Magnetic and transport properties of Mo substituted La0.67Ba0.33Mn1-xMoxO3 perovskite system

Abstract

The effect of doping Mo for Mn on the magnetic and transport properties of the colossal magnetoresistance material, La0.67Ba0.33MnO3, has been studied. Compounds of the series La0.67Ba0.33Mn1-xMoxO3 (x=0.0 to 0.1) have been prepared and found to crystallize in the orthorhombic structure (space group Pbnm). Energy Dispersive X-ray Analysis (EDAX) measurements confirm the stoichiometry of all the samples. Magnetotransport and magnetization measurements reveal that the metal-insulator transition temperature (Tp) decreases from 330K for x=0 to 255K for x=0.1. The change in Tp on Mo substitution is relatively much smaller than the corresponding change observed on substitution by other transition elements, such as Ti, Fe, Co, Ni, etc. Further, the ferromagnetic transition temperature (TC) is nearly unchanged by Mo substitution. This is in striking contrast to the large decrease in TC observed with substitution of above-mentioned 3d elements. These unusual magnetic and transport properties of La0.67Ba0.33Mn1-xMoxO3 may be either due to the formation of magnetic pair between Mn and Mo or due to strong Mo(4d)-O(2p) overlap, which in turn, may affect the Mn-Mn interaction via the oxygen atoms