Effect of the size factor on the magnetic properties of manganite La0.50Ba0.50MnO3

摘要: Nanocrystalline manganite La0.50Ba0.50MnO3 was synthesized by an optimized sol-gel method. The initial sample subjected to step-by-step heat treatment under air atmosphere. ion stoichiometry, the morphology of crystallites ceramics, and magnetic properties were studied. It is established that average crystallite size D increases from ∼30 nm ∼7 μm with increasing annealing temperature. All samples studied are characterized a perovskite-like cubic structure, unit cell parameter continuously ∼3.787 ∼3.904 A size. most significant lattice compression (≈3%) occurs in nm. increase causes nonmonotonic Curic temperature T C ∼264 ∼331 K spontaneous moment σ S ∼1.52 ∼3.31 μB/f.u. anomalous behavior obtained explained competition between two effects, namely, frustration indirect exchange interactions Mn3+-O-Mn4+ on nanocrystallite surface crystal due tension.