Preparation of Fe doped ZnO thin films and their structural, magnetic, electrical characterization

Abstract

Fe doped ZnO thin films having chemical composition of Zn(1-x)FexO (x = 0.0, 0.05, 0.10, 0.15, 0.20) from one molar concentration of precursor sol was synthesized over glass substrate by sol-gel spin coating method. The XRD analysis of the samples reveals the wurtzite ZnO crystallite size reduces from 18.2 nm to 11.4 nm with the increase in Fe content from x = 0 to 0.20. The cubic spinel ZnFe2O4 is identified in the XRD pattern of high (x = 0.20) Fe containing sample. FESEM micrographs reveal that the average particle size reduces from 49.41 to 27.72 nm with the increase in Fe content from x = 0 to 0.20. Whereas, SPM images show that increasing Fe content reduces surface roughness of the films. TEM analysis of Fe (x = 0.10) doped ZnO system supports the phase identification by XRD and particle size analysis by FESEM. The VSM analysis reveals magnetization (Mr) of the samples from the M-H curve. SQUID analysis reveals magnetic properties indicating the formation of room temperature ferromagnetic material (RTFM). The value of saturation magnetization increases from 0.01 to 1.1 emu/gm with the increase in Fe content from 0 to 0.20. Electrical conductivity measurement of the thin film sample using four probe technique indicates that films are semiconducting in nature with electrical resistance (R) of the films varying from 99.8 to 163.3 Ω with the increase in Fe doping concentration from 0 to 0.10.