2006 Fiscal Year Final Research Report Summary
EVOLUTION OF F ELECTRON STATE DUE TO THE MANY BODY EFFECT ARISING FROM SPIN AND ORBITAL DEGRESS OF FREEDOM-EXPERIMENTAL STUDIES ON ALLOYS OF THE F ELECTRON COMPOUNDS
| Project/Area Number |
16340095
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Condensed matter physics II
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
AOKI Haruyoshi TOHOKU UNIVERSITY, GRADUATE SCHOOL OF SCIENCE, PROFESSOR, 大学院理学研究科, 教授 (60302246)
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| Co-Investigator(Kenkyū-buntansha) |
OCHIAI Akira TOHOKU UNIVERSITY, GRADUATE SCHOOL OF SCIENCE, ASSOCIATE PROFESSOR, 大学院理学研究科, 助教授 (90183772)
NAKAMURA Shintaro TOHOKU UNIVERSITY, INSTITUTE FOR MATERIALS RESEARCH, ASSISTANT PROFESSOR, 金属材料研究所, 助手 (20292310)
KIMURA Noriaki TOHOKU UNIVERSITY, GRADUATE SCHOOL OF SCIENCE, ASSISTANT PROFESSOR, 大学院理学研究科, 助手 (30292311)
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| Project Period (FY) |
2004 – 2006
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| Keywords | Alloy compound / felectron compound / Many body effect / dHvA effect |
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| Research Abstract |
1.We have performed the dHvA effect and resistivity measurements on the alloy compounds Ce_xLa_<1-x>B6 and Pr_xLa_<1-x>136 and have found the followings. The main Fermi surface of Ce.Lai..136 changes considerably with x and the effective mass increases almost linearly with x. The effective mass increases markedly with decreasing field but becomes nearly constant at low fields when the ground states are ordered states, while it diverges and then non-Fermi liquid behavior of the conduction electron appears when the ground state is the disordered state. The effective masses of the up and down spin conduction electrons are nearly the same when x is small but differ largely when x is large. On the other hand, the Fermi surface and the effective mass of Pr_xLa_<1-x>B_6 does not change largely with x and no anomalous behaviors of effective mass and transport properties are found.
2.For CeRu_2(Si_<1-x>Ge_x)_2 we have determined the magnetic phase diagram by magnetic measurements and also perfor
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med the dHvA effect study. We have successfully observed the dHvA effect in the samples with various x ranging from 0 to 1. From these measurements we have uncovered the relationship among the magnetic phase diagram, quantum critical point, metamagnetic transition and the electronic state, particularly localized-itinerant state of the f electron.
3.We have also observed successfully the dHvA effect in the alloy compound Pr_<1-x>La_xPb_3 as well as other strongly correlated f electron compounds.
4.We have increased the maximum pressure of the piston cylinder cell which is compatible with the dHvA effect measurements up to above 3GPa. Owing to this improvement we have clarified the electronic structure change with pressure of the pressure induced superconductor CeIn_3 and the variation of the magnetic state with pressure of the weak ferromagnet ZrZn_2 as well as the electronic and superconducting properties of the pressure induced superconductor CeRhSi_3 with no-inversion symmetry and of the pressure induced ferromagnetic superconductor UGe_2. Less
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Research Products
(52 results)
