ZnO–Fe3O4 composite prepared by sol-gel method with H2 deoxidation

Fe doped ZnO powder samples (Fe/Zn=0.05 and 0.1) were prepared by sol-gel method with H2 deoxidation at 450 ∘C for several hours or just heated in air at the same temperature. It was showed by vibrating sample magnetometer (VSM) that samples heat treated in H2 could show strong ferromagnetism at room temperature while samples treated in air only show very weak magnetism. XRD using Co k α X-ray revealed that the samples heated in H2 were not pure phase but like a granular system and the magnetism mainly results from Fe3O4 in samples while samples heated in air showed pure ZnO phase. Our work indicated that H2 deoxidation treatment may be an effective technique to fabricate such magnetic semiconductor-like materials with Curie temperature higher than room temperature.