Synthesis and characterization of layered perovskite oxides (La, Sr)n + 1(Ti, Cr)nO3n + 1 (n = 1, 2)

We report here the synthesis of layered perovskite oxides of the composition La0.5Sr1.5Ti0.5Cr0.5O4 and LaSr2TiCrO7 by conventional solid-state reaction method. Results of XRD analysis show that the phases crystallize with tetragonal unit cell in the space group I4/mmm. Both phases behave as insulators and the linearity of log ρ versus T−1/4 plot in the temperature range 150–350 K suggests that the electronic conduction occurs by Mott’s variable range hopping mechanism. The antiferromagnetic interactions observed for the samples arise from Cr3+–O–Cr3+ superexchange interaction.