Magnetic phase transition of the perovskite-type Ti oxides

被引：25

作者：

Mochizuki, M ^{[1
]}

Imada, M ^{[1
]}

机构：

[1] Univ Tokyo, Inst Solid State Phys, Kashiwa, Chiba 2778581, Japan

来源：

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN | 2000年 / 69卷 / 07期

关键词：

perovskite-type Ti oxides; GdFeO3-type distortion; d-level degeneracy; orbital ordering; second-order perturbation theory; A-type antiferromagnetism; Mermin and Wagner's theorem;

D O I：

10.1143/JPSJ.69.1982

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The properties and mechanism of the magnetic phase transition of the perovskite-type Ti oxides, which is driven by the Ti-O-Ti bond angle distortion. are studied theoretically using the effective spin and pseudo-spin Hamiltonian with strong Coulomb repulsion. It is shown that the A-type antiferromagnetic (AFM(A)) to ferromagnetic (FM) phase transition occurs as the Ti-O-Ti bond angle is decreased. Through this phase transition, the orbital state is hardly changed so that the spin-exchange coupling along the c-axis changes nearly continuously from positive to negative and is approximately zero at the phase boundary. The resultant strong two-dimensionality in the spin coupling causes rapid suppression of the critical temperature, as observed experimentally.

引用

页码：1982 / 1985

页数：4

共 21 条

[11] Transport and magnetic properties of a Mott-Hubbard system whose bandwidth and band filling are both controllable: R1-xCaxTiO3+y/2 [J].

Katsufuji, T ;

Taguchi, Y ;

Tokura, Y .

PHYSICAL REVIEW B, 1997, 56 (16) :10145-10153

[12] ORBITAL AND MAGNETIC STRUCTURE OF 2-DIMENSIONAL FERROMAGNETS WITH JAHN-TELLER IONS [J].

KHOMSKII, DI ;

KUGEL, KI .

SOLID STATE COMMUNICATIONS, 1973, 13 (07) :763-766

[13]

KUGEL KI, 1973, ZH EKSP TEOR FIZ+, V64, P1429

[14] The Jahn-Teller effect and magnetism: transition metal compounds [J].

KUGEL, KI ;

KHOMSKII, DI .

USPEKHI FIZICHESKIKH NAUK, 1982, 136 (04) :621-664

[15]

KUGEL KI, 1972, ZH EKSP TEOR FIZ, V15, P629

[16] ABSENCE OF FERROMAGNETISM OR ANTIFERROMAGNETISM IN ONE- OR 2-DIMENSIONAL ISOTROPIC HEISENBERG MODELS [J].

MERMIN, ND ;

WAGNER, H .

PHYSICAL REVIEW LETTERS, 1966, 17 (22) :1133-&

[17] UNRESTRICTED HARTREE-FOCK STUDY OF TRANSITION-METAL OXIDES - SPIN AND ORBITAL ORDERING IN PEROVSKITE-TYPE LATTICE [J].

MIZOKAWA, T ;

FUJIMORI, A .

PHYSICAL REVIEW B, 1995, 51 (18) :12880-12883

[18] Electronic structure and orbital ordering in perovskite-type 3d transition-metal oxides studied by Hartree-Fock band-structure calculations [J].

Mizokawa, T ;

Fujimori, A .

PHYSICAL REVIEW B, 1996, 54 (08) :5368-5380

[19] OPTICAL-SPECTRA IN (LA,Y)TIO3 - VARIATION OF MOTT-HUBBARD GAP FEATURES WITH CHANGE OF ELECTRON CORRELATION AND BAND FILLING [J].

OKIMOTO, Y ;

KATSUFUJI, T ;

OKADA, Y ;

ARIMA, T ;

TOKURA, Y .

PHYSICAL REVIEW B, 1995, 51 (15) :9581-9588

[20] SYSTEMATIC VARIATION OF THE ELECTRONIC-STRUCTURE OF 3D TRANSITION-METAL COMPOUNDS [J].

SAITOH, T ;

BOCQUET, AE ;

MIZOKAWA, T ;

FUJIMORI, A .

PHYSICAL REVIEW B, 1995, 52 (11) :7934-7938

← 1 2 3 →