Yukio Kajihara

Last Updated :2026/09/02

Affiliations, Positions
Graduate School of Advanced Science and Engineering, Associate Professor
E-mail
kajiharahiroshima-u.ac.jp
Self-introduction
I study disordered materials (*) from the view point of physics. * materials without long periodic order such like liquids and glasses

Basic Information

Academic Degrees

  • Doctor of Science, Kyoto University
  • Master of Science, Kyoto University

Educational Activity

  • [Bachelor Degree Program] School of Integrated Arts and Sciences : Department of Integrated Arts and Sciences : Integrated Arts and Sciences
  • [Master's Program] Graduate School of Advanced Science and Engineering : Division of Advanced Science and Engineering : Physics Program
  • [Master's Program] Graduate School of Advanced Science and Engineering : Division of Advanced Science and Engineering : Transdisciplinary Science and Engineering Program
  • [Doctoral Program] Graduate School of Advanced Science and Engineering : Division of Advanced Science and Engineering : Physics Program
  • [Doctoral Program] Graduate School of Advanced Science and Engineering : Division of Advanced Science and Engineering : Transdisciplinary Science and Engineering Program

Research Fields

  • Mathematical and physical sciences;Physics;Mathematical physics / Fundamental condensed matter physics

Research Keywords

  • Physics of disordered materials
  • liquid-liquid transition
  • fluctuation
  • x-ray
  • Supercritical Fluid
  • Fluid Metal
  • Metal Nonmetal Transition

Educational Activity

Course in Charge

  1. 2026, Liberal Arts Education Program1, 3Term, Experimental Methods and Laboratory Work in Physics I
  2. 2026, Liberal Arts Education Program1, 1Term, Experimental Methods and Laboratory Work in Physics I
  3. 2026, Liberal Arts Education Program1, 3Term, Experimental Methods and Laboratory Work in Physics I
  4. 2026, Liberal Arts Education Program1, 4Term, Experimental Methods and Laboratory Work in Physics II
  5. 2026, Liberal Arts Education Program1, 2Term, Experimental Methods and Laboratory Work in Physics II
  6. 2026, Liberal Arts Education Program1, 4Term, Experimental Methods and Laboratory Work in Physics II
  7. 2026, Liberal Arts Education Program1, 3Term, Fundamental PhysicsI
  8. 2026, Undergraduate Education, Second Semester, Laboratory Work in Natural Sciences
  9. 2026, Undergraduate Education, Second Semester, Practical Methods in Natural Sciences
  10. 2026, Undergraduate Education, 1Term, Introduction to Physical Sciences
  11. 2026, Undergraduate Education, 3Term, Laboratory Work in Material Sciences A
  12. 2026, Undergraduate Education, 3Term, Experimental Methods for Materials Sciencs A
  13. 2026, Undergraduate Education, 1Term, Statistical Physics I
  14. 2026, Undergraduate Education, 1Term, Physics of Complex Liquids and Soft Matters
  15. 2026, Undergraduate Education, 2Term, Frontiers of Material Science
  16. 2026, Graduate Education (Master's Program) , 2Term, Seminar in Integrated Arts and Sciences
  17. 2026, Graduate Education (Master's Program) , 3Term, Transdisciplinary Science and Engineering Program Common Subjects 1 (Smart Development)
  18. 2026, Graduate Education (Master's Program) , 2Term, Fundamentals of Complex Matter

Research Activities

Academic Papers

  1. Sound speed and positive dispersion in GexSe100-x glasses (x=5, 15, 25, and 33) by high-resolution inelastic X-ray scattering, JOURNAL OF NON-CRYSTALLINE SOLIDS, 683, 20260615
  2. Temperature variation of the longitudinal acoustic excitation dispersion curve in liquid Ge15Te85 by high-resolution inelastic x-ray scattering, JOURNAL OF PHYSICS-CONDENSED MATTER, 38(12), 20260327
  3. ★, Existence of density inhomogeneity of liquid Te associated with liquid-liquid phase transition, JOURNAL OF PHYSICS-CONDENSED MATTER, 36(34), 20240828
  4. Observation of plasmon excitation in liquid silicon by inelastic x-ray scattering, JOURNAL OF PHYSICS-CONDENSED MATTER, 36(7), 20240221
  5. Collective modes in molten CsCl, CuCl and AgI observed by inelastic x-ray scattering, JOURNAL OF MOLECULAR LIQUIDS, 390, 20231115
  6. Phonon dispersion curves in the type-I crystalline and molten clathrate compound Eu8Ga16Ge30, JOURNAL OF PHYSICS-CONDENSED MATTER, 35(11), 20230322
  7. ★, Experimental observation of mesoscopic fluctuations to identify origin of thermodynamic anomalies of ambient liquid water, PHYSICAL REVIEW RESEARCH, 5(1), 20230216
  8. Structural changes across thermodynamic maxima in supercooled liquid tellurium: A water-like scenario, Proc. Natl. Acad. Sci., 119, e2202044119:1-e2202044119:7, 20220606
  9. Experimental Observation of Maximum Density Fluctuation in Liquid Te, arXiv, 2201(10065), 1-5, 20220125
  10. Structural changes across thermodynamic maxima in supercooled liquid tellurium: a water-like scenario, arXiv, 2201(06838), 1-24, 20220118
  11. Low energy excitation in liquid Sb and liquid Bi observed in inelastic x-ray scattering spectra, JOURNAL OF PHYSICS-CONDENSED MATTER, 33(47), 20211124
  12. Experimental Observation of Mesoscopic Fluctuations to Identify Origin of Thermodynamic Anomalies of Ambient Liquid Water, arXiv, 2111(06589), 1-14, 20211112
  13. Longitudinal acoustic and higher-energy excitations in the liquid phase-change material Ge2Sb2Te5, PHYSICAL REVIEW B, 104(6), 20210816
  14. Structural studies on fluid Hg and fluid Se at high temperatures and high pressures by means of X-ray diffraction and small angle X-ray scattering, ZEITSCHRIFT FUR PHYSIKALISCHE CHEMIE-INTERNATIONAL JOURNAL OF RESEARCH IN PHYSICAL CHEMISTRY & CHEMICAL PHYSICS, 235(1-2), 3-24, 20210218
  15. Furnace for Inelastic X-Ray Scattering from Liquids up to 1600 degrees C, PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, 257(11), 20201101
  16. X-Ray Compton Scattering Study of Liquid Sodium at Elevated Temperatures, PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, 257(11), 20201101
  17. Static density response function studied by inelastic x-ray scattering: Friedel oscillations in solid and liquid Li, PHYSICAL REVIEW B, 102(5), 20200821
  18. Peculiar temperature dependence of dynamical sound speed in liquid Se50Te50 by inelastic x-ray scattering, JOURNAL OF PHYSICS-CONDENSED MATTER, 32(21), 20200513
  19. ★, Experimental observation of density fluctuations in liquid metals associated with liquid-liquid, liquid-gas and metal-nonmetal transitions, J. Phys.: Condens. Matter, 32, 274001, 20200407
  20. Detection of collective optic excitations in molten NaI, CONDENSED MATTER PHYSICS, 22(4), 20190819
  21. Structural studies on fluid sulfur at high temperatures and high pressures: I. Atomic dynamics investigated by inelastic x-ray scattering, J. Non-Crystalline Solids, 522, 119571-1-119571-6, 20190715
  22. Dynamical sound speed and structural inhomogeneity in liquid Te studied by inelastic x-ray scattering, J. Non-Crystalline Solids: X, 1, 100006-1-100006-6, 20190112
  23. Static and dynamic structures of liquid Ba8Ga16Sn30: a melt of the thermoelectric clathrate compounds, JOURNAL OF PHYSICS-CONDENSED MATTER, 30(45), 20181114
  24. Plasmons in Liquid Rb at Elevated Temperatures Studied by Inelastic X-ray Scattering, J. Phys. Soc. Jpn., 87, 084703-1-084703-7, 20180718
  25. Viscoelastic anomaly accompanying anti-crossing behaviour in liquid As2Se3, JOURNAL OF PHYSICS-CONDENSED MATTER, 30(28), 20180622
  26. Peculiar atomic dynamics in liquid GeTe with asymmetrical bonding: Observation by inelastic x-ray scattering, PHYSICAL REVIEW B, 97(17), 20180514
  27. X-ray Compton Scattering Study of Liquid Germanium and Tin, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 86(12), 124703-1-124703-6, 20171215
  28. Asymmetrical bonding in liquid Bi disentangled by inelastic X-ray scattering, EPJ Web. of Conf.(EPJ Web. of Conf.), 06001-1-06001-7, 20170821
  29. Dispersion relations of the acoustic modes in divalent liquid metals, EPJ Web. of Conf., 151, 06002-1-06002-6, 20170821
  30. Inelastic x-ray scattering measurements of liquid waterglycerol mixtures, EPJ Web. of Conf., 151, 06003-1-06003-8, 20170821
  31. Isotactic poly(4-methyl-1-pentene) melt as a porous liquid: Reduction of compressibility due to penetration of pressure medium, JOURNAL OF CHEMICAL PHYSICS, 146(19), 20170521
  32. Charge inhomogeneity in an expanded fluid metal: X-ray Compton scattering observation, EPL, 117(1), 20170228
  33. ★, Experimental Verification of Liquid-liquid Critical Point Hypothesis from the View Point of `Fluctuations', The Review of High Pressure Science and Technology, 26(4), 288-296, 20161227
  34. Phonon Excitations in Pd40Ni40P20 Bulk Metallic Glass by Inelastic X-Ray Scattering, Mater. Sci. Forum, 879, 767-772, 20161201
  35. Critical Indices nu and gamma Experimentally Obtained at the Liquid-Vapor Critical Point in Fluid Hg, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 85(3), 20160315
  36. Anomalous dispersion of the acoustic mode in liquid Bi, PHYSICAL REVIEW B, 92(5), 20150825
  37. Inelastic x-ray scattering studies on dynamic structure factor of polymeric liquid Se under pressure, AIP conf. Proc., 1673, 020002, 20150817
  38. X-ray Compton scattering experiments for fluid alkali metals at high temperatures and pressures, AIP Conf. Proc., 1673, 020004, 20150817
  39. Inelastic X-ray Scattering Study on Plasmon Dispersion in Liquid Cs, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 84(8), 20150815
  40. Transverse excitations in liquid Fe, Cu and Zn, Journal of Physics: Condensed Matter, 27(19), 194104-1-7, 20150520
  41. Microscopic Elastic Properties of Polycrystalline Mg85Zn6Y9 Alloy with Long-Period Stacking Ordered 18R Phase Investigated by Inelastic X-ray Scattering, MATERIALS TRANSACTIONS, 56(7), 914-916, 20150327
  42. Inelastic x-ray scattering study of plasmon dispersions in solid and liquid Rb, PHYSICAL REVIEW B, 89(1), 20140129
  43. Electron momentum density in liquid silicon, PHYSICAL REVIEW B, 88(11), 20130916
  44. Chemical order in liquid As2Se3 at high temperatures obtained by X-ray scattering and reverse Monte Carlo modeling, JOURNAL OF NON-CRYSTALLINE SOLIDS, 366, 22-29, 20130415
  45. Transverse excitations in liquid Sn, JOURNAL OF PHYSICS-CONDENSED MATTER, 25(11), 20130320
  46. Transverse excitations in liquid metals, AIP Conf. Proc, 1518, 695-702, 20130301
  47. ★, Density fluctuations at the continuous liquid-liquid phase transition in chalcogen systems, PHYSICAL REVIEW B, 86(21), 20121206
  48. Static and dynamical inhomogeneity at liquid - liquid phase transition of Se-Te mixtures, EPJ Web of Conference, 15, 02002, 20110501
  49. Synchrotron radiation studies of an expanded fluid alkali metal, Eur. Phys. J. Special Topics, 196, 95-107, 20110501
  50. Transverse excitations in liquid Ga, Eur. Phys. J. Special Topics, 196, 85-93, 20110501
  51. Inelastic x-ray scattering measurements of dynamical cross-over in liquid As2Se3 at high temperature and high pressure, Eur. Phys. J. Special Topics, 196, 167-174, 20110501
  52. Packing structure of chains and rings in an expanded liquid Se80Te20 mixture near the semiconductor to metal transition, Journal of Physics: Condensed Matter, 22, 455103, 20101001
  53. Small-angle x-ray scattering and density measurements of liquid Se50-Te50 mixture at high temperatures and high pressures using synchrotron radiation, Journal of Physics: Conference Series, 215, 012078, 20100301
  54. Wide and small angle X-ray scattering measurements of supercritical water using synchrotron radiation, Journal of Physics: Conference Series, 215, 012090, 20100301
  55. Icosahedral ordering in liquid iron studied via x-ray scattering and Monte Carlo simulations, PHYSICAL REVIEW B, 80(18), 20091105
  56. Icosahedral ordering in liquid iron studied via x-ray scattering and Monte Carlo simulations, Physical Review B, 80, 180201, 20091101
  57. Transverse Acoustic Excitations in Liquid Ga, Physical Review Letters, 102, 105502, 20090313
  58. ★, Dynamical inhomogeneity of liquid Te near the melting temperature proved by inelastic x-ray scattering measurements, Journal of Physics: Condensed Matter, 20, 494244, 20081210
  59. Collective dynamics of As2Se3 glass investigated by inelastic X-ray scattering, Journal of Non-Crystalline Solids, 354, 2715-2718, 20080501
  60. Small-angle x-ray scattering of supercritical fluid Hg: Bi-impurity effect, Journal of Physics: Conference Series, 98, 012002, 20080306
  61. Structural study of expanded fluid cesium, Journal of Physics: Conference Series, 98, 012003, 20080306
  62. X-ray diffraction measurements of expanded fluid sulfur up to the supercritical region, Journal of Physics: Conference Series, 98, 012008, 20080306
  63. Structural fluctuations in expanded fluid Se accompanying the semiconductor-metal transition, J. Phys.: Conference series, 98, 012028, 20080306
  64. Dynamical structure in liquid Te using inelastic x-ray scattering: from semiconductor-metal transition to metallic regime, Journal of Physics: Conference Series, 98, 022001, 20080306
  65. Viscoelastic narrowing of a collective mode in molten CsCl observed by inelastic x-ray scattering, Journal of Physics: Condensed Matter, 19(46), 466110, 20071121
  66. X-ray diffraction measurement of liquid As2Se3 by using third-generation synchrotron radiation, JOURNAL OF NON-CRYSTALLINE SOLIDS, 353(18-21), 1985-1989, 20070615
  67. Thermal radiation method: proposal of a new technique for measuring interfacial or surface fluctuations, JOURNAL OF APPLIED CRYSTALLOGRAPHY, 40, S687-S690, 20070401
  68. Electrical Resistivity of Carbon Micro Coil Measured by Multi-Probe Unit Installed in a Scanning Electron Microscope, Japanese Journal of Applied Physics, 44, 6867-6869, 20050908
  69. X-Ray Absorption and De-Excitation Processes of Krypton Clusters Studied by the XAFS-PEPICO Synchronous Measurements, Physica Scripta, T115, 984-985, 20050401
  70. ★, Optical emissivity study of the critical fluctuations in mercury wetting film on sapphire, Journal of Physics: Condensed Matter, 15, 6179-6198, 20030917
  71. Slow structural relaxation in liquid Te-Se mixtures, Journal of Non-Crystalline Solids, 312-314, 361-365, 20020401
  72. Slow dynamics due to the metal-nonmetal transition in liquid mercury, Journal of Non-Crystalline Solids, 312-314, 265-268, 20020401
  73. Size-selective EXAFS spectroscopy of free selenium clusters, Physical Review Letters, 89, 243401, 20020401
  74. Two-dimensional supercritical fluid mercury formed on a sapphire substrate, Journal of Non-Crystalline Solids, 312-314, 472-480, 20020401
  75. Critical fluctuations of mercury wetting film on sapphire, Journal of Non-Crystalline Solids, 312-314, 489-493, 20020401
  76. Mercury wetting film on sapphire, Physical Review E, 63, 051601, 20010501
  77. Dielectric relaxation measurements on methanol up to the super critical region, Journal of Physics: Condensed Matter, 13, 10307-10320, 20010401
  78. Wetting Phenomena of Mercury on Sapphire Studied by Optical Emissivity Measurement, Journal of Physics: Condensed Matter, 12, 375-381, 20000401
  79. Anomalous sound attenuation in liquid Te50Se50 mixture under high pressure, Journal of Physics: Condensed Matter, 12, 7323-7339, 20000401
  80. Dielectric relaxation of water and heavy water in the whole fluid phase, The Journal of Chemical Physics, 110, 3026-3036, 19990401
  81. Sound attenuation in super critical fluid mercury, Journal of Non-Crystalline Solids, 250-252, 139-143, 19990401
  82. Wetting Phenomena at Mercury-Sapphire Interface under High Temperature and Pressure, Journal of Non-Crystalline Solids, 250-252, 209-213, 19990401
  83. Ellipsometric Study of Prewetting Transition at Mercury-Sapphire Interface, Journal of Physics: Condensed Matter, 10, 11589-11594, 19980401

Invited Lecture, Oral Presentation, Poster Presentation

  1. Interpretation of the specific heat of liquids by focusing on critical fluctuations associated with phase transitions, Yukio Kajihara, IIS UTokyo SYMPOSIUM: Soft and Liquid Matter Physics: Past, Present and Future, 2025/03/12, Without Invitation, English
  2. Simple idea to solve Kauzmann paradox of glass transition phenomena, Yukio Kajihara, Masanori Inui, Ayano Chiba, 14th International Conference on the Structure of Non-Crystalline Materials, 2019/11/08, Without Invitation, English, Kobe, Japan
  3. Another scenario for glass transition phenomena, Yukio Kajihara, Masanori Inui, Ayano Chiba, 14th International Conference on the Structure of Non-Crystalline Materials, 2019/11/04, Without Invitation, English, Kobe, Japan
  4. Density fluctuations of supercooled liquid Te, Y. Kajihara, Y. Kajihara, M. Inui, K. Ohara, K. Matsuda and T. Hagiya, The 17th international conference on Liquid and Amorphous Metals (LAM17), 2019/08/30, Without Invitation, English, Lyon in France
  5. Where Come from Dynamic Heterogeneity in Glass Transition? : Similarity with Liquid-Liquid Transition, Y. Kajihara, M. Inui and A. Chiba, Y. Kajihara, M. Inui and A. Chiba, 8th International Discussion Meeting on Relaxations in Complex Systems, 2017/07/26, Without Invitation, English, Wisla, Poland
  6. Ultrasonic Sound Velocity Measurements for Liquid Water-Glycerol Mixtures, K. Nukumizu, Y. Kajihara and M. Inui, K. Nukumizu, Y. Kajihara and M. Inui, 8th International Discussion Meeting on Relaxations in Complex Systems, 2017/07/24, Without Invitation, English, Wisla, Poland
  7. Simple scenario for glass transition phenomena based on liquid-liquid transition framework, Y. Kajihara, M. Inui, A. Chiba, Y. Kajihara, M. Inui, A. Chiba, 10th Liquid Matter Conference, 2017/07/17, Without Invitation, Japanese, European Physical Society, Ljubljana, Slovenia
  8. Inelastic x-ray scattering measurements of liquid water-glycerol mixtures, Y. Kajihara, Y. Kajihara, N. Shibata, M. Inui, K. Matsuda, S. Tsutsui, The 16th International Conference on Liquid and Amorphous Metals (LAM-16), 2016/09/06, Without Invitation, English, Bonn, Germany
  9. Sound velocity measurements of liquid water-methanol mixtures, N. Shibata, N. Shibata, Y. Kajihara, K. Nukumizu, M. Inui, S. Tsutsui, The 16th International Conference on Liquid and Amorphous Metals (LAM-16), 2016/09/06, Without Invitation, English, Bonn, Germany
  10. Time concept of entropy: from "fast sound" to glass transition, Y. Kajihara, Y. Kajihara, M. Inui and A. Chiba, The 16th International Conference on Liquid and Amorphous Metals (LAM-16), 2016/09/05, Without Invitation, English, Bonn, Germany
  11. "Fluctuations" in liquid water-alcohol mixtures, Y. Kajihara, Y. Kajihara, M. Inui, S. Di Fonzo, M. Saito, C. Masciovecchio, S. Tsutsui and A.Q.R. Baron, 9th Liquid Matter Conference (Liquids2014), 2014/07/22, Without Invitation, English, European Physical Society, Lisbon, Portugal
  12. "Fast sound" measurements for liquid water-alcohol mixtures, Y. Kajihara, Y. Kajihara, S. Di Fonzo, M. Saito, C. Masciovecchio, M. Inui, S. Tsutsui and A.Q.R. Baron, 8th International Conference on Inelastic X-ray Scattering (IXS2013), 2013/08/13, Without Invitation, English, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
  13. Direct detection of fluctuations in liquids - new approach for liquid-liquid phase transition -, Y. Kajihara, Perugia university seminar, 2013/02/26, Without Invitation, English, Perugia University, Italy, Perugia University, Italy
  14. Direct detection of fluctuations in liquids - new approach for liquid-liquid phase transition -, Y. Kajihara, Sapienza University of Rome Seminar, 2013/02/12, Without Invitation, English, Sapienza University of Rome, Italy, Sapienza University of Rome, Italy
  15. Direct detection of fluctuations in liquids - new approach for liquid-liquid phase transition -, Y. Kajihara, Chalmers University Seminar, 2013/02/08, Without Invitation, English, Chalmers University, Sweden, Chalmers University, Sweden
  16. Study of liquid-liquid phase transitions of chalcogens and water using X-ray techniques, Y. Kajihara, Elettra Seminar, 2010/07/09, Without Invitation, English, Elettra, Italy, Elettra, Italy
  17. Phase transition of liquid Se-Te mixtures, Y. Kajihara, Y. Kajihara, M. Inui and K. Matsuda, International workshop on Phase-change materials and disordered materials - towards new functional materials, With Invitation, English, Osaka Science and Technology Center, Japan

External Funds

Acceptance Results of Competitive Funds

  1. KAKENHI, 2016, 2018
  2. KAKENHI, 2014, 2015
  3. KAKENHI, "Fast sound" phenomena and liquid-liquid phase transition in liquid water: direct measurement of fluctuations = Entropy, 2012, 2013
  4. KAKENHI, Effects of high-pressure environments on atomic dynamics in disordered materials with covalent bonds, 2011, 2013
  5. KAKENHI, Transverse phonon modes in liquids: Observation by inelastic x-ray scattering, 2010, 2012
  6. KAKENHI, Liquid dynamics at metal-nonmetal transition-Attempt at description of the phase transition through fluctuations-, 2008, 2010
  7. KAKENHI, Studies on anomalous dynamic properties in supercritical metallic fluids using a high-resolution inelastic x-ray scattering technique, 2008, 2010
  8. KAKENHI, 2005, 2006
  9. KAKENHI, Bonding, Fluctuations and Dynamics in Supercritical Metallic Fluids Using Synchrotron Radiation, 2004, 2006

Social Activities

Organizing Academic Conferences, etc.

  1. 2020/02, 2020/02
  2. 2017/08, 2017/08
  3. 2017/03, 2017/03
  4. 2014/09
  5. 2013/09
  6. 2012/08
  7. 2011/08
  8. 2010/11