Research Papers in Physics and Astronomy


Date of this Version



Published by American Physical Society. Phys. Rev. B 75, 134423 2007. Copyright © 2007 American Physical Society. Permission to use.


Nanoparticles of bulk antiferromagnets often exhibit ferromagnetic behavior due to uncompensated surface spins. The peak temperature in the zero-field-cooled magnetization of MnO—in contrast to other antiferromagnetic nanoparticles—has anomalous behavior, shifting to higher temperatures with decreasing nanoparticle size. We attribute this behavior to surface anisotropy enhanced by the specific occupancy of 3d levels in Mn, which produces a high-spin–low-spin transition not present in NiO nanoparticles.

Included in

Physics Commons