Fe doping and magnetic properties of zincblende SiC ceramics

Fe-doped SiC bulk ceramics were fabricated by hot-pressing, and their magnetic and electronic properties were investigated. Si1-xFexC (x <= 0.04) samples having a zincblende crystal structure exhibited ferromagnetic hysteresis at room temperature with the saturation magnetization increasing with x. X-ray diffraction measurements revealed the creation of a Fe3Si phase in the samples with its density increasing with x. The samples were found to be p-type semiconductors with a hole concentration (electrical resistivity) of similar to 10(19) cm(-3) (similar to 10(0) Omega cm) at room temperature. The observed magnetic properties of the samples are mainly ascribed to the presence of ferromagnetic Fe3Si crystallites. The high carrier concentration of the samples likely implies the existence of acceptors due to individual Fe3+ occupation of the Si sites in the lattice. The randomly distributed Fe3+ ions represent a minor contribution to the magnetization of the samples through the formation of magnetic polarons with the carriers. (C) 2011 Elsevier Ltd. All rights reserved.