Size effects in multiferroic BiFeO 3 nanodots: A first-principles-based study
Size effects in multiferroic BiFeO 3 nanodots: A first-principles-based study
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DOI：
10.1103/physrevb.82.113403
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发表时间：
2010-09
影响因子：
3.7
通讯作者：
W. Ren;L. Bellaiche
中科院分区：
文献类型：
--
作者：
W. Ren;L. Bellaiche
提出了一种有效的哈密顿方法来研究${\text{BiFeO}}{3}$纳米点在类短路电边界条件下的结构和磁性.发现了各种惊人的效果。例子包括（a）涉及磁转变温度和电转变温度的点尺寸的倒数的标度律;（B）通过尺寸效应洗出存在于本体中的一些结构相;（c）通过玩弄尺寸和电边界条件来定制Neel温度和居里温度之间的差异的可能性;和（d）1.6nm量级的通用临界厚度，低于该厚度点不具有电和磁偶极子以及氧八面体倾斜的任何长程有序。
An effective Hamiltonian scheme is developed to investigate structural and magnetic properties of ${\text{BiFeO}}_{3}$ nanodots under short-circuit-like electrical boundary conditions. Various striking effects are discovered. Examples include (a) scaling laws involving the inverse of the dots' size for the magnetic and electric transition temperatures; (b) the washing out of some structural phases present in the bulk via size effects; (c) the possibility of tailoring the difference between the Neel and Curie temperatures, by playing with the size and electrical boundary conditions; and (d) an universal critical thickness of the order of 1.6 nm below which the dots do not possess any long-range ordering for the electrical and magnetic dipoles, as well as, for the oxygen octahedral tiltings.