Magneto-Dielectric investigation in partially disordered Tb₂CoMnO₆ thin film

Relaxor ferroelectrics are recognized as a family of disordered or partially ordered materials that are classified as a special class of dipolar glass with the formation of weakly interacting polarized nano domains (PNR) bellow a certain temperature. They are distinguished from normal ferroelectric materials in terms of broad transition in the temperature dependent dielectric constant and the dispersion of the transition temperature with applied frequency. Here we report the observation of magneto-dielectrically coupled ferroelectric relaxation at quite high temperature (200K) in Tb₂CoMnO₆/STO(100) double perovskite thin film. Partially B site disordered film has been grown by means of a metal-organic aerosol deposition (MAD) technique. This material is reported as ferromagnetic insulator with T_C around 90K. Here we observe an enhanced transition temperature of 110K due to in plane strain. The deviation from the Curie-Weiss law far above T_C indicates the development of short range spin correlation which is getting coupled with the electric dipoles present in the system.