Intrinsic room-temperature ferromagnetic semiconductor InCrTe3 monolayers with large magnetic anisotropy and large piezoelectricity

Abstract

A tremendous amount of research is currently focused on two-dimensional (2D) magnetic semiconductors because of their remarkable physical properties and diverse applications. However, their applications are highly limited by the low Curie temperature (TC). Based on first-principles calculations and Monte Carlo simulations, we demonstrate that 2D InCrTe3 monolayers are ideal candidates for next-generation spintronics applications. We show that 2D InCrTe3 monolayers have thermodynamical and mechanical stability. The magnetic couplings between Cr atoms are strong ferromagnetic (FM) interactions. 2D InCrTe3 monolayers have robust FM semiconducting behavior with a bandgap of ∼0.67 eV, adequate TC (higher than ∼300 K), and a giant out-of-plane magnetic anisotropy energy (MAE) of ∼1.4 meV/Cr. Moreover, the low symmetry C3v point group leads to large in-plane piezoelectric coefficients d11 (larger than 4.8 pm/V) and out-of-plane piezoelectric coefficients d31 (larger than 0.39 pm/V), which are higher than many Janus transition metal dichalcogenides. The theoretical predictions of high TC, large MAE, and piezoelectricity in 2D InCrTe3 monolayers suggest that they have great potential for applications in spintronics, nano-sized sensors, and electromechanics.

Predicted ferromagnetic monolayer CrSCl with large vertical piezoelectric response: A first-principles study

“…For example NiClI monolayer, the large out-of-plane piezoelectricity (d 31 =1.89 pm/V) has been predicted, but it has very weak FM coupling and in-plane magnetic anisotropy [10]. For InCrTe 3 monolayer, it has large FM coupling and out-of-plane magnetic anisotropy, but the out-of-plane piezoelectricity is weak (d 31 =0.39 pm/V) [9]. Therefore, searching for 2D PFMs with strong out-of-plane FM coupling and large vertical piezoelectric response is significative and challenging.…”

“…The piezoelectric properties of ferrovalley (FV) materials have been investigated [3,4], and the anomalous valley Hall effect induced by piezoelectric effect has been proposed in GdCl 2 monolayer [4]. Searching for PFMs has been a research hotspot [5][6][7][8][9][10]. An eminent 2D PFM with a typical triangle lattice structure should meet these conditions: (1) the strong FM coupling, which means high Curie temperature; (2) the outof-plane magnetic anisotropy, which means a long-range phase, not a quasi-long-range phase; (3) the large outof-plane piezoresponse, which is highly desirable for ultrathin piezoelectric device application.…”

Huge out-of-plane piezoelectric response in ferromagnetic monolayer NiClI

“…The PFMs have been predicted in 2D vanadium dichalcogenides, VSi 2 P 4 , CrBr 1.5 I 1. 5 and InCrTe 3 [17][18][19][20] . The piezoelectric quantum anomalous Hall insulator (PQAHI), which combines piezoelectricity with topological and FM orders, has been reported in Janus monolayer Fe 2 IX (X=Cl and Br) 21 .…”

Coexistence of intrinsic piezoelectricity and nontrivial band topology in monolayer InXO (X = Se and Te)

“…In the 2D vanadium dichalcogenides, VSi 2 P 4 , CrBr 1.5 I 1. 5 and InCrTe 3 [25][26][27][28] , the piezoelectric ferromagnetism (PFM) has been predicted, which combines piezoelectricity and ferromagnetism. The combination of piezoelectricity with topological insulating phase, namely piezoelectric quantum spin Hall insulator (PQSHI), has also been realized in monolayer InXO (X=Se and Te) 29 and Janus monolayer SrAlGaSe 4 30 .…”