Abstract
Based on first-principles calculations on BaTcO3, we explored a route to promoting ferroelectricity by non-d0 cation B in magnetic perovskites, leading to the co-existence of magnetic and dielectric ordering in a single phase. The ground state of the perovskite BaTcO3 was found to be an insulator with G-type antiferromagnetic order. A tensile strain in BaTcO3 not only inverted the lowest unoccupied states dominated from t2g to eg, driving the ferroelectric distortion, but also enlarged this driven force due to the induced narrower gap as its divisor. The tensile strain simultaneously weakened the repulsive force when Tc distorted to one apex of the O-octahedron in BaTcO3. Most importantly, since the physics of our finding is not Tc specific, the route is generally applicable to other magnetic perovskites.