Abstract
Polar lacunar spinels, such as and , were proposed to host skyrmion phases under magnetic field. In this work, we put forward, as a candidate for Néel-type skyrmion lattice, the isostructural , which is systematically studied via both first-principles calculations and Monte Carlo simulations of a model Hamiltonian. Electric polarization, driven by the Jahn-Teller distortion, is predicted to arise in , showing a comparable size but an opposite sign with respect to that evaluated in V-based counterparts and explained in terms of different electron counting arguments and resulting distortions. Interestingly, a larger spin-orbit coupling of orbitals with respect to orbitals in vanadium spinels leads to stronger Dzyaloshinskii-Moriya interactions, which are beneficial to stabilize a cycloidal spin texture, as well as smaller-sized skyrmions . Furthermore, the possibly large exchange anisotropy of may lead to a ferroelectric-ferromagnetic ground state as an alternative to the ferroelectric-skyrmionic one, thus calling for further experimental verification.
- Received 29 March 2019
DOI:https://doi.org/10.1103/PhysRevB.99.214427
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