Impact of the sintering temperature  on the structural and magnetoresistive  properties of Nanophasic  La0.70Ca0.25K0.05MnO3 manganite

S. R. Mankadia; J. A. Bhalodia

Volume : II, Issue : V, May - 2013

Impact of the sintering temperature on the structural and magnetoresistive properties of Nanophasic La0.70Ca0.25K0.05MnO3 manganite

S. R. Mankadia, J. A. Bhalodia

Abstract :

A systematic investigation of the La0.70Ca0.25K0.05MnO3 perovskite had been undertaken, mainly to understand the influence of the sintering temperature on the structural and magnetoresistance properties in this material. The La0.70Ca0.25K0.05MnO3 manganite was prepared by a modified auto–combustion method at 600 �C and 1000 �C. The X–ray diffraction studies show that both the samples are crystallized with the orthorhombic symmetry within the space group Pnma. The effect of sintering temperature was observed on lattice parameters, full width half maxima and crystallite size. The crystallite sizes and strain of the samples were determined using Hall–Williamson method. With increasing sintering temperature, the crystallite size increases, whereas the strain value decreases. Isotherm magnetoresistance (MR) measurements were carried out at various temperatures (5 K, 150 K, 200 K, 250 K and 300 K) between 0 to 8 T and strong impact of sintering temperature on MR was observed. The extrinsic MR effect might be responsible for such behavior.