Piezoelectric response and ferromagnetic order in 2D Janus FeGeN3

Abstract

Two-dimensional (2D) materials with ferromagnetism and piezoelectricity have drawn great attention due to their promising application and fundamental significance. Using first-principles swarm structure search calculations, we have predicted a 2D Janus FeGeN3, with quintet atomic layers of N–Fe–N–Ge–N, demonstrating a desirable coexistence of ferromagnetism and piezoelectricity. It has an out-of-plane piezoelectric response of −0.31 pm/V, a robust ferromagnetic order with a Curie temperature (TC) of 302 K, and an excellent semiconductivity with a bandgap of 1.99 eV. Its ferromagnetic coupling is derived from the super-exchange interaction between Fe atoms mediated by multi-type N atoms. Moreover, the biaxial tensile strain is in the favor of the enhancement of ferromagnetism. These intriguing properties make Janus FeGeN3 an attractive candidate for spintronic devices with multifunctionality.

Ferromagnetism above room temperature in Janus Fe2X (X = S, Se) monolayers

“…Iron (Fe), as a representative magnetic TM element, also exhibits promising potential for 2D high-temperature magnetic materials, 18–21 especially for Fe-based chalcogenides. 22 In detail, the prepared tetragonal/hexagonal FeTe monolayer demonstrates antiferromagnetism/ferromagnetism with a T C ranging from 170 to 220 K. 23,24 Hexagonal FeS 2 , FeSe 2 , and FeTe 2 monolayers are predicted to have intrinsic ferromagnetism with outstanding stability.…”