Antiferromagnetic superexchange via 3d states of titanium in EuTiO3 as seen from hybrid Hartree-Fock density functional calculations
Antiferromagnetic superexchange via 3d states of titanium in EuTiO3 as seen from hybrid Hartree-Fock density functional calculations
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DOI：
10.1103/physrevb.83.214421
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发表时间：
2011-06-15
影响因子：
3.7
通讯作者：
Tanaka, Isao
中科院分区：
文献类型：
--
作者：
Akamatsu, Hirofumi;Kumagai, Yu;Tanaka, Isao
通过基于混合 Hartree-Fock 密度泛函方法的第一性原理计算，提出了 Eu2+ 4f 自旋之间通过非磁性 Ti4+ 离子 3d 态的超交换机制来解释 EuTiO3 中的 G 型反铁磁性。该机制得到了相关 Eu2+ 基钙钛矿氧化物的系统计算的支持。在EuTiO3中，反铁磁超级交换和通过Eu 5d态的间接铁磁交换之间的竞争导致反铁磁相和铁磁相之间的微妙平衡。涉及 Ti 3d 态的超交换机制暗示了 EuTiO3 中强自旋晶格耦合的微观起源。
A superexchange mechanism between Eu2+ 4f spins via the 3d states of nonmagnetic Ti4+ ions is proposed through first-principles calculations based on a hybrid Hartree-Fock density functional approach to explain G-type antiferromagnetism in EuTiO3. This mechanism is supported by systematic calculations for related Eu2+-based perovskite oxides. In EuTiO3, the competition between the antiferromagnetic superexchange and an indirect ferromagnetic exchange via the Eu 5d states leads to a delicate balance between antiferromagnetic and ferromagnetic phases. The superexchange mechanism involving the Ti 3d states hints at the microscopic origin of the strong spin-lattice coupling in EuTiO3.