What's New Research & Study Equipments         Published the APL Paper. : 2009.01.22 : Published the APL Paper. Strain-induced magnetoelectric coupling in BaTiO3/Fe3O4 core/shell nanoparticles We report a strain-induced magnetoelectric coupling in BaTiO3/Fe3O4 ferroelectric core/ferrimagnetic shell nanoparticles. The temperature-dependent magnetoresistance and magnetization clearly show several jumps near the structural phase transition temperatures of BaTiO3. Below the Verwey transition temperature of Fe3O4, i.e., at 20 K, the dielectric constant of BaTiO3/Fe3O4 decreases continuously upon application of an external magnetic field, and the observed magnetodielectric curve does not follow the square of the magnetization. We discuss the effect of strain on the electric field-dependent magnetic anisotropy near the core/shell interface. Published the PRB paper Interface electronic structure of BaTiO3@X nanoparticles (X=g-Fe2O3, Fe3O4, a-Fe2O3, and Fe) investigated by XAS and XMCD The electronic structures of BaTiO3@X (core@shell) nanoparticles (X=gamma-Fe2O3, Fe3O4, and Fe) have been investigated by employing soft x-ray-absorption spectroscopy and x-ray magnetic circular dichroism (XMCD). It is found that the valence states of Ti ions near interfaces are formally tetravalent (Ti4+:3d0) and that the valence states of Fe ions in shells are essentially the same as those of the corresponding bulk materials, with some disorder in the site occupations for X=gamma-Fe2O3 and Fe3O4. The negligible Ti2p XMCD signals were observed, indicating that the induced spin polarization of the interface Ti3d electrons is negligible in BaTiO3@X nanoparticles.