Emergent multiferroism with magnetodielectric coupling in EuTiO3 created by a negative pressure control of strong spin-phonon coupling
Run Zhao, Chao Yang, Hongguang Wang, Kai Jiang, Hua Wu, Shipeng Shen, Le Wang, Young Sun, Kuijuan Jin, Ju Gao, Li Chen, Haiyan Wang, Judith L. MacManus‐Driscoll, Peter A. van Aken, Jiawang Hong, Weiwei Li, Hao Yang
Abstract
Abstract Negative pressure has emerged as a powerful tool to tailor the physical properties of functional materials. However, a negative pressure control of spin-phonon coupling for engineering magnetism and multiferroicity has not been explored to date. Here, using uniform three-dimensional strain-induced negative pressure in nanocomposite films of (EuTiO 3 ) 0.5 :(MgO) 0.5 , we demonstrate an emergent multiferroicity with magnetodielectric coupling in EuTiO 3 , matching exactly with density functional theory calculations. Density functional theory calculations are further used to explore the underlying physics of antiferromagnetic-paraelectric to ferromagnetic-ferroelectric phase transitions, the spin-phonon coupling, and its correlation with negative pressures. The observation of magnetodielectric coupling in the EuTiO 3 reveals that an enhanced spin-phonon coupling originates from a negative pressure induced by uniform three-dimensional strain. Our work provides a route to creating multiferroicity and magnetoelectric coupling in single-phase oxides using a negative pressure approach.