Inelastic neutron scattering study of spin-charge coupling in spin-frustrated conductors

2012 Fiscal Year Final Research Report

• Project/Area Number: 22740209
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Single-year Grants
• Research Field: Condensed matter physics II
• Research Institution: Tohoku University
• Principal Investigator: TOMIYASU Keisuke 東北大学, 高等教育開発推進センター, 助教 (20350481)
• Project Period (FY): 2010 – 2012
• Keywords: 強相関系

Research Abstract

We clarified dynamic/static spin structures in spin-frustrated conductors by neutron scattering. Our study, for the first time, succeeded in observing antiferromagnetic pairs of two tetrahedral molecular spin ferromagnets as the origin of the anomalously heavy fermion behavior in LiV_2O_4, dynamical partial disorder-type structure in Mn_3Pt, and all-in all-out magnetic structure in Nd_2Ir_2O_7 with novel metal-insulator transition originating from spin-orbit coupling.

Research Products

• [Journal Article] Emergenceof Highly Degenerated Excited States inFrustrated Magnet MgCr2O4 (2013)
  • Author(s): K. Tomiyasu, T. Yokobori, Y. Kousaka, R.I. Bewley, T. Guidi, T. Watanabe, J. Akimitsu, and K. Yamada
  • Journal Title: Phys. Rev. Lett Volume: 110 Pages: 077205-1-5
  • DOI: DOI:10.1103/PhysRevLett.110.077205
  • Peer Reviewed
• [Journal Article] Observation of partial disorder-type spin fluctuations in frustrated Mn3Pt (2012)
  • Author(s): K. Tomiyasu, H. Yasui, and Y.Yamaguchi
  • Journal Title: J. Phys. Soc. Jpn Volume: 81 Pages: 114724-1-4
  • DOI: DOI:10.1143/JPSJ.81.114724
  • Peer Reviewed
• [Journal Article] Hydrogen release from Li alanates originates in molecular lattice instability emerging at~100 K (2012)
  • Author(s): K. Tomiyasu, T. Sato, K. Horigane, S.Orimo, and K. Yamada
  • Journal Title: Appl. Phys. Lett Volume: 100 Pages: 193901-1-3
  • DOI: DOI:10.1063/1.4712053
  • Peer Reviewed
• [Journal Article] Modified Cross-Correlation for Efficient White-Beam Inelastic Neutron Scattering Spectroscopy (2012)
  • Author(s): K. Tomiyasu, M. Matsuura, H. Kimura, K. Iwasa, K. Ohoyama, T. Yokoo, S. Itoh, E. Kudoh, T. Sato, and M. Fujita
  • Journal Title: Nucl. Instr. Meth. Phys. Res.A Volume: 677C Pages: 89-93
  • DOI: DOI:10.1016/j.nima.2012.03.001
  • Peer Reviewed
• [Journal Article] Emergence of magnetic long-range order in frustrated pyrochlore Nd2Ir2O7 with metal-insulator transition (2012)
  • Author(s): K. Tomiyasu, K. Matsuhira, K. Iwasa, M. Watahiki, S. Takagi, M. Wakeshima, Y. Hinatsu, M. Yokoyama, K. Ohoyama, and K. Yamada
  • Journal Title: J. Phys. Soc.Jpn Volume: 81 Pages: 034709
  • DOI: DOI:10.1143/JPSJ.81.034709
  • Peer Reviewed
• [Journal Article] Molecular Spin-Orbit Excitations in the J_<eff> = 1/2 Frustrated Spinel GeCo_2O_4 (2011)
  • Author(s): K. Tomiyasu, M. K. Crawford, D. T.Adroja, P. Manuel, A. Tominaga, S. Hara, H. Sato, T. Watanabe, S. I. Ikeda, J. W. Lynn, K. Iwasa, and K. Yamada
  • Journal Title: Phys. Rev. B Volume: 84 Pages: 054405
  • DOI: DOI:10.1103/PhysRevB.84.054405
  • Peer Reviewed
• [Journal Article] Molecular spin-liquid state in spin-3/2 frustrated spinel HgCr_2O_4 (2011)
  • Author(s): K. Tomiyasu, H. Ueda, M. Matsuda, M.Yokoyama, K. Iwasa, and K. Yamada
  • Journal Title: Phys. Rev. B Volume: 84 Pages: 035115
  • DOI: DOI:10.1103/PhysRevB.84.035115
  • Peer Reviewed
• [Journal Article] A spin molecule model for geometrically frustrated spinel ZnFe_2O_4 (2011)
  • Author(s): K. Tomiyasu and K. Kamazawa
  • Journal Title: J. Phys. Soc. Jpn Volume: 80 Pages: SB024
  • DOI: DOI:10.1143/JPSJS.80SB.SB024
  • Peer Reviewed
• [Journal Article] Neutron scattering study of spiral-type spin correlations in the frustrated spinel Mn_<0.07>Mg_<0.93>Cr_2O_4 (2011)
  • Author(s): T. Yokobori, K. Tomiyasu, Y. Kousaka, H.Matsui, H. Hiraka, K. Iwasa, K. Yamada, and J. Akimitsu
  • Journal Title: J. Phys.: Conf. Ser Volume: 320 Pages: 012039
  • DOI: DOI:10.1088/1742-6596/320/1/012039
  • Peer Reviewed
• [Journal Article] Stability of hexamer-type spin excitations in the frustrated spinel Mg1-xCr2O4-x (2011)
  • Author(s): Y. Kousaka, K. Tomiyasu, T. Yokobori, K.Horigane, H. Hiraka, K. Yamada, and J. Akimitsu
  • Journal Title: J. Phys.: Conf. Ser Volume: 320 Pages: 012040
  • DOI: DOI:10.1088/1742-6596/320/1/012040
  • Peer Reviewed
• [Journal Article] Crystalline electric field study in thepyrochlore Nd_2Ir_2O_7 with metal-insulator transition (2011)
  • Author(s): M. Watahiki, K. Tomiyasu, K.Matsuhira, K. Iwasa, M. Yokoyama, S. Takagi, M. Wakeshima, and Y. Hinatsu
  • Journal Title: J. Phys.: Conf. Ser Volume: 320 Pages: 012080
  • DOI: DOI:10.1088/1742-6596/320/1/012080
  • Peer Reviewed
• [Journal Article] Spin-orbit coupling inactivity of Co_<2+> ion in geometrically frustrated magnet GeCo_2O_4 (2011)
  • Author(s): K. Tomiyasu, A. Tominaga, S. Hara, H.Sato, T. Watanabe, S. I. Ikeda, H. Hiraka, K. Iwasa, and K. Yamada
  • Journal Title: J. Phys.: Conf. Ser Volume: 320 Pages: 012038
  • DOI: DOI:10.1088/1742-6596/320/1/012038
  • Peer Reviewed
• [Journal Article] 幾何学的フラストレート磁性体にひそむ階層的なスピン分子励起 (2011)
  • Author(s): 富安啓輔,山田和芳
  • Journal Title: 日本物理学会誌 Volume: 66(5) Pages: 口絵340&記事361
  • URL: http://ci.nii.ac.jp/naid/110008661941
  • Peer Reviewed
• [Journal Article] 中性子散乱による磁性研究ならびに評価手法の開発 (2010)
  • Author(s): 富安啓輔
  • Journal Title: 日本中性子科学会誌波紋 Volume: 20(3) Pages: 237-240
  • URL: http://ci.nii.ac.jp/naid/40017272519
  • Peer Reviewed
• [Presentation] スピネル型LiV_2O_4の粉末中性子非弾性散乱 (2013)
  • Author(s): 富安啓輔,植田浩明,飯久保智,新高誠司,河村聖子,中島健次
  • Organizer: 日本物理学会第68回年次大会
  • Place of Presentation: 広島大学
  • Year and Date: 2013-03-29
• [Presentation] 電子ドープLaCoO_3系の磁化・抵抗測定による研究 (2013)
  • Author(s): 小山俊一,綿引正倫,小野寺貢,富安啓輔
  • Organizer: 日本物理学会第68回年次大会
  • Place of Presentation: 広島大学
  • Year and Date: 2013-03-27
• [Presentation] 低スピン状態LaCoO_3系の極希薄不純物置換の本質 (2012)
  • Author(s): 富安啓輔,久保田祐貴,下村紗耶,中尾裕則,Sungdae Ji,梶本亮一
  • Organizer: 第4回J-PARC/MLFシンポジウム・茨城県ビームライン平成23年度成果報告会
  • Place of Presentation: 日本科学未来館
  • Year and Date: 2012-10-10
• [Presentation] 電子ドープLaCoO_3系の探索と磁化測定による評価 (2012)
  • Author(s): 小山俊一,綿引正倫,岩佐和晃,中尾裕則,富安啓輔
  • Organizer: 日本物理学会秋期大会
  • Place of Presentation: 横浜国立大学
  • Year and Date: 2012-09-21
• [Presentation] Coサイト希薄不純物置換LaCoO_3系の単結晶磁化測定と蛍光X線測定によるスピン状態ポーラロンの研究 (2012)
  • Author(s): 富安啓輔,久保田祐貴,下村紗耶,中尾裕則
  • Organizer: 日本物理学会秋期大会
  • Place of Presentation: 横浜国立大学
  • Year and Date: 2012-09-19
• [Presentation] Molecular spin excitations in frustrated spinel-type oxides (2012)
  • Author(s): K. Tomiyasu
  • Organizer: The International Conference on Highly Frustrated Magnetism 2012, McMaster University
  • Place of Presentation: Canada
  • Year and Date: 2012-06-07
• [Presentation] スピン分子-フラストレート格子における特異な磁気励起-,シンポジウム講演 (2012)
  • Author(s): 富安啓輔
  • Organizer: 日本物理学会第67回年次大会
  • Place of Presentation: 関西学院大学
  • Year and Date: 2012-03-25
• [Presentation] J-PARC偏極度解析中性子分光器POLANO計画の進展 (2012)
  • Author(s): *大山研司,岩佐和晃,伊藤晋一,横尾哲也,富安啓輔,松浦直人,平賀晴弘,藤田全基,木村宏之,佐藤豊人,佐藤卓,有馬孝尚,猪野隆,吉良弘,坂口佳史,奥隆之,有本靖,鈴木淳市,清水裕彦,武田全康,金子耕士,野尻浩之
  • Organizer: 日本物理学会第67回年次大会
  • Place of Presentation: 関西学院大学
  • Year and Date: 2012-03-25
• [Presentation] Spin-orbit coupling inactivity of Co^<2+> ion in geometrically frustrated magnet GeCo_2O_4 (2011)
  • Author(s): K. Tomiyasu, A. Tominaga, S. Hara, H.Sato, T. Watanabe, S. I. Ikeda, H. Hiraka, K. Iwasa and K. Yamada
  • Organizer: International Conference on Frustration in Condensed Matter 11
  • Place of Presentation: Sendai (Japan)
  • Year and Date: 20110100
• [Presentation] 希薄濃度領域における不純物置換LaCoO_3系の中性子非弾性散乱と磁化測定による研究 (2011)
  • Author(s): 富安啓輔,久保田祐貴,Uwe Stuhr,岩佐和晃,山田和芳
  • Organizer: 日本物理学会秋季大会
  • Place of Presentation: 富山大学
  • Year and Date: 2011-09-23
• [Presentation] Molecular spin and orbital excitations in frustrated spinel-type oxides (2011)
  • Author(s): K. Tomiyasu
  • Organizer: The International Workshop on Neutron Applications on Strongly Correlated Electron Systems 2011
  • Place of Presentation: Tokai (Japan)
  • Year and Date: 2011-02-23
• [Presentation] 金属スピンフラストレート系Mn_3Ptの単結晶中性子非弾性散乱研究 (2010)
  • Author(s): 富安啓輔
  • Organizer: 第6回トピカルミーティング「フラストレーションと量子輸送」
  • Place of Presentation: 宮島
  • Year and Date: 2010-10-16
• [Remarks]
  • URL: http://calaf.phys.tohoku.ac.jp/index-j.html