岩佐和晃 Kazuaki Iwasa


茨城大学フロンティア応用原子科学研究センター
 (研究部門)
   319-1106 茨城県那珂郡東海村白方162-1 いばらき量子ビーム研究センターD310
   電話: 029-352-3238 FAX: 029-287-7872
   e-mail: kazuaki.iwasa.ifrc @ vc.ibaraki.ac.jp

Frontier Research Center for Applied Atomic Sciences, Ibaraki University
 (Reseach Devision)
   Shirakata 162-1, Tokai, Naka, Ibaraki 319-1106, JAPAN
   tel: +81-29-352-3238, fax: +81-29-287-7872
   e-mail: kazuaki.iwasa.ifrc @ vc.ibaraki.ac.jp

略歴:
   1990年3月 慶應義塾大学理工学部物理学科卒業
          (卒業論文:「混合原子価白金錯体の構造に関するX線回折実験」)
   1992年3月 慶應義塾大学大学院理工学研究科物理学専攻修士課程修了
          (修士論文:「磁気弾性効果による結晶格子の変調構造」)
   1995年3月 慶應義塾大学大学院理工学研究科物理学専攻博士課程修了、博士(理学)
          (博士論文:「Neutron Scattering Studies of Low-Dimensional and Random Magnetic Systems」)
   1995年4月 東京都立大学理学部物理学科助手
   1997年4月 東京都立大学大学院理学研究科物理学専攻助手
   2003年7月 東北大学大学院理学研究科物理学専攻助教授(その後、准教授)
   2016年4月 茨城大学フロンティア応用原子科学研究センター教授

研究分野:
   希土類元素を含むf電子強相関化合物における電子状態(磁性・構造)
      ・R3T4Sn13におけるカイラル電子状態
      ・RT2Zn20における多極子自由度
      ・希土類充填スクッテルダイトにおける全対称型電子自由度秩序
      ・CexLa1-xB6の多極子相
      ・GdB6, DyB6など希土類硼化物におけるカゴ状構造のソフトフォノンと構造相転移
      ・Ceモノプニクタイト
      ・Yb4As3
   ランダム磁性体の相転移
      ・Rb2CocMg1-cF4
   上記の中性子およびX線散乱による実験的研究と装置
      ・東北大学理学部偏極中性子分光器TOPAN(日本原子力研究所改3号原子炉JRR-3Mに設置)

所属学会:
   日本物理学会
   日本中性子科学会

研究論文の抜粋:
 1. K. Iwasa, M. Kohgi, Y. Haga, T. Suzuki, K. Kakurai, M. Nishi, K. Nakajima, P. Link, A. Gukasov, J.-M. Mignot:
 "Polarized-neutron study on 4f-electron wave functions of magnetic-polaron state in CeP",
 J. Phys. Chem. Solids 60 (1999) 1185-1188.

 2. K. Iwasa, A. Hannan, M. Kohgi, T. Suzuki:
 "Direct Observation of the Modulation of the 4f-electron Orbital State by Strong p-f mixing in CeSb",
 Phys. Rev. Lett. 88 (2002) 207201-1 - 4.

 3. K. Iwasa, M. Kohgi, A. Gukasov, J.-M. Mignot, N. Shibata, A. Ochiai, H. Aoki, T. Suzuki:
 "Staggered-field effect on the magnetic-field-induced magnetization of the one-dimensional antiferromagnet Yb4As3",
 Phys. Rev. B 65 (2002) 052408-1 - 4.

 4. K. Iwasa, Y. Watanabe, K. Kuwahara, M. Kohgi, H. Sugawara, T. D. Matsuda, Y. Aoki and H. Sato:
 "Crystal-Structure Modulation in the Anomalous Low-Temperature Phase of PrFe4P12",
 Physica B 312-313 (2002) 834-836.

 5. K. Iwasa, K. Kuwahara, M. Kohgi, P. Fischer, A. Donni, L. Keller, T. C. Hansen, S. Kunii, N. Metoki, Y. Koike, K. Ohoyama:
 "Neutron-Diffraction Study of the Unusual Ordered Phases of Ce0.75La0.25B6",
 Physica B 329-333 (2003) 582-583.

 6. Kazuaki Iwasa, Lijie Hao, Keitaro Kuwahara, Masahumi Kohgi, Shanta Ranjan Saha, Hitoshi Sugawara, Yuji Aoki, Hideyuki Sato, Takashi Tayama and Toshiro Sakakibara:
 "Evolution of 4f-Electron States in the Metal-Insulator Transition of PrRu4P12",
 Phys. Rev. B 72 (2005) 024414-1 - 5.

 7. Kazuaki Iwasa, Lijie Hao, Tomoo Hasegawa, Toshiaki Takagi, Kenji Horiuchi, Yoshiaki Mori, Youichi Murakami, Keitaro Kuwahara, Masahumi Kohgi, Hitoshi Sugawara, Shanta Ranjan Saha,Yuji Aoki and Hideyuki Sato:
 "Role of p-f Hybridization in the Metal-Nonmetal Transition of PrRu4P12",
 J. Phys. Soc. Jpn. 74 (2005) 1930-1933.

 8. Keitaro Kuwahara, Kazuaki Iwasa, Masahumi Kohgi, Naofumi Aso, Masafumi Sera, and Fumitoshi Iga:
 "Detection of Neutron Scattering from Phase IV of Ce0.7La0.3B6: A Confirmation of the Octupole Order",
 J. Phys. Soc. Jpn. 76 (2007), 093702-1 - 4.

 9. Kazuaki Iwasa, Lijie Hao, Tomoo Hasegawa, Kenji Horiuchi, Youichi Murakami, Junya Otsuki, Yoshio Kuramoto, Masahumi Kohgi, Keitaro Kuwahara, Hitoshi Sugawara, Yuji Aoki, and Hideyuki Sato:
"Magnetic Excitations in Heavy Electron State of Filled Skutterudite PrxLa1-xFe4P12 (x = 1.00 and 0.85)",
J. Phys. Soc. Jpn. 77 (2008). 063706-1-4.

 10. Kazuaki Iwasa, Kotaro Saito, Youichi Murakami, and Hitoshi Sugawara:
"Electronic hybridization effect on 4f electron crystal field states of PrOs4P12" ,
Phys. Rev. B 79 (2009) 235113-1-6.

 11. K. Iwasa, K. Saito, Y. Murakami and H. Sugawara:
"Temperature evolution of crystal field splitting in Pr-filled skutterudite",
J. Phys.: Conf. Ser. 200 (2010) 012071 (4pp).

 12. K. Iwasa, R. Igarashi, K. Saito, C. Laulhe, T. Orihara, S. Kunii, K. Kuwahara, H. Nakao, Y. Murakami, F. Iga, M. Sera, S. Tsutsui, H. Uchiyama, and A. Q. R. Baron:
"Motion of the guest ion as precursor to the first-order phase transition in the cage system GdB6",
Phys. Rev. B 84 (2011) 214308-1-6.

 13. Kazuaki Iwasa, Lijie Hao, Masahumi Kohgi, Keitaro Kuwahara, Jean-Michel Mignot, Hitoshi Sugawara, Yuji Aoki, Tatsuma D. Matsuda, and Hideyuki Sato:
"Magnetic Excitation in Totally Symmetric Staggered Ordered Phase of PrFe4P12",
J. Phys. Soc. Jpn. 81 (2012) 094711 (9 pages).

 14. Kazuaki Iwasa, Hiroki Kobayashi, Takahiro Onimaru, Keisuke T. Matsumoto, Naohiro Nagasawa, Toshiro Takabatake, Seiko Ohira-Kawamura, Tatsuya Kikuchi, Yasuhiro Inamura and Kenji Nakajima:
"Well-Defined Crystal Field Splitting Schemes and Non-Kramers Doublet Ground States of f Electrons in PrT2Zn20 (T = Ir, Rh, and Ru)",
J. Phys. Soc. Jpn. 82 (2013) 043707 (5 pages).

15. Kotaro Saito, Claire Laulhe, Takahiro Sato, Lijie Hao, Jean-Michel Mignot, and Kazuaki Iwasa:
"Emergence of reentrant metal-nonmetal transition in Pr0.85Ce0.15Ru4P12 and Pr(Ru0.95Rh0.05)4P12",
Phys. Rev. B 89 (2014) 075131-1-8 (Received 8 October 2013; published 24 February 2014).

16. Kazuaki Iwasa, Ari Yonemoto, Shigeru Takagi, Shinichi Itoh, Tetsuya Yokoo, Soshi Ibuka, Chihiro Sekine and Hitoshi Sugawara:
"Nd-ion substitution effect on f-electron multipole order of PrRu4P12",
Physics Procedia 75 (2015) 179186 (Selection and peer-review under responsibility of the Scientific Programme Committee of ICM 2015, Accepted on September 14 2015, Available online 29 December 2015).

(その他の論文情報は、研究室の研究成果にて参照ください。)

国際会議での成果発表の抜粋(口頭発表):
 1. K. Iwasa, M. Kohgi, A. Gukasov, J.-M. Mignot, A. Ochiai, H. Aoki and T. Suzuki:
  "Polarized Neutron Study of Anisotropic Magnetic response under Fields in the Charge Ordered Phase of Yb4As3"
  International Conference on Magnetism 2000 "ICM2000" (Oral contribution),
  Recife, Brazil, Aug. 6 - Aug. 11, 2000.

 2. L. Hao, K. Iwasa, M. Nakajima, D. Kawana, K. Kuwahara, M. Kohgi, H. Sugawara, T. D. Matsuda, Y. Aoki and H. Sato:
  "Antiferro-quarupolar ordering of 4f-electron state in the filled skutterudite PrFe4P12"
  International Conference on Strongly Correlated Electron Systems "SCES2002" (Oral contribution),
  Krakow, Poland, 10-13 July, 2002.

 3. K. Iwasa, L. Hao, K. Kuwahara, M. Kohgi , S. R. Saha, H. Sugawara, Y. Aoki and H. Sato:
  "Drastic Evolution of 4f-electron States in the Metal-Insulator Transition of PrRu4P12"
  International Conference on Strongly Correlated Electron Systems "SCES2004" (Oral contribution),
  Karlsruhe, Germany, 26-30 July, 2004.

 4. Kazuaki Iwasa:
  "Role of p-f Hybridization in the Metal-Nonmetal Transition of PrRu4P12"
  Joint Workshop on NQP-Skutterudites and BPM in Multi-Approach (invited),
  Hachioji (Tokyo, Japan), 21 - 24 November, 2005.

 5. K. Iwasa:
  "Field induced magnetic moment distribution in the ordered phase of PrFe4P12"
  International Conference on "New Quantum Phenomena in Skutterudite and Related Systems" (invited),
  Kobe Univ., 26 - 30 Sep. 2007.

 6. K. Iwasa, K. Saito, Y. Murakami, and H. Sugawara:
  “Temperature evolution of crystal field splitting in PrOs4P12"
  International Conference on Magnetism 2009 "ICM2009" (Oral contribution),
  Karlsruhe, Germany, July 26 - 31, 2009.

 7. K. Iwasa, R. Igarashi, K. Saito, C. Laulhe, T. Orihara, S. Kunii, K. Kuwahara, H. Nakao, Y. Murakami, F. Iga, M. Sera, S. Tsutsui, H. Uchiyama, and A. Q. R. Baron:
  “Phonon Softening in GdB6"
  The 13th International Conference on Phonon Scattering in Condensed Matter, "PHONONS2010" (Oral contribution),
  National Taiwan University, Taipei, Taiwan, April 18 - 23, 2010.

8. K. Iwasa:
  "New aspects of electronic ordered states due to f2 configuration of Pr-based systems"
  Neutron Applications on Strongly Correlated Electron Systems (NASCES11)(Invited),
  IQBRC, Tokai, Japan, February 23 - 25, 2011.

9. K. Iwasa and F. Iga:
  "Nucleation of metastable superlattice in soft anharmonic phonon systems RB6 (R = Gd and Tb)"
  The 15th International Conference on Phonon Scattering in Condensed Matter, "Phonons2015" (oral presentation in Session Mo1: Light, Neutron and X-ray scattering, July 13, 2015),
  University of Nottingham, United Kingdom, July 12-17, 2015.

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Last update on April 30, 2016.