Morphology and Functional Properties of Magnetic Nanoparticles of Lanthanum-Strontium Manganites

Structure, morphology, magnetic state and magnetocaloric effect of single-phase nanopowder La
_0.6
Sr
_0.4
MnO
₃
manganites have been investigated by X-ray diffraction, BET, SEM, and magnetic methods. According to X-ray diffraction, BET and SEM data, an average size of particles for the La
_0.6
Sr
_0.4
MnO
₃
composition is tens of nanometers. On the basis of analysis of the magnetic data, the magnetic states, phase transition temperatures, magnetocaloric effect as well as critical sizes of particles, i.e. boundary sizes of a single-domain state, a vortex state and a multi-domain state, have been determined. The most part of nanoparticles of the La
_0.6
Sr
_0.4
MnO
₃
composition are in the single-domain state.