Regulating the dopant clustering in LiZnAs-based diluted magnetic semiconductor

Abstract

Tuning of the magnetic interaction plays the vital role in reducing the clustering of magnetic dopant in diluted magnetic semiconductors (DMS). Due to the not well understood magnetic mechanism and the interplay between different magnetic mechanism, no efficient and universal tuning strategy is proposed at present. Here, the magnetic interactions and formation energies of isovalent doped (Mn) and aliovalent (Cr) doped LiZnAs are studied based on density functional theory (DFT). It is found that the dopant-dopant distance dependent magnetic interaction is highly sensitive to the carrier concentration and carrier type and can only be explained by the interplay between two magnetic mechanism, i.e. super-exchange and Zener’s p-d exchange model. Thus, the magnetic behavior and clustering of magnetic dopant can be tuned by the interplay between two magnetic mechanisms. The insensitivity of the tuning effect to U parameters suggests that our strategy could be universal to other DMS.