STRUCTURAL, MAGNETO TRANSPORT AND MAGNETIC STUDIES OF Sr2.xPrx.FeMoO6

Abstract

Rare Earth doped Polycrystalline doubleperovskite compound Sr2PrFeMoO6 (x. 0.0, 0.05, 0.10, 0.15, 0.20, 0.25) were prepared by standard solid state reaction method in two step reaction process. Crystal structure, grain morphology, transport and magnetic properties of the samples were investigated by means of X-Ray powder diffraction, FESEM, Four probe R-T measurement and SQUID. The XRD pattern shows that all the samples are single phase and belong to the I4/m space group. and no additional impurity phase were observed on doping. The value of lattice constants a, c and volume of unit cell decreases due to the smaller ion Pr3+ doping for Sr2+ ion. FESEM analysis shows that the grain size decreases on increasing the doping concentration x. Resistance of all the samples decreases on increasing doping concentration and shows a semiconductor like behavior up to room temperature then increases gradually, and further a sharp decrease in resistance was investigated and this metal insulator type of transition was observed for all the samples. This transition for Pure SFMO was found at 409.2 K which is very close to the Tc of pure SFMO (410K) and increases with increasing x. The magnetoresistance measured at I Tesla show s+ a slight decrease with increasing temperature up to room temperature and it increases with further increase, in temperature and get a maximum value near TM!. The value of MR with doping concentration x increases up to x = 0.15 and then decrease with further increase in x. The magnetic measurement shows that all the samples are ferromagnetic at room temperature and Tc of the samples is above room temperature. The saturation magnetization for pure SFMO was found as 19.15 emu/gm which decrease up to 13.71 for x = 0.25.