The effect on physical properties of the substitution of Ca or Ba for Sr in NdSrNiO4

A new solid solution series, NdSr1 − xMxNiO4 (M = Ca: 0.0 ≤ x ≤ 1.0; M = Ba: 0.0 ≤ x ≤ 0.6), was synthesized by solid state reaction, and the structures, magnetic and electrical properties and optical spectra of this series have been studied. All the samples crystalized in tetragonal systems, with the exception of NdCaNiO4, which crystallized in the orthohombic system. IR spectra of NdSr1−xCaxNiO4 indicated that the lengths of two Ni-O bonds decrease with increasing Ca content. The electrical conduction changed from metallic-type to semiconductive-type when x ≥ 0.4 (M = Ca, Ba), and the room temperature resistivities of NdSr1 − xCaxNiO4 increased with the increase of Ca content. Magnetic susceptibility measurements revealed that Ni+3 ions in all the samplies were in low-spin state over the temperature range 77–300 K.