An \textit{ab initio} study of magnetic structure transitions of FePS${}_3$ under high pressure

Abstract

Recent experimental work shows that FePS${}_3$ undergoes phase transitions from $C2/m$ ($\beta \sim 107^{\circ }$) to $C2/m$ ($\beta \sim 90^{\circ }$) 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 $abinitio$ 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.

References in corpus (4)

• Ising-Type Magnetic Ordering in Atomically Thin FePS3
• Calculations of Hubbard U from first-principles
• Sequential structural and antiferromagnetic transitions in BaFe${}_2$Se${}_3$ under pressure
• Pressure induced collapse of magnetic order in jarosite