Shell pressure on the core of MnO/Mn3O4 core/shell nanoparticles.

Here we show that spontaneous oxidation of MnO nanoparticles into MnO/Mn3O4 core/shell nanoparticles has the effect of a local pressure, decreasing the MnO cell parameter and increasing strain, resulting in the increase of the MnO antiferromagnetic/paramagnetic transition temperature TN. These effects are more severe in smaller nanoparticles. [ABSTRACT FROM AUTHOR]