Density Functional Investigation of the Antiferromagnetic Ordering, Spin Orientation, and Ferroelectric Polarization of Rare-Earth Iron Borate TbFe3(BO3)4

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• 作者：Changhoon Lee ; Jinhee Kang ; Kee Hag Lee ; Myung-Hwan Whangbo
• 刊名：Chemistry of Materials
• 出版年：2009
• 出版时间：June 23, 2009
• 年：2009
• 卷：21
• 期：12
• 页码：2534-2539
• 全文大小：279K
• 年卷期：v.21,no.12(June 23, 2009)
• ISSN：1520-5002

文摘

First-principles density functional calculations were carried out to examine the electronic and magnetic properties of rare-earth iron borate TbFe₃(BO₃)₄. The spin exchange interactions between the Fe³⁺ (d⁵, S = 5/2) ions and the preferred orientation of the Tb³⁺ (f⁸) spins were evaluated, and the ferroelectric polarization of TbFe₃(BO₃)₄ was calculated. In agreement with experiment, our calculations predict that the spin exchange between the Fe³⁺ spins is ferromagnetic within each //ab sheet of Fe³⁺ ions but antiferromagnetic between adjacent //ab sheets of Fe³⁺ ions, whereas the spin exchange between the Fe³⁺ and Tb³⁺ ions within each //ab sheet of Fe³⁺ and Tb³⁺ ions is antiferromagnetic. The Tb³⁺ (f⁸) ions is found to possess an electron configuration responsible for uniaxial magnetism, hence orienting the Tb³⁺ spins along the c-direction and leading to the highly anisotropic magnetic susceptibility. The ferroelectric polarization of TbFe₃(BO₃)₄ is largely due to the absence of inversion symmetry of the crystal structure and is weakly affected by its magnetic structure.