Two-dimensional room temperature ferromagnetic semiconductors

TL;DR

This paper uses density functional theory to propose a method for transforming 2D ferromagnetic metals into high Curie temperature ferromagnetic semiconductors through element replacement, predicting several candidates with TC above 200 K.

Contribution

It introduces a novel element replacement strategy to design 2D high TC ferromagnetic semiconductors from existing ferromagnetic metals.

Findings

Predicted 10 ferromagnetic semiconductors with TC above 200 K.

Identified several candidates with TC above 300 K.

Proposed a feasible approach for experimental realization.

Abstract

To realize ferromagnetic semiconductors with high Curie temperature TC is still a challenge in spintronics. Recent experiments have obtained two-dimensional (2D) room temperature ferromagnetic metals, such as monolayers MnSe2 and Cr3Te6. In this paper, by the density functional theory (DFT) calculations, we proposed a way to obtain 2D high TC ferromagnetic semiconductors through element replacement in these ferromagnetic metals. High TC ferromagnetic semiconductors are predicted in the monolayers (Mn, D)Se2 and (Cr, D)3Te6, where element D is taken as vacancy, 3d, 4d and 5d transition metal elements. For the concentrations of D from 1/9 to 1/3, there are about 10 ferromagnetic semiconductors with TC above 200 K, including (Cr5/6, W1/6)3Te6 and (Cr4/6, Mo2/6)3Te6 with TC above 300 K. In addition, Mn(Se6/8, Sb2/8)2 is also predicted to be a 2D ferromagnetic semiconductor with TC above 300 K. Considering the fast developments on fabrication and manipulation of 2D materials, our theoretical results propose a way to explore the high temperature ferromagnetic semiconductors from experimentally obtained 2D high temperature ferromagnetic metals through element replacement approach.