磁制冷材料LaFe_(11.5)Si_(1.5)基合金成分与磁相变温度关系的高通量计算

High-throughput computation on relationship between composition and magnetic phase transition temperature of LaFe_(11.5)Si_(1.5)-based magnetic refrigeration materials

获得具有不同磁相变温度的La(Fe,Si)_(13)基合金对拓宽磁制冷工作温区具有重要意义.借助第一性原理模拟软件AMS-BAND模块并结合平均场理论对LaFe_(11.5)Si_(1.5)基磁制冷合金的磁相变温度进行了高通量计算.研究了Mn,Co,Ni,Al和Fe缺位掺杂对LaFe_(11.5)Si_(1.5)基合金体系相变温度的影响,得到了成分与磁相变温度的关系图.利用高通量第一性原理计算可以有效地降低研究成本,提高科研效率,并能够对后续实验选取具有合适磁相变温度的磁制冷材料提供技术支持.

La(Fe,Si)_(13)-based alloys have attracted more and more attention,for they exhibit giant magnetocaloric effects.In order to broaden their magnetic refrigeration temperatureranges,achieving a series of La(Fe,Si)_(13)-based alloys with different magnetic phase transition temperatures is of great significance.Unlike the traditional research method,in this paper,a high-throughput first-principles computation is performed to estimate the magnetic phase transition temperature of the LaFe_(11.5)Si_(1.5)-based alloy by employing AMS-BAND software and the mean field theory.We investigate the effects of doping Mn,Co,Ni,Al atoms and Fe-vacancies on the magnetic phase transition temperature of LaFe_(11.5)Si_(1.5)-based alloy,and give the phase diagrams between the composition and magnetic phase transition temperature.The calculated results demonstrate that the magnetic phase transition temperature of the LaFe_(11.5)Si_(1.5)-based alloy increases with the increase of Co and Ni content.However,it shows an opposite result when Mn atom is doped.As for the LaFe_(11.5)Si_(1.5)-based alloy with the Fevacancies,the research results indicate that the absence of Fe atoms will reduce the magnetic phase transition temperature.Furthermore,when Mn,Co,Ni and Al atoms are doped in the alloys with Fe-vacancies,the variation tendency of the magnetic phase transition temperature with the change of the doping content is similar to that without the Fe-vacancies.Some estimated results are compared with the experimental or reported results,showing that they are in good agreement with each other.The PDOS and the magnetic moments of Fe atoms in the Mn,Co,Ni,Al-doped LaFe_(11.5)Si_(1.5)-based alloys are calculated,in which only the doping of Mn atoms can increase the magnetic moments of Fe atoms.Using the method of high-throughput first-principles calculation can effectively reduce the research cost and improve the working efficiency.In addition,it can provide technical support for the experimental selection of magnetocaloric materials with appropriate magnetic phase transition temperatures.