Dysprosium Doping Induced Correlated Electrical And Optical Behaviour Of Magnetite Nanoparticles.

We report here the investigations on dependence of structural, electrical and optical properties of Fe3-xDyxO4 nanoparticles on the Dy doping levels. The nanoparticles were prepared by employing co-precipitation method and were characterized using TEM, XRD, UV-Vis spectroscopy and dc conductivity. TEM images showed round shaped particles along with rod like structures. The number of rods rises with increase in dysprosium doping. The value of resistivity has been observed to be 4.02 x 106 Ohm-cm for undoped samples. With dysprosium doping, the resistivity first decreases and then attains a peak value of 1.66 x 106 Ohm-cm at a critical doping level of x=0.03. UV-Vis spectroscopy has been used to calculate the band gaps with the help of Tauc plots. Band gap for undoped particle is 2.46 eV which first decreases and again attains a peak at x=0.03 having a band gap of 2.30 eV thereby corelated to the electrical behaviour. The magnetization curves reveal maximum saturation magnetization at the same doping concentration. [ABSTRACT FROM AUTHOR]