Bulk аnd Nano Manganite Materials. White emitting colour

      Аннотация: The prepared nano pervoskite samples shows paramagnetic behaviour in the compounds prepared by SS method, but when it is prepared by SC method, it becomes superparamagnetic due to a partial migration of divalent ions to different sites. Due to substitution of lead / barium / strontion, intra-sublattice interaction become comparable with inter-sublattice interaction. In such a situation disorder and frustration takes place in the spin subsystem leading to the various magnetic structures; ferrimagnetic order, local spin canting, antiferrimagentic order, re-entrant spin glass (RSG) and spin glass etc. The magnetic ordering in these compounds is based on the Neel’s two sub-lattice model of magnetism. The addition of Ba / Sr / Pb ions forces the same number of other cations to the different magnetic sites as a result the magnetic moment of the previous site increases hence magnetization and magnetic moment increase due to pb2+ / Ba2+/ Sr2+. The curves shape shows superparamagnetic character of the investigated sample, with optimized saturation magnetization and almost zero coercivity values.

Ключевые слова: white emitting colour, Excitation spectra, Magnetic Materials, Photo-luminescence