E-p: Delta approximate to root Delta(s)(2) + E-p(2). (C) 2000 MAIK "Nauka / Interperiodica".
  • E Hatta, T Maekawa, K Mukasa, Y Shimoyama
    PHYSICAL REVIEW B 60 (21) 14561 - 14564 1098-0121 1999/12 [Refereed][Not invited]
    The dc susceptibilities have been measured on cobalt stearate (CoSt(2)) Langmuir-Blodgett (LB) multilayer films. Two successive peaks and irreversibility are observed clearly in both parallel and perpendicular directions to the c axis. These behaviors are consistent with the mean-field theory for the Heisenberg-type spin-glass system having a weak single-ion anisotropy. The above behavior has never been observed in small CoSt(2) particles, so it is considered to be an inherent characteristic in the LB film structure. The magnetic behaviors between CoSt(2) LB films and other related compounds are compared: and discussed. [S0163-1829(99)03142-2].
  • E Hatta, D Suzuki, J Nagao
    EUROPEAN PHYSICAL JOURNAL B 11 (4) 609 - 614 1434-6028 1999/10 [Refereed][Not invited]
    The morphology on collapsed monolayers at the air-water interface has been studied using phase contrast microscopy. It is found that the transition from randomly distributed to quasi-one dimensional crack pattern takes place, depending on the pH value of the subphase and the presence of specific divalent metal ions. In these macroscopic patterns, the former exhibits a surface roughening due to a monolayer buckling while the latter becomes more smooth and uniform. The occurrence of the former is instantaneous and the latter follows a slow dynamics, i.e., the crack propagation in monolayers occurs with a delay for crack nucleation. Thus the change of pattern indicates the existence of a dynamic transition. The transition is discussed with the scenario of a crack instability in brittle materials. The changes of viscous nature and of ion binding, and the compression direction probably operate for the observed behavior effectively.
  • H Hosoi, S Nagashima, E Hatta, K Sueoka, K Mukasa
    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS 38 (9A) 5239 - 5243 0021-4922 1999/09 [Refereed][Not invited]
    Using scanning tunneling microscopy (STM) and X-ray diffraction (XRD) studies, we find that a 500-nm-thick KxC60 (x = 3) thin film deposited on a gold thin film grown on a mica substrate has the face-centered cubic (fcc)-(311) surface and that a KxC60 (x = 4) film of the same thickness has the body-centered tetragonal(bct)-(112) surface. The potassium density x of a KxC60 thin him is estimated by in situ measurement of the exposure time dependence of the sheet resistance of the film in potassium vapor. STM images of the K3C60 thin film, which are different from the reported images of C-60 thin films, indicate that the observed surface is a fcc-K3C60 (311) surface. The images also show that the lattice constant of the potassium-doped C-60 thin film is about 0.5% larger than that of a nondoped one along (0 (1) over bar 1). From the I-V characteristics of the KxC60 films as measured by STM, it is found that the band gap of films vary with the value of x in KxC60 films.
  • J Nagao, E Hatta, K Mukasa
    JOURNAL OF APPLIED PHYSICS 86 (3) 1477 - 1479 0021-8979 1999/08 [Refereed][Not invited]
    Inelastic electron tunneling experiments have been performed in Bi0.94Sb0.06-Al oxide-Al junctions. A strong peak observed at 1.9 mV in the second derivative tunnel spectra is closely related to the estimated effective Debye temperature, besides intervalley acoustic and optical phonon structures. This structure clearly corresponds to the electron-intravalley acoustic phonon coupling. (C) 1999 American Institute of Physics. [S0021-8979(99)06115-0].
  • Y Iwata, H Kobayashi, S Kikuchi, E Hatta, K Mukasa
    JOURNAL OF CRYSTAL GROWTH 203 (1-2) 125 - 130 0022-0248 1999/05 [Refereed][Not invited]
    The variation of in situ reflection high-energy electron diffraction (RHEED) patterns was observed for the study of crystal quality of Bi2Te3/Sb2Te3 multilayer films on sapphire (0001) substrates during molecular beam epitaxy (MBE) growth. At the initial stage of growth, the RHEED pattern shows a superposition of spots and streaks which indicates the existence of three-dimensional island growth. Moreover, weak streaks between fundamental streaks, which indicate rotation around the c-axis, are observed. It is found that a clear streaky pattern(1 x 1) gradually appears with the growth of larger grains. The existence of heterointerfaces in Bi2Te3/Sb2Te3 multilayer films is confirmed from the X-ray diffraction (XRD) measurements and the depth profile of Auger electron spectroscopy (AES) measurements. (C) 1999 Elsevier Science B.V. All rights reserved.
  • J Nagao, H Unuma, E Hatta, K Mukasa
    PHYSICA STATUS SOLIDI B-BASIC RESEARCH 213 (1) 253 - 258 0370-1972 1999/05 [Refereed][Not invited]
    We measured tunneling conductance of Al-Al oxide-p-Bi2Te3 tunnel junctions. A small increase of the tunneling conductance was observed in the energy gap region. The intensity of the increase of tunneling conductance decreased by annealing the p-Bi2Te3 films. Therefore, it is considered that this increase in tunneling conductance is closely related to energy states caused by defects in p-Bi2Te3 films. For the first time, energy states caused by defects are revealed by tunneling experiments in p-Bi2Te3 films.
  • J Nagao, T Shiino, S Kikuchi, T Yoshimoto, E Hatta, K Mukasa
    JOURNAL OF PHYSICS D-APPLIED PHYSICS 32 (2) 134 - 138 0022-3727 1999/01 [Refereed][Not invited]
    The structure of antimony and bismuth thin firms grown on glass or Si(001) substrates by ionized cluster beam (ICB) deposition was characterized. X-ray diffraction measurements were carried out to investigate the structures of the films. The dependence of the crystalline orientation in antimony films grown on the glass substrate on the applied voltage was observed. With increasing applied voltage, the x-ray diffraction peaks from the (001) planes become weak and those from the (0ll) planes become relatively strong. In bismuth films deposited on the Si(001) substrate at V-a = 3 kV, the dominant crystal face is the (012) plane. These results show that the crystalline orientation of antimony and bismuth films can be controlled well according to the applied voltage and substrates used in the ICE deposition.
  • J Nagao, E Hatta, K Mukasa
    JOURNAL OF APPLIED PHYSICS 83 (9) 4807 - 4809 0021-8979 1998/05 [Refereed][Not invited]
    Inelastic electron tunneling experiments have been performed in p-Bi2Te3-Al oxide-Al junctions. Strong peaks due to electron-acoustic phonon coupling are observed in the second derivative tunnel spectrum. These phonon structures are closely related to the effective Debye temperature. This gives direct evidence that the electron-acoustic phonon scattering plays a dominant role in p-Bi2Te3. (C) 1998 American Institute of Physics.
  • E Hatta, H Hosoi, H Akiyama, T Ishii, K Mukasa
    EUROPEAN PHYSICAL JOURNAL B 2 (3) 347 - 349 1434-6028 1998/04 [Refereed][Not invited]
    We have observed a remarkable two-armed spiral in the collapse process of a floating monolayer at the air-water interface by phase contrast microscopy. This demonstrates that the floating monolayer as a form of soft condensed matter reorganizes itself due to a certain kind of macroscopic or collective behavior of molecules as it collapses. This pattern formation is caused by the breakdown of a critical dynamical balance between the deformation of solid domain and the applied surface pressure. The fragility as well as the flexibility of the floating monolayer can be associated with the observed pattern growth. There are also observed interesting, periodically arranged collections of molecules in numerous collapsed regions.
  • H Hosoi, H Akiyama, E Hatta, T Ishii, K Mukasa
    We observed stearic and lignoceric acids, and their mixed fatty acid monolayers at the air-water interface in situ using phase contrast microscopy. Tt was found that these monolayers exhibit quite different cohesion processes depending on the surface pressure. For stearic acid, the domains of the monolayer on the subphase have smooth surfaces and change their shapes to cover free areas with increasing surface pressure. In contrast; the domains of lignoceric acid divide into a number of smaller domains to cover free areas as surface pressure increased. We also found that the domains of lignoceric acid monolayers have internal substructures (i.e., triangular and inhomogeneous). For the mixed fatty acid monolayers, we clearly observed that some domains have the same internal substructures as those of single component monolayers. These facts demonstrate that a phase contrast microscope is a powerful tool for investigating the cohesion process of fatty acid monolayer sat the air-water interface without the need for any probe material.
  • E Hatta, K Mukasa
    SOLID STATE COMMUNICATIONS 103 (4) 235 - 238 0038-1098 1997/07 [Refereed][Not invited]
    Electron tunneling experiments have been performed to study the one-particle density of states in inhomogeneous Sb films. A zero bias anomaly can be well described in terms of the theory of weakly disordered metals. On the other hand, the background conductance at higher voltages exhibits roughly a parabolic shape, which is typical in a metal-oxide-metal tunnel junction. The feature of the band structure in the semimetal disappears completely. This result indicates that an inhomogeneous Sb film constitutes a metallic, degenerate electron gas system at the junction interface. A metastable metallic phase may be stabilized due to a higher disorder. (C) 1997 Elsevier Science Ltd.
  • E Hatta, M Tonokawa, J Nagao, K Mukasa
    SOLID STATE COMMUNICATIONS 102 (6) 437 - 439 0038-1098 1997/05 [Refereed][Not invited]
    Systematic tunneling measurements have been performed on A/Al oxide/Ni1-xMnx junctions to study the one-particle density of states in spin glass Ni1-xMnx (x = 0.24-0.35) films where the lattice and spin disorders coexist. The strong zero bias conductance anomaly indicating the metal-insulator transition was observed at a critical concentration x(c) approximate to 0.24. This is the direct evidence that the variation of the tunneling conductance is largely due to the magnetic disorder. (C) 1997 Elsevier Science Ltd.
  • S Kikuchi, Y Iwata, E Hatta, J Nagao, K Mukasa
    Thin Bi2Te3 films were grown on Al2O3(0001) substrates with molecular beam epitaxy (MBE). X-ray diffraction (XRD) was used to confirm the orientation and crystalline quality of the films, the c-axis was oriented normal to the film surface. It was found that the full width at half-maximum intensity (FWHM) of diffraction peaks in XRD pattern depends on the deposition conditions such as substrate temperature and the flux ratio. The reflection high-energy electron diffraction (RHEED) pattern of the deposited films shows a streak pattern at the initial stage of growth. Electrical resistivity, carrier concentrations and Hall mobility were measured in the temperature range from 77K to 300K. The film with narrower FWHM exhibited a lower carrier concentration (5.1 X 10(19) cm(3)) and electrically intrinsic characteristics around room temperatures. For the first time a clear separation of slopes of the Hall mobility in thin Bi2Te3 film is observed. On the other hand, the films with wider FWHM, which have higher carrier concentrations, exhibited a metallic behavior. The electrical properties are closely related to the variation of FWHM of diffraction peaks in the XRD pattern.
  • E Hatta, K Mukasa
    SOLID STATE COMMUNICATIONS 98 (4) 293 - 296 0038-1098 1996/04 [Refereed][Not invited]
    Electron tunneling measurements have been performed to investigate the anisotropic effect in both the band structure and the phonons of semimetal antimony films. Depending upon the texturization of antimony films, the definite change in shape of the tunnel conductance is observed and the intravalley acoustic phonon peak becomes apparent as well as the intervalley acoustic and optical phonon peaks in the second derivatives. Furthermore, the overtone phonon peak exhibits an asymmetric structure contrary to that of the Raman spectrum. This asymmetry is not observed in point contact spectra.
  • E Hatta, J Nagao, K Mukasa
    JOURNAL OF APPLIED PHYSICS 79 (3) 1511 - 1514 0021-8979 1996/02 [Refereed][Not invited]
    We have calculated tunneling conductance in metal-narrow-gap-semiconductor (NGS)-metal tunnel junctions. Flietner's two-band model is used to describe the dispersion relation within the energy gap in an isotropic NGS with different conduction- and valence-band edge effective masses. The results are compared with the tunneling conductance calculated by Kane's two-band model, which has been commonly used to describe the tunneling characteristics through the energy gap in semiconductors. These results propose that the tunneling conductance in the tunnel junctions in which a narrow gap semiconductor of largely different conduction- and valence-band effective masses is used as a tunneling barrier can exhibit quite a different behavior, especially in the region of the midgap, from the tunneling conductance described by Kane's two-band model. (C) 1996 American Institute of Physics.
  • MATSUSAKA Hiromi, HATTA Eiji, ISHII Toshio, MUKASA Koichi
    J. Surf. Sci. Soc. Jpn. The Surface Science Society of Japan 17 (7) 412 - 416 0388-5321 1996 [Refereed][Not invited]
    We have investigated the structure and magnetic property of manganese stearate films prepared by Langmuir-Blodgett (LB) method. From the (00l) Bragg peak of the X-ray diffraction pattern, it is found that the films deposited on quartz substrates are Y-type LB film and Mn2+ ions in the film are arranged two-dimensionally with a lattice spacing of about 48.8 Å. The angular dependence of the (00l) Bragg peak intensity obtained from the structure factor of manganese stearate LB films calculated is consistent with the experimental data. Using SQUID magnetometry, the magnetic moment of the films was measured down to 1.7 K with applied magnetic field of 100 Oe perpendicular to the film surfaces. The susceptibility behaves according to the Curie-Weiss law in high temperature ranges and gradually deviates from the law below about 20 K. Comparing the magnetic moments measured at 1.7 K with two different applied magnetic fields perpendicular and parallel to the film surface, we observed magnetic anisotropy.
  • J Nagao, E Hatta, K Mukasa
    VACUUM 46 (12) 1377 - 1380 0042-207X 1995/12 [Refereed][Not invited]
    We have measured tunnel spectra of Sn/Sn oxide/Pb tunnel junctions. Sn oxide phonon spectra are largely affected by humidity conditions. Certain anomalous behaviours are observed in wet-prepared Sn/Sn oxide/Pb tunnel junctions. The intensity of vibrational modes of molecules adsorbed on the Sn oxide is observed to be much weaker than that of molecules adsorbed on the Al oxide. And the shape of CH stretching vibrational modes is quite different from that in Al/Al oxide/Pb tunnel junctions.
    ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER 98 (1) 33 - 37 0722-3277 1995/07 [Refereed][Not invited]
    Tunnel experiments have been performed on Au/Sb2Te3/Al tunnel junctions to study elastic interelectrode tunneling through the small energy gap of a narrow-gap semiconductor. Tunnel conductance exhibited narrow width conductance peak at zero bias voltage. This behaviour is in accordance with the result of the theoretically calculated tunnel conductance, in which the nonparabolic dispersion relation within the energy gap of the narrow-gap semiconductor used as a tunnel barrier in a metal/narrow-gap semiconductor/metal tunnel structure is included. And some interesting structures are also observed in the conductance curves.
    THIRTEENTH INTERNATIONAL CONFERENCE ON THERMOELECTRICS (316) 247 - 249 0094-243X 1995 [Refereed][Not invited]
    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS 33 (6A) 3528 - 3530 0021-4922 1994/06 [Refereed][Not invited]
    Large domains in a diacetylene derivative (10, 12-pentacosadiynoic acid) monomer monolayer at the air-water interface were obtained by spreading a solution of relatively high concentration. Uniformly oriented large domains of over 20 mm x 5 mm were prepared when the area of water surface was slowly increased by moving a barrier after the highly concentrated solution was spread on a small bounded water surface.
    MATERIALS SCIENCE AND ENGINEERING 99 285 - 288 0025-5416 1988/03 [Refereed][Not invited]


Research Projects

  • 日本学術振興会:科学研究費助成事業
    Date (from‐to) : 2022/04 -2025/03 
    Author : 八田 英嗣
  • Ministry of Education, Culture, Sports, Science and Technology:Grants-in-Aid for Scientific Research(基盤研究(C))
    Date (from‐to) : 2006 -2007 
    Author : Eiji HATTA
    We developed a combined system of Brewster angle microscopy with laser tweezers. This system enables one to initiate and to observe the nonequilibrium, Marangoni-driven directional growth of condensed domains of Langmuir monolayers in the field of view of the monitor upon local laser heating on them. By using the system directional growth of condensed domains on the water surface is found to be classified mainly by two types of morphologies. One is fractal domain, and the other is dendrite structure. In the latter one, side branches on one side to the main branch were selectively grown, I.e...
  • 文部科学省:科学研究費補助金(萌芽研究)
    Date (from‐to) : 2004 -2005 
    Author : 八田 英嗣
    1.水面上単分子膜におけるずり流動場誘起分子再配向との比較として、ずり流動場よりも配向弾性が分子再配向に主要な役割を果たす場合の理論的研究を行った。その結果、±2のトポロジカルチャージを有するトポロジカル双極子として記述されるInverse boojumの場合、トポロジカル双極子相互作用によりそれらがある特定の角度で配列し、それに伴い、周囲の膜構成分子の再配向が生じることが可能であることが示された。2.ずり流動場セルによる分子再配向実験との比較として、ペンタコサジイン酸固相単分子膜に対する光ピンセット局所加熱実験を行った。この結果、固相膜に対する点状フォースによる分子再配向ダイナミクスの記述には、ずり流動場の効果を導入することが本質的であることが明らかになった。3.ずり流動場セルとブリュースター角顕微鏡の複合システムを自作した後、このシステムを用いて上記固相水面上単分子膜のストライプテクスチャーに対するずり流動場誘起分子再配向の実験を行った。その結果、2.に記述したテクスチャー変化の領域に比べてはるかに広い領域で、かつダイナミックに、テクスチャーコントラストの特徴的な変化がみられた。この変化は大きく、2つの点で特徴づけられる。それらは、1)ずり流動場下でのストライプ上のコントラストの明確な変化(黒白反転)、2)ストライプのずり変形に伴うshear waveの伝播現象である。こ...
  • Ministry of Education, Culture, Sports, Science and Technology:Grants-in-Aid for Scientific Research(基盤研究(B))
    Date (from‐to) : 2003 -2004 
    Author : Eiji HATTA
    The combined system of Brewster angle microscope with optical tweezers has been constructed. Integer s=1 point disclination textures of the molecular orientation of a pentacosadiynoic acid Langmuir monolayr split into two s=1/2 defects upon laser heating. We explain this behavior by a competition of the line tension of a π-wall of the c-director connecting both defects with the continuum orientation elastic energy. While the line tension causes an attraction, the orientation elastic energy mediates a repulsive interaction between the half-integer disclinations. Laser heating of the texture ...
  • 日本学術振興会:科学研究費助成事業
    Date (from‐to) : 1996 -1996 
    Author : 八田 英嗣
    (1)V-VI族ナロ-ギャップ半導体Sb_2Te_3をトンネル障壁に用いたトンネル接合におけるトンネルコンダクタンスに観測されるコンダクタンスピークならびにアンダーシュート構造に関しての知見を得るためにAu/Sb_2Te/Alトンネル接合を作製し、温度、印加磁場を変化させながらトンネル分光測定を行った。 (2)Au/Sb_2Te/Teトンネル接合はトンネル接合作製用真空蒸着装置を用いて作製した。まず、下部電極であるAu薄膜を約50nm成膜を行った後、Sb_2Te_3薄膜は同ペレットを用いてフラッシュ蒸着法により成膜を行った。最後に上部電極であるAl薄膜を約100nm成膜を行った。界面の汚れを避けるために、これらの行程は全て真空を切ることなく行われた。この結果、液体ヘリウム温度(4.2K)で約400-800Ωのトンネル抵抗値が得られた。 (3)(2)で作製した試料のトンネルコンダクタンス測定は1.5-4.2Kで行われた。その結果、観測された0 meVでのコンダクタンスピークは温度の減少とともに半値幅の単調な減少が認められた。また、磁場印加の効果に関しては0-500ガウスの範囲内でトンネルコンダクタンスの形状は磁場印加に依存しないことが確認された。以上の測定結果からはトンネルコンダクタンスの特異な形状に関しての起源に関して明確な結論を導くには至っておらず、今後の課題としてはさらに高磁場でのコンダクタンス測定が行われる必要があるように思われる。
  • 日本学術振興会:科学研究費助成事業
    Date (from‐to) : 1992 -1992 
    Author : 八田 英嗣

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