CO 2 -Induced Spin-Lattice Coupling for Strong Magnetoelectric Materials.

The preparation of 2D magnetoelectric (ME) nanomaterials with strong ME coupling is crucial for the fast reading and writing processes in the next generation of storage devices. Herein, 2D BaTiO 3 (BTO)-CoFe 2 O 4 (CFO) ME nanocomposites are prepared through a substrate-free coupling strategy using supercritical CO 2 . Such 2D BTO-CFO with strong coupling is built through alternating in-plane and out-of-plane epitaxy stacking, leading to remarkable mutual biaxial strain effects for spin-lattice coupling. As a results, such strain effect significantly enhances the ferroelectricity of BTO and the ferrimagnetism of CFO, where an unexceptionally high ME coupling coefficient of (325.8 mV cm -1  Oe -1 ) is obtained for the BTO-CFO nanocomposites.