Project/Area Number  08640461 
Research Category 
GrantinAid for Scientific Research (C)

Section  一般 
Research Field 
固体物性II(磁性・金属・低温)

Research Institution  HIROSHIMA UNIVERSITY 
Principal Investigator 
JO Takeo Faculty of Science, HIROSHIM UNIVERSITY Professor, 理学部, 教授 (20093487)

CoInvestigator(Kenkyūbuntansha) 
TANAKA Arata Faculty of Science, HIROSHIMA UNIVERSITY Research Associate, 理学部, 助手 (70253052)
OGUCHI Tamio Faculty of Science, HIROSHIMA UNIVERSITY Professor, 理学部, 教授 (90253054)

Project Fiscal Year 
1996 – 1997

Project Status 
Completed(Fiscal Year 1997)

Budget Amount *help 
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1997 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1996 : ¥1,200,000 (Direct Cost : ¥1,200,000)

Keywords  Actinide / Uranium compound / Orbital magnetic moment / HartreeFock approximation / LDA / Magnetic circular dichroism / FeO / CoO / アクチナイド / ウラン化合物 / 軌道磁気モーメント / ハートレー・フォック近似 / 磁気円二色性 / ハートレー・フォックス近似 / アンダーソン模型 / 配置間相互作用 
Research Abstract 
We have extended the HartreeFock (HF) calculation of the 5f orbital and spin moments (M_<orb> and M_<spin>, respectively) to NaCltype ferromagnet USe and UTe in addition to US on the basis of an extended Hubbard model, where the 5f, 6d and 7s orbits of U atom and the 3s, 3p ones of S atom are included and the intraatomic multipole 5f5f interaction is taken into account. We determined the parameters of transfer integral by using the LDAFLAPW calculation in the paramagnetic state without spinorbit interaction. The Slater integral except F^0 representing the 5f5f interaction is determined by HF calculation or analyzes of highenergy spectroscopies. We determine F^0 so as to obtain an agreement between the calculation and the experiment for the total 5f moment. The obtained M_<spin> and M_<orb > are antiparallel with each other and the ratio M_<orb>/M_<2spin> is  2.1, which is in agreement with experimental results. We determine selfconsistently the expectation values of 14 number operators and 91 (= _<14>C_2) offdiagonal operators of the 5f state. The includion of the latter is found to be important to estimate the magnitude of spin dipole. We have also performed the HF calculation of M_<spin> and M_<orb> of the secondtype antiferromagnets CoO and FeO with taking into account the full 3d orbits and multipole interaction and the O 2p orbits. The calculated M_<orb> of both systems is found to be  1mu_B, which has been pointed out in a singleion model. For CoO,we found as a HF solution a noncollinear magnetic structure in addition to a collinear structure, both of which are suggested as candidates by the neutron diffraction.
