Room-temperature ferromagnetism and ferroelectricity in Fe-dopedBaTiO3

We report the ferroelectricity and ferromagnetism coexistence in the Fe-doped ${\text{BaTiO}}_3$. Our first-principles calculation based on the density-functional theory predicted a magnetic moment of $3.05{\mu }_B$ per Fe atom when Fe substitutes Ti in ${\text{BaTiO}}_3$, and a ferromagnetic coupling among the magnetic moments of the Fe dopants by using $\text{LSDA}+U$ method. The theoretical prediction was confirmed experimentally. The Fe-doped ${\text{BaTiO}}_3$ ceramics prepared by the solid-state-reaction method show simultaneously the ferromagnetic order with the magnetic transition temperature over 680 K and the ferroelectric order with the dielectric transition temperature about 365 K, respectively. The measured magnetic moment about $0.75{\mu }_B/\text{Fe}$ atom was smaller than that of the theoretical prediction, and the remnant polarization 2 Pr is about $22.2\mu \text{C}/{\text{cm}}^2$.