2000 Fiscal Year Annual Research Report

軌道縮退系の電子構造

Research Project

Project/Area Number	11220203
Research Institution	Tohoku University
Principal Investigator	青木晴善東北大学, 極低温科学センター, 教授 (60302246)
Co-Investigator(Kenkyū-buntansha)	高木滋東北大学, 大学院・理学研究科, 助教授 (20154750) 高橋隆東北大学, 大学院・理学研究科, 助教授 (00142919) 國井暁東北大学, 大学院・理学研究科, 助教授 (10004368) 中村慎太郎東北大学, 極低温科学センター, 助手 (20292310) 落合明東北大学, 極低温科学センター, 助教授 (90183772)
Keywords	軌道秩序 / 高温強磁性 / 四重極転移 / CaB_6 / CeB_6 / RB_2C_2
Research Abstract	1.高温強磁性: 電子スピン共鳴により、比較的大きな磁気モーメントがミクロンオーダーの表面層に局在し、非常に強い磁気異方性のためにその面内に束縛されていることを示した。また、強磁性の出現はCa、B、Laの組成のある領域において起こりやすいが、組成と磁気的な性質とは直接対応がつかなことを明らかにした。単結晶試料では磁化に異方性が存在し、温度サイクルまたは実験の繰り返しによって異方性の消失とともに、磁化の減少が起こることを見い出した。 2.CeB_6および四重極秩序を示す物質: (i)新たにDyB_6のフォノン分散関係を求め、LaB_6及びCeB_6の分散関係等を総合した解析からRB_6のフォノンの統一的な構造が明らかとなった。また、PrB_6に加え、TbB_6でも3次の帯磁率が観測され、四重極子秩序をするCeB_6やDyB_6以外のRB_6においても物性を支配している可能性の大きいことを明らかにした。 (ii)HoB_2C_2における共鳴X線散乱の実験により,四重極子秩序および磁気秩序にともなう秩序変数の温度変化を明らかにした。 (iii)一軸性圧力下のdHvA効果測定装置の開発を行い、CeB_6の軸性圧力に伴う磁気相図の変化を調べるとともに,dHvA効果によりフェルミ面の変化、有効質量の変化の測定に成功した。 3.ウラン化合物: 高分解能角度分解光電子分光によりUPd_3において、U5f電子はフェルミ面にはほとんど寄与していない事、また、UX_c(X_c=S,Se,Te)において、交換分裂による電子構造の変化を観測し、UX_cの磁性が遍歴強磁性として理解されることを明らかにした。また、USb_2では幅の狭いU5fバンドが「重い」フェルミ面を形成していることを見出した。 4.Yb_4As_3および関連物質: Yb_4As_3において共鳴X線散乱の実験により、電荷秩序の直接証拠である禁制反射を見いだした。Sm_4Bi_3でのSdH効果の測定に初めて成功した。

Research Products
(42 results)

All Other

All Publications (42 results)

[Publications] T.Iwasaki, et al.: "Bulk and surface electronic structures of CePdX (X=As, Sb) studied by 3d-4f resonance photoemission"Phys.Rev.B. 61. 4621-4628 (2000)
[Publications] Y.Nemoto, et al.: "Ultrasonic study of the charge fluctuation compound Sm_3Te_4"Phys.Rev.B. 61. 12050-12058 (2000)
[Publications] H.Kumigashira, et al.: "High-resolution angle-resolved photoemission study of USb : Dual caharacter of 5f electrons"Phys.Rev.B. 61. 15707-15713 (2000)
[Publications] Y.Nemoto, et al.: "Charge fluctuation in Sm_3Te_4"Physica B. 281&282. 136-138 (2000)
[Publications] S.Suga, et al.: "Electronic states of Sm_4As_3 and Sm_4Bi_3 studied with photoemission spectroscopy"Physica B. 281&282. 158-160 (2000)
[Publications] M.Lang, et al.: "Evidence for magnons and solitons in the one-dimensional S=1/2 antiferromagnet Yb_4As_3"Physica B. 281&282. 458-459 (2000)
[Publications] S.Takagi, et al.: "NMR and NQR studies of Yb_4 (As_<1-x>P_x)_3 systems"Physica B. 281&282. 462-464 (2000)
[Publications] H.Aoki, et al.: "Mgnetic anisotropy in Yb_4As_3 with one-dimensional Yb^<3+> chains"Physica B. 281&282. 465-467 (2000)
[Publications] P.A.Alekseev, et al.: "Neutron Scattering study of the magnetic excitation spectra in mixed-valence ^<154>Sm_3Te_4"J.Phys. : Condens.Matter. 12. 2725-2736 (2000)
[Publications] F.Steglich, et al.: "Magnons and solitons excitations in the carrier poor, one-dimensional S=1/2 antiferromagnet Yb_4As_3"Acta Physica Polonica A. 97. 91-100 (2000)
[Publications] O.Sakai, et al.: "Local symmetry and crysatlline field effects in charge-ordered Yb_4As_3"J.Phys.Soc.Jpn.. 69. 3633-3641 (2000)
[Publications] U.Staub, et al.: "Direct observation of 1-dimensinal charge order below the first-order"metalinsulator" transition in Yb_4As_3"Europhys.Lett.. 53. 72-78 (2001)
[Publications] N.Metoki, et al.: "Neutron Scattering Studies on Heavy Fermion Superconductors"Physica B. 280. 362-367 (2000)
[Publications] T.Horino, et al.: "Quadrupolar Effect of R_3Pd_<20>Ge_6 (R=Ce,Pr,Nd)"Physica B. 281&282. 576-578 (2000)
[Publications] D.Maruta, et al.: "Evidence from 29Si NMR of the Importance of the Hybridization between 5f and Conduction Electrons in U_3Pd_<20>Si_6"Physica B. 281&282. 251-253 (2000)
[Publications] J.Kitagawa, et al.: "Third-order magnetic susceptibility and quadrupolar order parameter of Kondo-lattice compound Ce_3Pd_<20>Ge_6"J.Phys.Soc.Jpn.. 69. 883-887 (2000)
[Publications] J.M.Mignot, et al.: "Neutron diffraction study of quadrupolar and magnetic order in TmTe"Physica B. 281&282. 470-476 (2000)
[Publications] P.Link, et al.: "Antiferromagnetism and quadrupolar order in TmTe : a low-temperature neutron-diffraction study"Physica B. 281&282. 569-570 (2000)
[Publications] T.Tomita, et al.: "Antiferro-quadrupolar ordering in TmTe under high magnetic fields and high pressures"Physica B. 281&282. 574-575 (2000)
[Publications] M.Nakayama, et al.: "Crystal Field Effect in R_3Pd_<20>Ge_6 (R=Pr and Nd)"Physica B. 281&282. 152-154 (2000)
[Publications] N.Kimura, et al.: "Fermi Surace Property of UPt_3 Studied by de Hass-van Alphen and Magnetoresistance Experiments"Physica B. 281&282. 710-715 (2000)
[Publications] N.Tateiwa, et al.: "Low Temperature Physical Properties of U_3Pd_<20>Si_6"Physica B. 281&282. 254-255 (2000)
[Publications] N.Tateiwa, et al.: "Transport, Thermal and Magnetic Properties of the New Ternary Compound U_3Pd_<20>Si_6 : Posiibility of a New Localized 5f Electrons System"J.Phys.Soc.Jpn.. 69. 1517-1520 (2000)
[Publications] T.Terashima, et al.: "Ferromagnetism vs Paramagnetism and False Quantum Oscillations in Lanthanum-Doped CaB_6"J.Phys.Soc.Jpn.. 69. 2423-2426 (2000)
[Publications] H.Kumigashira, et al.: "High-resolution angle-resolved photoemission study of USb ; dual character of 5f electrons"Phys.Rev.B. 61. 15707-15713 (2000)
[Publications] H.Kumigashira, et al.: "Pseudogap formation in Kondo insulators CeRhSb and CeRhAs studied by ultrahigh-resolution photoemission spectroscopy"Pysica B. 281&282. 284-285 (2000)
[Publications] M.Magnuson, et al.: "Electronic-structure investigation of CeB_6 by means of soft-x-ray scattering ;"Phys.Rev.B. (印刷中).
[Publications] S.Nakamura, et al.: "Low-temperature specific heat of Ce_xLa_<1-x>B_6"Pysica B. 281&282. 559-560 (2000)
[Publications] T.Goto, et al.: "Quadrupolar effect of HoB_6 and DyB_6"Pysica B. 281&282. 586-587 (2000)
[Publications] S.Nakamura, et al.: "Screening effect on the multipole moments in the Kondo system Ce_xLa_<1-x>B_6"Phy.Rev.B. 61. 15203-15212 (2000)
[Publications] S.Kobayashi, et al.: "Transport Properties in Phase IV of Ce_xLa_<1-x>B_6"J.Phys.Soc.Jpn.. 69. 926-936 (2000)
[Publications] K.Magishi, et al.: "^<11>B NMR in the antiferromagnetic phases of CeB_6"Physica B. 281&282. 548-549 (2000)
[Publications] Y.Uwatoko, et al.: "Effect of pressure on the antiferro-quadrupolar transition of CeB_6"Physica B. 281&282. 555-556 (2000)
[Publications] T.Takikawa, et al.: "Magnetic properties of Ce_<0.75>La_<0.25>B_6 under uniaxial stress"Physica B. 281&282. 561-562 (2000)
[Publications] N.E.Sluchanko, et al.: "The origin of the fast valence fluctuations in SmB_6"Pysica B. 284&288. 1355-1356 (2000)
[Publications] S.Kunii, et al.: "Phonon structure and specific heat analyses of rare-earth hexaborides"J.Solid State Chemistry. 154. 275-279 (2000)
[Publications] H.Onodera, et al.: "^<167>Dy Mossbauer Spectroscopic Study of the Ferroquadrupolar Ordering Compound DyB_6"J.Phys.Soc.Jpn.. 69. 1100-1104 (2000)
[Publications] N.E.Sluchanko, et al.: "Intra-gap states in SmB_6"Phys.Rev.B. 61. 9906-9909 (2000)
[Publications] S.Nakamura, et al.: "Screening effect on the multipole moments in the Kondo system Ce_xLa_<1-x>B_6"Phys.Rev.B. 61. 15203-15212 (2000)
[Publications] S.Kobayashi, et al.: "Transport Properties in Phase IV of Ce_xLa_<1-x>B_6"J.Phys.Soc.Jpn.. 69. 926 (2000)
[Publications] S.Tsuji, et al.: "NMR Study of NdB_6"J.Phys.Soc.Jpn.. 69. 1974 (2000)
[Publications] S.Kunii: "Surface-layer ferromagnetism and strong surface-anisotropy in Ca_<1-x>La_xB_6 (x=0.005) evidenced by ferromagnetic resonance"J.Phys.Soc.Jpn.. 69. 3789-3791 (2000)

2000 Fiscal Year Annual Research Report

軌道縮退系の電子構造

Principal Investigator

青木 晴善 東北大学, 極低温科学センター, 教授 (60302246)

Research Products

[Publications] T.Iwasaki, et al.: "Bulk and surface electronic structures of CePdX (X=As, Sb) studied by 3d-4f resonance photoemission"Phys.Rev.B. 61. 4621-4628 (2000)

[Publications] Y.Nemoto, et al.: "Ultrasonic study of the charge fluctuation compound Sm_3Te_4"Phys.Rev.B. 61. 12050-12058 (2000)

[Publications] H.Kumigashira, et al.: "High-resolution angle-resolved photoemission study of USb : Dual caharacter of 5f electrons"Phys.Rev.B. 61. 15707-15713 (2000)

[Publications] Y.Nemoto, et al.: "Charge fluctuation in Sm_3Te_4"Physica B. 281&282. 136-138 (2000)

[Publications] S.Suga, et al.: "Electronic states of Sm_4As_3 and Sm_4Bi_3 studied with photoemission spectroscopy"Physica B. 281&282. 158-160 (2000)

[Publications] M.Lang, et al.: "Evidence for magnons and solitons in the one-dimensional S=1/2 antiferromagnet Yb_4As_3"Physica B. 281&282. 458-459 (2000)

[Publications] S.Takagi, et al.: "NMR and NQR studies of Yb_4 (As_<1-x>P_x)_3 systems"Physica B. 281&282. 462-464 (2000)

[Publications] H.Aoki, et al.: "Mgnetic anisotropy in Yb_4As_3 with one-dimensional Yb^<3+> chains"Physica B. 281&282. 465-467 (2000)

[Publications] P.A.Alekseev, et al.: "Neutron Scattering study of the magnetic excitation spectra in mixed-valence ^<154>Sm_3Te_4"J.Phys. : Condens.Matter. 12. 2725-2736 (2000)

[Publications] F.Steglich, et al.: "Magnons and solitons excitations in the carrier poor, one-dimensional S=1/2 antiferromagnet Yb_4As_3"Acta Physica Polonica A. 97. 91-100 (2000)

[Publications] O.Sakai, et al.: "Local symmetry and crysatlline field effects in charge-ordered Yb_4As_3"J.Phys.Soc.Jpn.. 69. 3633-3641 (2000)

[Publications] U.Staub, et al.: "Direct observation of 1-dimensinal charge order below the first-order"metalinsulator" transition in Yb_4As_3"Europhys.Lett.. 53. 72-78 (2001)

[Publications] N.Metoki, et al.: "Neutron Scattering Studies on Heavy Fermion Superconductors"Physica B. 280. 362-367 (2000)

[Publications] T.Horino, et al.: "Quadrupolar Effect of R_3Pd_<20>Ge_6 (R=Ce,Pr,Nd)"Physica B. 281&282. 576-578 (2000)

[Publications] D.Maruta, et al.: "Evidence from 29Si NMR of the Importance of the Hybridization between 5f and Conduction Electrons in U_3Pd_<20>Si_6"Physica B. 281&282. 251-253 (2000)

[Publications] J.Kitagawa, et al.: "Third-order magnetic susceptibility and quadrupolar order parameter of Kondo-lattice compound Ce_3Pd_<20>Ge_6"J.Phys.Soc.Jpn.. 69. 883-887 (2000)

[Publications] J.M.Mignot, et al.: "Neutron diffraction study of quadrupolar and magnetic order in TmTe"Physica B. 281&282. 470-476 (2000)

[Publications] P.Link, et al.: "Antiferromagnetism and quadrupolar order in TmTe : a low-temperature neutron-diffraction study"Physica B. 281&282. 569-570 (2000)

[Publications] T.Tomita, et al.: "Antiferro-quadrupolar ordering in TmTe under high magnetic fields and high pressures"Physica B. 281&282. 574-575 (2000)

[Publications] M.Nakayama, et al.: "Crystal Field Effect in R_3Pd_<20>Ge_6 (R=Pr and Nd)"Physica B. 281&282. 152-154 (2000)

[Publications] N.Kimura, et al.: "Fermi Surace Property of UPt_3 Studied by de Hass-van Alphen and Magnetoresistance Experiments"Physica B. 281&282. 710-715 (2000)

[Publications] N.Tateiwa, et al.: "Low Temperature Physical Properties of U_3Pd_<20>Si_6"Physica B. 281&282. 254-255 (2000)

[Publications] N.Tateiwa, et al.: "Transport, Thermal and Magnetic Properties of the New Ternary Compound U_3Pd_<20>Si_6 : Posiibility of a New Localized 5f Electrons System"J.Phys.Soc.Jpn.. 69. 1517-1520 (2000)

[Publications] T.Terashima, et al.: "Ferromagnetism vs Paramagnetism and False Quantum Oscillations in Lanthanum-Doped CaB_6"J.Phys.Soc.Jpn.. 69. 2423-2426 (2000)

[Publications] H.Kumigashira, et al.: "High-resolution angle-resolved photoemission study of USb ; dual character of 5f electrons"Phys.Rev.B. 61. 15707-15713 (2000)

[Publications] H.Kumigashira, et al.: "Pseudogap formation in Kondo insulators CeRhSb and CeRhAs studied by ultrahigh-resolution photoemission spectroscopy"Pysica B. 281&282. 284-285 (2000)

[Publications] M.Magnuson, et al.: "Electronic-structure investigation of CeB_6 by means of soft-x-ray scattering ;"Phys.Rev.B. (印刷中).

[Publications] S.Nakamura, et al.: "Low-temperature specific heat of Ce_xLa_<1-x>B_6"Pysica B. 281&282. 559-560 (2000)

[Publications] T.Goto, et al.: "Quadrupolar effect of HoB_6 and DyB_6"Pysica B. 281&282. 586-587 (2000)

[Publications] S.Nakamura, et al.: "Screening effect on the multipole moments in the Kondo system Ce_xLa_<1-x>B_6"Phy.Rev.B. 61. 15203-15212 (2000)

[Publications] S.Kobayashi, et al.: "Transport Properties in Phase IV of Ce_xLa_<1-x>B_6"J.Phys.Soc.Jpn.. 69. 926-936 (2000)

[Publications] K.Magishi, et al.: "^<11>B NMR in the antiferromagnetic phases of CeB_6"Physica B. 281&282. 548-549 (2000)

[Publications] Y.Uwatoko, et al.: "Effect of pressure on the antiferro-quadrupolar transition of CeB_6"Physica B. 281&282. 555-556 (2000)

[Publications] T.Takikawa, et al.: "Magnetic properties of Ce_<0.75>La_<0.25>B_6 under uniaxial stress"Physica B. 281&282. 561-562 (2000)

[Publications] N.E.Sluchanko, et al.: "The origin of the fast valence fluctuations in SmB_6"Pysica B. 284&288. 1355-1356 (2000)

[Publications] S.Kunii, et al.: "Phonon structure and specific heat analyses of rare-earth hexaborides"J.Solid State Chemistry. 154. 275-279 (2000)

[Publications] H.Onodera, et al.: "^<167>Dy Mossbauer Spectroscopic Study of the Ferroquadrupolar Ordering Compound DyB_6"J.Phys.Soc.Jpn.. 69. 1100-1104 (2000)

[Publications] N.E.Sluchanko, et al.: "Intra-gap states in SmB_6"Phys.Rev.B. 61. 9906-9909 (2000)

[Publications] S.Nakamura, et al.: "Screening effect on the multipole moments in the Kondo system Ce_xLa_<1-x>B_6"Phys.Rev.B. 61. 15203-15212 (2000)

[Publications] S.Kobayashi, et al.: "Transport Properties in Phase IV of Ce_xLa_<1-x>B_6"J.Phys.Soc.Jpn.. 69. 926 (2000)

[Publications] S.Tsuji, et al.: "NMR Study of NdB_6"J.Phys.Soc.Jpn.. 69. 1974 (2000)

[Publications] S.Kunii: "Surface-layer ferromagnetism and strong surface-anisotropy in Ca_<1-x>La_xB_6 (x=0.005) evidenced by ferromagnetic resonance"J.Phys.Soc.Jpn.. 69. 3789-3791 (2000)

青木晴善東北大学, 極低温科学センター, 教授 (60302246)