Magnetic Properties of Al ‐doped B ₄ C and SiC Ceramics

Abstract

Al ‐doped B 4 C and Al ‐doped SiC ceramic compounds were synthesized by high‐temperature solid‐state sintering. Ferromagnetic ( FM ) ordering was observed in the doped semiconducting ceramics. The changes in the FM ordering with doping level were different in the two doped systems although they were prepared by similar experimental condition. Our results indicated that some of the C in B 4 C were replaced by the Al atoms, and these displaced C atoms existed in the form of graphite. The synthesized SiC samples, undoped or Al doped, were found to be a mixture consisting of the magnetic and nonmagnetic SiC polytypes. The mechanisms in the generation of the FM ordering due to the dopants in the two ceramics followed different routes.