Effect of the Jahn-Teller distortion on double exchange interaction in La0.8K0.2MnO3 nanoparticles

Abstract

Electric resistance and effect of hydrostatic pressure on magnetic properties has been studied on the La0.8K0.2MnO3 nanoparticles. Magnetic phase transition is affected by pressure only slightly, the Curie temperature TC decreases with the rate of -1.02 K/GPa, on samples with orthorhombic structure where the Jahn-Teller distortion of lattice is large. On the other hand, TC increases with the rate of 20.1 K/GPa on samples with rhombohedral structure, where the Jahn-Teller distortion of lattice is absent. Insulator type of electrical resistance is characteristic feature of sample with large Jahn-Teller distortion of lattice and insulator-metal transition was observed on samples where the Jahn-Teller distortion is negligible. Our results are in line with theoretical calculation predicting that double exchange interaction is suppressed by the Jahn-Teller distortion.