Study on magnetic properties of Fe-doped 3C-SiC nanowires

Abstract

With the development of semiconductor spintronics, dilute magnetic semiconductors have become a research hotspot recently. Fe-doped 3C-SiC nanowires (C/Si = 1.4) with ferromagnetism at 300 K were fabricated by LPCVD. The electronic structures and magnetic properties of Fe-doped 3C-SiC nanowires without or with vacancies were studied by first-principle calculation. The experimental results reveal that the samples mainly grew along the [1 1 1] direction and possessed the obvious ferromagnetism at 100 K, 200 K, and 300 K. The theoretical calculations show that Fe-doped nanowires without vacancy are metallic property and non-magnetic, Fe-doped nanowires with C vacancy are metallic property and stable antiferromagnetism, and Fe-doped nanowires with Si vacancy are half-metal materials and stable ferromagnetism. The results of the density of states indicate that the magnetism originates from the hybridization of Fe-3d, C-2p and Si-3p states. The room temperature ferromagnetism of the 3C-SiC nanowires should be attributed to the coexistence of Fe impurity and Si vacancy.