Magnetic properties of diluted magnetic semiconductor nanowires CoxSn1−xO2

Abstract

SnO 2 and CoxSn1−xO2 (x=0.013–0.22) nanowires were fabricated using a catalyzer assisted chemical vapor deposition. The as-grown nanowires are homogeneous along the wire length with diameters ranging from 33 to 250 nm and lengths greater than 15 μm. The morphology of the nanowires is sensitive to the fabrication conditions such as selection of catalyzer, flux rates of O2 and Ar, as well as deposition temperature. The growth mechanism of nanowires can be ascribed to a vapor-liquid-solid [R. S. Wagner and W. C. Ellis, Appl. Phys. Lett. 4, 89 (1964)] process. All CoxSn1−xO2 nanowires exhibit room temperature ferromagnetism. Magnetic moment per Co ion reaches 1.8 μB for the sample of x=0.016 and sharply decreases as x is increased. Nanowires are single crystals and no Co clusters or oxides are found for all samples, implying that the observed ferromagnetism is intrinsic.