Nature of magnetism in Ca3Co2O6 -: art. no. 186401

被引：144

作者：

Wu, H ^{[1
]}

Haverkort, MW ^{[1
]}

Hu, Z ^{[1
]}

Khomskii, DI ^{[1
]}

Tjeng, LH ^{[1
]}

机构：

[1] Univ Cologne, Inst Phys 2, D-50937 Cologne, Germany

来源：

PHYSICAL REVIEW LETTERS | 2005年 / 95卷 / 18期

关键词：

D O I：

10.1103/PhysRevLett.95.186401

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We find using local spin density approximation+Hubbard U band structure calculations that the novel one-dimensional cobaltate Ca3Co2O6 is not a ferromagnetic half-metal but a Mott insulator. Both the octahedral and the trigonal Co ions are formally trivalent, with the octahedral being in the low-spin and the trigonal in the high-spin state. The inclusion of the spin-orbit coupling leads to the occupation of the minority-spin d(2) orbital for the unusually coordinated trigonal Co, producing a giant orbital moment (1.57 mu(B)). It also results in an anomalously large magnetocrystalline anisotropy (of order 70 meV), elucidating why the magnetism is highly Ising-like. The role of the oxygen holes, carrying an induced magnetic moment of 0.13 mu(B) per oxygen, for the exchange interactions is discussed.

引用

收藏

页数：4

相关论文

共 28 条

[1] Magnetic properties of the one-dimensional Ca3Co2O6 [J].

Aasland, S ;

Fjellvag, H ;

Hauback, B .

SOLID STATE COMMUNICATIONS, 1997, 101 (03) :187-192

[2] BAND THEORY AND MOTT INSULATORS - HUBBARD-U INSTEAD OF STONER-I [J].

ANISIMOV, VI ;

ZAANEN, J ;

ANDERSEN, OK .

PHYSICAL REVIEW B, 1991, 44 (03) :943-954

[3] Analysis of the uniaxial magnetic properties of high-spin d6 ions at trigonal prism and linear two-coordinate sites:: Uniaxial magnetic properties of Ca3Co2O6 and Fe[C(SiMe3)3]2 [J].

Dai, DD ;

Whangbo, MH .

INORGANIC CHEMISTRY, 2005, 44 (12) :4407-4414

[4] Possible path to a new class of ferromagnetic and half-metallic ferromagnetic materials [J].

Elfimov, IS ;

Yunoki, S ;

Sawatzky, GA .

PHYSICAL REVIEW LETTERS, 2002, 89 (21)

[5] Extended moment formation and magnetic ordering in the trigonal chain compound Ca3Co2O6 [J].

Eyert, V ;

Laschinger, C ;

Kopp, T ;

Frésard, R .

CHEMICAL PHYSICS LETTERS, 2004, 385 (3-4) :249-254

[6] Crystal structure and possible charge ordering in one-dimensional Ca3Co2O6 [J].

Fjellvag, H ;

Gulbrandsen, E ;

Aasland, S ;

Olsen, A ;

Hauback, BC .

JOURNAL OF SOLID STATE CHEMISTRY, 1996, 124 (01) :190-194

[7] Chromium site selective substitution in Ca3Co2O6:: Influence on the magnetic properties of an Ising-like triangular lattice -: art. no. 094418 [J].

Flahaut, D ;

Maignan, A ;

Hébert, S ;

Martin, C ;

Retoux, R ;

Hardy, V .

PHYSICAL REVIEW B, 2004, 70 (09) :094418-1

[8] Origin of magnetic interactions in Ca3Co2O6 -: art. no. 140405 [J].

Frésard, R ;

Laschinger, C ;

Kopp, T ;

Eyert, V .

PHYSICAL REVIEW B, 2004, 69 (14) :140405-1

[9]

Goodenough J. B., 1963, MAGNETISM CHEM BOND

[10] Magnetic quantum tunneling in Ca3Co2O6 studied by ac susceptibility:: Temperature and magnetic-field dependence of the spin-relaxation time -: art. no. 214439 [J].

Hardy, V ;

Flahaut, D ;

Lees, MR ;

Petrenko, OA .

PHYSICAL REVIEW B, 2004, 70 (21) :1-7