Lattice Distortions and Magnetic Interactions in Single-Layer VOCl

Abstract

Atomically thin layers exfoliated from magnetic van der Waals layered materials are currently of high interest in solid state physics. VOCl is a quasi-two-dimensional layered antiferromagnet which was recently synthesized in monolayer form. Previous theoretical studies have assumed the high-temperature orthorhombic lattice symmetry also in the low temperature range, where the bulk system is known to be monoclinic due to a strong magnetoelastic coupling. We demonstrate from \textit{ab-initio} calulations that this monoclinic distortion is prevalent also in monolayers, which is in line with recent experimental indications of monoclinic symmetry. Our calculations also show that competing ferromagnetic and antiferromagnetic interactions give rise a frustrated two-fold magnetic superstructure where higher-order magnetic interactions play a key role to stabilize the observed magnetic ground state.

References in corpus (10)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Graphene Spintronics
• Van der Waals heterostructures for spintronics and opto-spintronics
• Hubbard U and Hund's Exchange J in Transition Metal Oxides: Screening vs. Localization Trends from Constrained Random Phase Approximation
• Pervasive beyond room-temperature ferromagnetism in a doped van der Waals magnet: Ni doped Fe${}_5$GeTe${}_2$ with $T_{\text{C}}$ up to 478 K
• Strong Magneto-elastic coupling in VOCl: Neutron and synchrotron powder x-ray diffraction study
• Electronic structure of the two-dimensional Heisenberg antiferromagnet VOCl: a multi-orbital Mott insulator
• Spin-lattice couplings in two-dimensional CrI${}_3$ from first-principles study
• Hund's physics and the magnetic ground state of CrOX (X = Cl, Br)