Designed ferromagnetic, ferroelectric Bi2NiMnO6

A newly designed ferromagnetic, ferroelectric compound, Bi2NiMnO6, was prepared by highpressure synthesis at 6 GPa. The crystal structure, as determined by synchrotron X-ray powder diffraction, is a heavily distorted double perovskite with Ni2+ and Mn4+ ions ordered in a rock-salt configuration. The presence of 6s(2) lone pairs of Bi3+ ions and the covalent Bi-O bonds give ferroelectric properties with T-CE of 485 K, while -Ni2+-O- Mn4+-O-Ni2+- magnetic paths lead to a ferromagnetism with T-CM of 140 K. This simple material design to distribute two magnetic elements with and without e(g) electrons on B sites of Bi- and Pb-based perovkites can be applied to other Bi2M2+M-'4+O-6 and Pb2M3+ M'5+O6 systems to search for newer ferromagnetic ferroelectrics.