EFFECT OF PARTICLE SIZE ON THE STRUCTURAL AND TRANSPORT PROPERTIES of La0.67Ca0.33MnO3 NANOPARTICLES

ABSTRACT: The effect of nanometric particle size on structural and transport properties of single phase, nanocrystalline, granular La0.67Ca0.33MnO3 (LCMO) is investigated. The materials were synthesized using the modified citrate route by sintering at five different temperatures starting from 600 to 1000 °C, with an interval of 100 °C. XRD analysis showed that the particle size increases with the increase in sintering temperature. A systematic study of electrical resistivity of all five samples was undertaken as a function of temperature (80–300 K). The metal-insulator transition temperature (TP) was determined, which increases (from 114 to 193 K) with increase in sintering temperature. Most interestingly, transport measurements show that with the increase in annealing temperature, the effect gets more pronounced with the increase in particle size. These transport measurements were counterchecked by magnetic (AC susceptibility) and thermal (Differential Scanning Calorimeter (DSC)) measurements and found in good agreement with each other. The core-shell model has been applied to the data for theoretical explanation