School of Materials Science and Chemical Engineering;
Ningbo University;
Ningbo 315211;
China;
CAS Key Laboratory of Magnetic Materials and Devices;
Ningbo Institute of Material Technology and Engineering;
Chinese Academy of Sciences;
Ningbo 315201;
China;
Institute of Materials;
Shanghai University;
Shanghai 200444;
China;
In situ TEM; Fe3O4–Ag heterodimer; Nanoparticle; Janus structure; Interface;