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 Sr 3 Sb 2– x Ti x CoO 9 ( 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 Co 2+ /Co 3+ valence variations caused by Ti 4+ 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 Ti 4+ doping in influencing spin correlations and dielectric relaxation, indicating potential multifunctional applications in magneto-dielectric materials.