Emergence of Magnetoelectric-relaxor Phase in La3Ni2TaO9

Abstract We report a rare magnetoelectric relaxor phenomenon in double perovskite La3Ni2TaO9. To unveil this exotic property, we have systematically examined its physical characteristics via magnetic and electric susceptibilities. DC magnetization shows magnetic anomaly at 25 K (Tg) and becomes irreversible under ZFC and FC protocol. The thermal profile of dielectric constant (e) and loss (tanδ) exhibit anomaly in the vicinity of magnetic ordering temperatures and the peaks shift towards higher temperatures at higher frequencies. This co-occurrence indicates a strong correlation between magnetic and dielectric properties. To further corroborate, we measured dielectric constant e(T), in presence of external magnetic fields. It is observed that upon application of magnetic field e(T) increases and tanδ(T) shows upturn, near Tg, which confirms magneto-electric nature of La3Ni2TaO9. Additionally, it is observed that the DC susceptibility exhibits an upturn up to Tg along with broad anomaly. Inverse of AC susceptibility is fitted with modified Curie–Weiss law which shows non-linear characteristics. Dielectric and magnetic properties collectively establish that La3Ni2TaO9 belongs to the magnetoelectric relaxor family.