Evolution of Temperature-Dependent Electrical and Magnetic Behavior in a Series of Antimonate Triple Perovskite Sr ₃ CoSb 2– x Ti x O ₉

Motivated by several claims of perovskites that incorporate Sr metal at the A site, they frequently exhibit distinctive orthorhombic structures, which feature multiple potential sites that the B cations are able to acquire. It has been well-established that Sr₃Sb2-xTixCoO₉ (x = 0.0, 0.1, and 0.5) exhibits a single-phase orthorhombic structure (Immm space group). This outlines a chance to explore the onset of electronic and magnetic characteristics in accordance with the doping levels. Temperature-dependent magnetic susceptibility measurements exhibit the divergence between ZFC and FC curves at low temperatures, indicating magnetic irreversibility and the onset of spin frustration. Curie-Weiss analysis indicates elevated effective magnetic moments and progressively negative Weiss temperatures with doping, aligning with developed antiferromagnetic interactions and the onset of magnetic frustration. The M-H and Arrott plots validate the presence of mild ferromagnetic characteristics in doped samples, presumably resulting from Co²⁺/Co³⁺ valence variations caused by Ti⁴⁺ substitution. Dielectric measurements reveal significant frequency dispersion and relaxor-type behavior, with ac conductivity conforming to the associated CBH and NSPT models for the respective doping series. The fluctuation of s parameters with temperature further corroborates the influence of thermally activated charge dynamics. These findings emphasize the dual function of Ti⁴⁺ doping in influencing spin correlations and dielectric relaxation, indicating potential multifunctional applications in magneto-dielectric materials.