Tunability of dielectric, optical and magnetic property by simultaneous co-substitution in LaFeO3

We report room temperature tunability of structural, dielectric, optical and magnetic properties by Ca/Mn co-substitution in LaFeO3. XRD reveals single phase formation. The co-substitution driven lattice strains are noticed in terms of changes in Fe/Mn-O-Fe/Mn bond angle and bond lengths. The XRD results on structural parameters are corroborated with Fourier transform infrared spectrum. The change in magnetic response appear to be well correlated with structural distortion in terms of Fe/Mn-O-Fe/Mn bond angle deviation and possible indirect exchange interactions between Fe and Mn via intervening oxide ion. Substantial improvement in dielectric response (εr ∼ 103) at RT was noted on co-substitution in LaFeO3. The dielectric spectrum exhibits non Debye type behavior and the same is confirmed in modulus spectrum. Modulus spectrum confirmed the presence of concentration dependent relaxation. Dielectric and optical property seems consistent with electrical conductivity changes as a function of concentration. Evidence of thermally activated Arrhenius type conduction is noticed.