npj Computational Materials (Apr 2022)

Ferroelectricity coexisted with p-orbital ferromagnetism and metallicity in two-dimensional metal oxynitrides

  • Haoqiang Ai,
  • Feifei Li,
  • Haoyun Bai,
  • Dong Liu,
  • Kin Ho Lo,
  • Shengyuan A. Yang,
  • Yoshiyuki Kawazoe,
  • Hui Pan

DOI
https://doi.org/10.1038/s41524-022-00737-3
Journal volume & issue
Vol. 8, no. 1
pp. 1 – 7

Abstract

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Abstract Two-dimensional (2D) multiferroics have attracted increasing interests in basic science and technological fields in recent years. However, most reported 2D magnetic ferroelectrics are based on the d-electron magnetism, which makes them rather rare due to the empirical d 0 rule and limits their applications for low magnetic phase transition temperature. In this work, we demonstrate that the ferroelectricity can coexist with the p-electron-induced ferromagnetism without the limitation of d 0 rule and metallicity in a family of stable 2D MXene-analogous oxynitrides, X 2NO2 (X = In, Tl). Remarkably, the itinerant character of p electrons can lead to the strong ferromagnetic metallic states. Furthermore, a possible magnetoelectric effect is manifested in a Tl2NO2/WTe2 heterostructure through the interface engineering. Our findings provide an alternative possible route toward 2D multiferroics and enrich the concept of ferroelectric metals.