Compound from the solid-solution NdSrNi1−xCrxO4−δ, 0≤x≤1, has been prepared using conventional solid-state method and was characterized by X-ray powder diffraction. The NdSrNi0.5Cr0.5O4−δ sample shows the adoption of the K2NiF4-type structure based on the tolerance factor calculation. X-ray diffraction analysis using the Rietveld method was carried out and it was found that NdSrNi0.5Cr0.5O4−δ compound crystallizes in tetragonal symmetry with space group I4/mmm. The lattice parameters are found to be at room temperature, a=3.8012(3) Å and c=12.4812(1) Å. For X-ray diffraction data, the reliability factors are RB=0.034, Rwp=0.089, , and χ2=1.17. Bond-valence sum calculations were performed for nickel and chromium. The changes in unit-cell parameters are discussed in terms of oxygen stoichiometry and transition metal (3d) oxidation state from the perspective of the Brown bond-valence sum calculation theory.
