Microstructure and magnetoresistance in La0.67Ca0.33Mn1−xVxO3 (x = 0, 0.03, 0.06, 0.1, 0.15 and 0.25) compound

The microstructure and magnetoresistance properties of the polycrystalline La0.67Ca0.3Mn1−xVxO3 were systematically investigated as a function of V-doping level. X-ray powder diffraction indicated that the substitution of Mn by V produced no structural change and only the diffraction lines for cubic perovskite were obtained for all samples. The detailed EDX analysis showed the existence of two phases in La0.67Ca0.3Mn1−xVxO3 (x = 0.03, 0.06, 0.1, 0.15 and 0.25) samples. The temperature dependence of resistance showed two maxima in the V-doped sample for x ≤ 0.15, and the peak value of magnetoresistance (MR) around insulator–metal transition temperature was increased with V-doping. Double maxima in the resistance–temperature curves were explained by the existence of two phases in La0.67Ca0.3Mn1−xVxO3 samples.