Ordered Three‐Dimensional Arrays of Monodispersed Mn3O4 Nanoparticles with a Core–Shell Structure and Spin‐Glass Behavior

Don't forget your coat! Monodispersed Mn3O4 nanoparticles, each encased in a thin shell of MnO2, have been prepared for the first time. Ordered three-dimensional arrays of cubic symmetry were formed by self-assembly (see transmission electron microscope image). The nanoparticles exhibit strong interactions between the core and shell, resulting in spin-glass behavior.