Optical-spectroscopic detection of spin-exchange interaction pyrochlore molybdates

被引：20

作者：

Kim, MW

Lee, YS

Noh, TW ^{[1
]}

Yu, JJ

Moritomo, Y

机构：

[1] Seoul Natl Univ, ReCOE, Seoul 151747, South Korea

[2] Seoul Natl Univ, Sch Phys, Seoul 151747, South Korea

[3] Seoul Natl Univ, CSCMR, Seoul 151747, South Korea

[4] Nagoya Univ, Dept Appl Phys, Nagoya, Aichi 4648603, Japan

来源：

PHYSICAL REVIEW LETTERS | 2004年 / 92卷 / 02期

关键词：

D O I：

10.1103/PhysRevLett.92.027202

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Optical spectroscopy was used to determine nearest-neighbor spin correlations in pyrochlore molybdates R2Mo2O7 (R=Y, Sm, and Nd), which exhibit ferromagnetic metal to spin-glass insulator transition as the R ion size decreases. Using an analysis based on the orbitally degenerate Hubbard model, we could estimate important physical parameters, such as the effective on-site Coulomb energy U-eff and the Hund rule exchange coupling J(H). We demonstrated experimentally and theoretically that the effective superexchange interaction between the Mo ions depends on J(H)/U-eff, which determines the phase boundary of the magnetic ground states.

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页数：4

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