Origin of ferroelectricity in the multiferroic barium fluorides BaMF4:: A first principles study
Origin of ferroelectricity in the multiferroic barium fluorides BaMF4:: A first principles study
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DOI：
10.1103/physrevb.74.024102
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发表时间：
2006-07-01
影响因子：
3.7
通讯作者：
Spaldin, Nicola A.
中科院分区：
文献类型：
--
作者：
Ederer, Claude;Spaldin, Nicola A.
我们提出了第一性原理研究的一系列多铁性氟化钡的组成BaMF 4，其中M是Mn，Fe，Co，或Ni。我们讨论的结构，电子和磁性的趋势，我们表明，在这些系统中的铁电性的结果冻结在一个单一的不稳定的极性声子模式。与标准钙钛矿铁电体的情况相反，这种结构畸变不伴随阳离子和阴离子之间的电荷转移。因此，在多铁性氟化钡中的铁电不稳定性仅仅是由于尺寸效应和底层晶体结构的特殊几何约束而产生的。
We present a first-principles study of the series of multiferroic barium fluorides with the composition BaMF4, where M is Mn, Fe, Co, or Ni. We discuss trends in the structural, electronic, and magnetic properties, and we show that the ferroelectricity in these systems results from the freezing in of a single unstable polar phonon mode. In contrast to the case of the standard perovskite ferroelectrics, this structural distortion is not accompanied by charge transfer between cations and anions. Thus, the ferroelectric instability in the multiferroic barium fluorides arises solely due to size effects and the special geometrical constraints of the underlying crystal structure.