Effect of substitution of magnetic rare earth Nd at non-magnetic La site on structure and properties of LaSrFeO4

Abstract K 2 NiF 4 phases La 1− x Nd x SrFeO 4 ( x =0.0, 0.3, 0.6, and 0.9) have been successfully prepared by solid-state reactions. Rietveld refinement shows that all the phases crystallize in tetragonal K 2 NiF 4 structure (space group I4 / mmm ). The change in the lattice constants was interpreted in terms of the ionic radius of the substituted ion. The variation of inverse molar susceptibility with temperature follows the Curie–Weiss law. The dominant magnetic interactions in the materials are antiferromagnetic, which could be due to Fe 3+ –O–Fe 3+ superexchange coupling. All the samples were semiconducting over the temperature range from 150 to 350 K and the resistivity data has been best fitted using the Arrhenius equation, ρ = ρ 0 exp(– E a / k B T ).