Fabrication and magnetic properties of electrospun zinc ferrite (ZnFe₂O₄) nanofibres

<jats:p> The present paper describes the fabrication of zinc ferrite (ZnFe<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub>) nanofibres by electrospinning method using a solution that contained polyvinyl pyrrolidone (PVP) and Zn and Fe nitrates as alternative metal sources. The as spun and calcined ZnFe<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub>/PVP composite samples were characterised by thermogravimetric differential thermal analysis, X-ray diffraction, Fourier transform infrared and SEM respectively. After calcination of the as spun ZnFe<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub>/PVP composite nanofibres (fibre size of 344 ± 76 nm in diameter) at 500, 600 and 700°C in air for 2 h, the nature of nanofibres was changed due to the reorganisation of the ZnFe<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub> structure at high temperature, and ZnFe<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub> nanofibres of 58–75 nm in diameter having well developed spinel structure were successfully obtained. The crystal structure and morphology of the nanofibres were influenced by the calcination temperature. The calcined ZnFe<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub> samples have a structure of packed particles or crystallites with crystallite sizes of 19, 20 and 26 nm for the samples calcined at 500, 600 and 700°C respectively. Room temperature magnetisation results showed a superparamagnetic behaviour of the ZnFe<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub> samples calcined at 500 and 600°C and a paramagnetic behaviour of the ZnFe<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub> samples calcined at 700°C. The specific magnetisation M<jats:sub>s</jats:sub> values at 10 kOe are 2·34, 2·55 and 1·53 emu g<jats:sup>–1</jats:sup> for the samples of ZnFe<jats:sub>2</jats:sub>O<jats:sub>4</jats:sub>/PVP composite nanofibres calcined at 500, 600 and 700°C respectively. </jats:p>