Structural, electrical, and magnetic properties of Ce doped La0.7Ca0.3MnO3 thin films

Abstract

We have studied the structural, transport, and magnetic properties of La0.7Ca0.3−xCexMnO3 (x = 0.0, 0.025, 0.05, 0.1, and 0.15) manganite thin films on LaAlO3 (100) substrate prepared by pulsed laser deposition technique. The grown films are single phase and epitaxial in nature as revealed by x-ray diffraction and in-plane phi-scan. The temperature dependent resistivity measurements of these films reveal a metal–semiconductor transition at TP and transition temperature is found to shift lower temperature with Ce doping. Resistivity data at high temperature have been fitted with the variable range hopping model to estimate the density of states at Fermi level {N (EF)}, while at low temperature electron–electron, electron–phonon, and electron-magnon processes contribute to scattering of carriers. It was observed that N(EF) decreases with Ce doping leads to a decrease in conductivity of the Ce doped samples. We have observed maximum magnetoresistance value ∼90% near the TP. Magnetization measurements reveal that long-range ferromagnetic ordering in all samples and that saturation magnetic moment increases as x increases.