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arXiv · 1905.03545

Two-dimensional ferromagnetic-ferroelectric multiferroics in violation of the d0 rule

Hengxin Tan·Menglei Li·Haitao Liu·Zhirong Liu·Yuanchang Li·Wenhui Duan
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Abstract

Contribution of d-electron to ferroelectricity of type-II multiferroics causes strong magneto-electric coupling and distinguishes them from the conventional type-I multiferroics. However, their therein polarization is too small because the ferroelectricity is merely a derivative from the magnetic order. Here we report a new class of multiferroic materials, monolayer VOX2 (X = Cl, Br, and I), which combine the advantages of type-I and type-II multiferroics. Both ferroelectricity and magnetism arise from the same V cation, where the filled d-orbital is perpendicular to an a priori ferroelectric polarization and thus poses no hindrance to ferroelectricity, indicating a violation of the usual d0 rule. This makes the combination of large polarizations and strong magneto-electric coupling possible. Our findings not only add new ferromagnetic-ferroelectric multiferroics, but also point to a unique mechanism to engineer multiferroics.

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Hengxin Tan, Menglei Li, Haitao Liu, Zhirong Liu, Yuanchang Li, Wenhui Duan. 2019-05-09. Two-dimensional ferromagnetic-ferroelectric multiferroics in violation of the d0 rule. https://doi.org/10.1103/physrevb.99.195434

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