Effect of Particle Size on Magnetic Phase Coexistence in Nanocrystalline La0.4Bi0.3Sr0.3MnO3

Abstract

AbstractMagnetic phase coexistence in the substituted perovskite compound, La0.4Bi0.3Sr0.3MnO3, is attributed to the spontaneous moment and a step-like metamagnetic transition observed in the magnetization measurements in its magnetically order state. The magnetism of samples reduced to nanometer sizes by the “top down” approach exhibits interesting changes with respect to the bulk, thus giving a handle in influencing the physical properties by reducing the particle size. The bulk sample orders ferromagnetically at TC = 295 K, whereas in nano-sized samples with particle sizes in the range of 21–30 nm, even though TC does not change, the transitions are suppressed. The nano-sized powder samples show a broad hump in the plot of magnetic susceptibility, signifying the possible disordered antiferromagnetic state. A systematic decrease in the magnitude of magnetization in nano-sized samples shows that the reduction in magnetic interaction could be attributed to the formation of a magnetic dead layer around the magnetic core.