Structure and properties of electron-doped Ca1−xSmxMnO3 nanoparticles

In this paper, we report the structural and magnetic properties of electron-doped Ca1−xSmxMnO3 (CSM) nanoparticles. The samarium's composition “x” was varied from 0 to 0.2 with the special attention up to 0.05. Spherical 60–70 nm polycrystalline CSM nanoparticles were synthesised by chemical co-precipitation technique. Doping of Sm3+ in antiferromagnetic CaMnO3 has drastically altered its magnetic behavior due to the formation of ferromagnetic clusters. For example, the CSM powder with x = 0.04 displays about 115 K magnetic Curie temperature and about 0.1 emu/mole saturation magnetization. Physical properties of our nano-CSM powders are also compared with identical bulk-samples. To understand the differences, we invoked the intra-grain and inter-grain magnetic coupling process that facilitates to enhance their ferromagnetic behaviors. Unlike the bulk samples, such magnetic couplings in nanoparticles are favored by the presence of low-level crystal and interfacial defects.