Investigations on the structural, electrical and magnetic properties of Nd_2-xM_xNiO_4+δ, M = Ca²⁺ and Ba²⁺

It is shown that the Nd_2-xBa_xNiO_4+δ with x greater than 0.5 show large amounts of an impurity phase(s) in the XRD pattern which have not been properly characterized so far. For this reason only samples with x equal to or less than 0.5 are reported in this study. As discussed, the extent of the splitting in the hkO reflections of the orthorhombic speciments served as an indicator of the degree of distortion from the tetragona; symmetry. Even though the low angle reflections did not show any divergence in the hkO refelctions, the high angle data showed peak brosdening in the coresponding refelctions indicating that the actual symmetry could be lower than tetragonal.