Monte Carlo study of phase transitions and magnetic properties of LaMnO3: Heisenberg model
Monte Carlo study of phase transitions and magnetic properties of LaMnO3: Heisenberg model
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DOI：
10.1016/j.physa.2012.03.003
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发表时间：
2012-08
影响因子：
3.3
通讯作者：
S. Naji;A. Benyoussef;A. Kenz;H. Ez‐zahraouy;M. Loulidi
中科院分区：
文献类型：
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作者：
S. Naji;A. Benyoussef;A. Kenz;H. Ez‐zahraouy;M. Loulidi
在从头计算(FPLO)和蒙特卡罗模拟(MCS)的基础上，采用Heisenberg模型研究了块体钙钛矿LaMnO_3的相图和磁性。在标量相对论方案中用从头算方法计算表明，稳定相是反铁磁的A型，它对应于锰离子在基面(a，b)中的铁磁顺序和这些离子之间沿c轴的反铁磁顺序。利用全四分量相对论方案，计算了磁体的各向异性能和各向异性常数，发现(010)b轴是有利的磁方向。在蒙特卡罗模拟框架下得到了相变温度和临界指数。从从头算出发，推导了海森堡模型的磁各向异性和交换耦合。通过使用蒙特卡罗模拟，它们导致了与实验转变温度的定量一致。
On the basis of ab initio calculations (FPLO) and Monte Carlo Simulations (MCS) the phase diagrams and magnetic properties of the bulk perovskite LaMnO3have been studied, using the Heisenberg model. It is shown, using ab initio calculations in the scalar relativistic scheme, that the stable phase is the antiferromagnetic A-type, which corresponds to ferromagnetic order of the manganese ions in the basal planes (a,b) and antiferromagnetic order of these ions between these planes along the c axis. Using the full four-component relativistic scheme, in order to calculate the magnetic anisotropy energy and constants, it is found that the favorable magnetic direction is the (010) b axis. The transition temperatures and the critical exponents are obtained in the framework of Monte Carlo simulations. The magnetic anisotropy and the exchange couplings of the Heisenberg model are deduced from ab initio calculations. They lead, by using Monte Carlo simulations, to a quantitative agreement with the experimental transition temperatures.