THE EFFECT ON PHYSICAL-PROPERTIES OF THE SUBSTITUTION OF CA OR BA FORSR IN NDSRNIO4

A new solid solution series, NdSr(1-x)M(x)NiO(4) (M = Ca: 0.0 less tha n or equal to x less than or equal to 1.0; M = Ba: 0.0 less than or eq ual to x less than or equal to 0.6), was synthesized by solid state re action, and the structures, magnetic and electrical properties and opt ical spectra of this series have been studied. All the samples crystal ized in tetragonal systems, with the exception of NdCaNiO4, which crys tallized in the orthohombic system. IR spectra of NdSr1-xCaxNiO4 indic ated that the lengths of two Ni-O bonds decrease with increasing Ca co ntent. The electrical conduction changed from metallic-type to semicon ductive-type when x greater than or equal to 0.4 (M = Ca, Ba), and the room temperature resistivities of NdSr1-xCaxNiO4 increased with the i ncrease of Ca content. Magnetic susceptibility measurements revealed t hat Ni+3 ions in all the samplies were in low-spin state over the temp erature range 77-300 K.