论文标题
\ textit {ab intib}在高压下FEPS $ _3 $的磁性结构过渡的研究
An \textit{ab initio} study of magnetic structure transitions of FePS$_3$ under high pressure
论文作者
论文摘要
最近的实验工作表明，FEPS $ _3 $经历了从$ C2/m $（$β\ sim107^{\ circ} $）到$ C2/m $（$β\ sim90^{\ circ} $ 6 $ gpa，然后从$ 6 $ GPA到$ p \ bar $ p \ bar $ $ $ gp， $ k =（01 \ frac {1} {2}）$ to $ k =（010）$ at $ 2 $ gpa，以及与绝缘子 - 金属过渡的短距离磁性顺序。通过在$ ab \ intio $计算中保存磁点基团，我们报告以下内容：（1）我们成功地将第一个磁性结构转换在$ 1.2 $ GPA下重现，并简要讨论了Hubbard U参数对此过渡的影响。这种等值过渡会导致布里鲁因区域从以碱基为中心的单斜晶变为原始单斜晶，而辅助带隙则变为直接带隙过渡。 （2）在相邻层移动之前，通过$ [001] $轴的$ 0.5^\ circ $旋转。 （3）预计相邻层之间的变化是$ 10.0 $ GPA，并将能量顺序逆转$ d_ {x^2-y^2} $和$ d_ {xy} $之间。 （4）在绝缘体金属过渡中，Fe-S键长度突然降低至$ 2.20 $Å\。我们的工作显示了磁性结构对称性在压力诱导的磁系统相变的重要性。
Recent experimental work shows that FePS$_3$ undergoes phase transitions from $C2/m$ ($β\sim107^{\circ}$) to $C2/m$ ($β\sim90^{\circ}$) at $6$ GPa and then to metallic $P\bar{3}1m$ at $14$ GPa, with the magnetic ordering wave vector turning from $k=(01\frac{1}{2})$ to $k=(010)$ at $2$ GPa and to short-range magnetic order accompanying the insulator-metal transition. By preserving the magnetic point groups in $ab \ initio$ calculations we report the following: (1) We successfully reproduce the first magnetic structure transition at $1.2$ GPa and briefly discuss the influence of the Hubbard U parameter on this transition. This isostructural transition causes a change of the Brillouin zone from base-centered monoclinic to primitive monoclinic, and an indrect band gap to direct band gap transition. (2) There is a rotation of the Fe-S octahedron about $0.5^\circ$ through the $[001]$ axis before the neighboring layers shift. (3) The shift between neighboring layers is predicted to occur at $10.0$ GPa and reverses the energy order between $d_{x^2-y^2}$ and $d_{xy}$. (4) A sudden decrease of Fe-S bond length to $2.20$ Å\ accompanies the vanishing of magnetic moment in the insulator-metal transition. Our work shows the importance of symmetries of magnetic structures in pressure-induced phase transition of magnetic systems.
