Pressure-tuned valence transition, insulator-metal transition in van der Waals antiferromagnet <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mtext>CrPS</mml:mtext><mml:mn>3</mml:mn></mml:msub></mml:math>
Dipayan Sen, Tanusri Saha‐Dasgupta
Abstract
Motivated by the recent reports of pressure-induced engaging phenomena in van der Waals antiferromagnetic late transition metal phosphorous trisulfide compounds such as ${\mathrm{FePS}}_{3}, {\mathrm{NiPS}}_{3}$, and ${\mathrm{MnPS}}_{3}$, we explore the effect of pressure in an early-transition-metal-based compound, ${\mathrm{CrPS}}_{3}$. Our study, combining an evolutionary algorithm and first-principles calculations, establishes the existence of a pressure-induced insulator-metal transition in ${\mathrm{CrPS}}_{3}$ akin to that in ${\mathrm{FePS}}_{3}, {\mathrm{NiPS}}_{3}$, and ${\mathrm{MnPS}}_{3}$. However, while for late-transition-metal-based compounds such as ${\mathrm{FePS}}_{3}$ and ${\mathrm{MnPS}}_{3}$ the application of pressure causes a spin-state transition, in an early-transition-metal-based system it causes a valence transition, driven by the destabilization of P-P dimerization. The weakening of metal-sulfur covalency in early transition metals compared with late transition metals is found to be the origin of this contrasting behavior. The high-pressure phase is predicted to exhibit easy-axis, in-plane ferromagnetism, opening the possibility of realizing two-dimensional ferromagnetism in this class of compounds.