Dielectric absorption correlated to ferromagnetic behavior in (Cr, Ni)-codoped 4H–SiC for microwave applications

Abstract

For (Cr, Ni)-codoped 4H silicon carbide SiC, electronic/optical properties are calculated, and a ferromagnetic (FM) order is detected. Doping Ni at Si sites should not destroy the effective coupling of the spins induced by Cr, could enormously boost the quality of absorbing electromagnetic waves, and acts as resist coatings for Cr-doped 4H-SiC. The metallic character shown by (Ni, Cr)-codoped 4H–SiC allow us using it in microwave circuits. Its FM order is mainly due to Cr impurities, so that the strong FM coupling originates from p-d hybridization interaction. Our results show that substituting Al for Ni either in (Al, Cr) or (Al, Cr)-doped 4H-SiC may improve the magnetism of 4H–SiCand enhance its microwave absorbing properties in the mm-wave band.