Synthesis, magnetic and transport properties of La0.7Ca0.15Sr0.15MnO3 nanoparticles.

Abstract

The nanocrystalline La_0.7Ca_0.15Sr_0.15MnO₃ compound have been synthesized by combustion method. X-ray diffraction of prepared samples crystallize in the rhombohedral (Rc) structure. The crystallite size increases with increasing annealing temperature. The magnetization data reveals the distinct suppression T_C i. e. the ferromagnetic (FM) to paramagnetic (PM) transition with decreasing crystallite size.  The transport properties show that the metal-insulator (T_MI) transition decreased and resistivity increases with decreasing crystallite size. The observed results are explained terms of the surface disorder and opening of strong AFM coupling at the expense of FM ordering in the nano crystallites of La_0.7Ca_0.15Sr_0.15MnO₃ system.