Investigation of optical, electrical and magnetic properties of Tb-doped ZnO nanorods

The hydrothermally synthesised nanorods of Zn_1 − xTb_xO(x = 0.00, 0.02, 0.05, 0.1) were carried over here to analyse the changes in its optical, magnetic and electrical behavior on doping. Formation of hexagonal wurtzite structure with particle size in the range of 36 nm–22 nm was confirmed by X-Ray diffraction studies. The morphology of the samples was confirmed by SEM (Scanning electron microscope) images alongwith its TEM (transmission electron microscope) micrographs. SAED (Selected area electron diffraction) and HRTEM (High resolution transmission electron microscope) shows the clear formation of nanorods. The quantitative analysis of elemental composition was done by energy dispersive X-ray spectroscopy (EDAX). The effect of increase in dopant concentration on band gap was analysed by UV-vis spectra; the band gap was found to be 3.35, 3.31, 3.30, 3.28 eV for undoped and 2%, 5% and 10% Tb-doped ZnO nanorods respectively. The presence of various types of defects was verified by PL study. The room temperature ferromagnetism behavior was tested by VSM and saturation magentization varies from 0.004 emu/g to 0.05 emu/g for undoped to 10% tb-doped ZnO nanorods. The dependence of resistivity on dopant concentration was carried out by four probe method which shows rise in resistivity with increasing dopant concentration.