Structural and magnetic properties of chemically disordered perovskite SrTi0.5Mn0.5O3

Single phase polycrystalline sample of perovskite SrTi0.5Mn0.5O3 (STMO) has been successfully synthesized via solid state reaction route. Its detailed structural and physical properties have been studied using powder x-ray diffraction (XRD), transmission electron microscopy (TEM), magnetization, specific heat, and dielectric measurements. Rietveld analysis of the powder XRD data and TEM studies confirm that STMO is a disordered perovskite with Pm-3m space group in which titanium and manganese ions are randomly distributed at the 1b site. The dc magnetization (χdc-vs-T) measurements in the temperature range 2-300 K reveal a single anomaly at ∼13 K with predominant long range canted antiferromagnetic (AFM) ordering. The frequency invariant maximum at 13 K in the ac susceptibility (χac-vs-T) data discards the spin-glass behavior. Despite the presence of sharp feature in magnetization data, the specific heat data (Cp-vs-T) shows only a broad hump around 13 K, which has been attributed to the magneto-structural ordering giving rise to canted AFM state in chemically disorder STMO. Matching with the magnetic and specific heat anomaly, the dielectric permittivity also shows a broad anomaly around 13 K, indicating the possible magneto-dielectric coupling in STMO system.