Room-temperature surface multiferroicity in Y2NiMnO6 nanorods

We report observation of surface-defect-induced room-temperature multiferroicity-surface ferromagnetism (M-S at 50 kOe approximate to 0.005 emu/g), ferroelectricity (P-R approximate to 2nC/cm(2)), and significantly large magnetoelectric coupling (decrease in P-R by approximate to 80% under approximate to 15 kOe field)-in nanorods (diameter approximate to 100 nm) of double perovskite Y2NiMnO6 compound. In bulk form, this system exhibits multiferroicity only below its magnetic transition temperature T-N approximate to 70 K. On the other hand, the oxygen vacancies, formed at the surface region (thickness approximate to 10 nm) of the nanorods, yield long-range magnetic order as well as ferroelectricity via Dzyloshinskii-Moriya exchange coupling interactions with strong Rashba spin-orbit coupling. Sharp drop in P-R under magnetic field indicates strong cross coupling between magnetism and ferroelectricity as well. Observation of room-temperature magnetoelectric coupling in nanoscale for a compound which, in bulk form, exhibits multiferroicity only below 70 K underscores an alternative pathway for inducing magnetoelectric multiferroicity via surface defects and, thus, in line with magnetoelectric property observed, for example, in domain walls or boundaries or interfaces of heteroepitaxially grown thin films which do not exhibit such features in their bulk.