Magnetic and gas sensing property of nanosized NiFe2O4 powders synthesized by pulsed wire discharge

摘要

Nickel ferrite (NiFe2O4) powders were synthesized by pulsed wire discharge method. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses show that only nickel ferrite spinel and no other phase was observed in the powders. Mean size of the obtained particles strongly depended on the oxygen pressure: the higher oxygen pressure corresponds to larger powder size, as determined by Brunauer-Emmet-Teller (BET). The room temperature saturation magnetization of the synthesized powders was 42-46 emu/g depending on the powder size. These powders also showed high chlorine sensitivity at about 280-360 degrees C, and a good linear sensitivity with chlorine concentration.