UC Berkeley

Monte Carlo simulations show that the net magnetization of collinear antiferromagnets (AFM) with uncompensated surfaces exhibits a unique thermodynamic behavior, with a temperature dependence unlike that of ferromagnets or of the Néel vector. The magnetization of AFM is not equal to that of its surface, even though it results from surface effects. This phenomenon appears in thin AFM films but is valid even in the limit of semi-infinite systems. The net magnetization of AFM therefore corresponds to a distinct topological thermodynamic state due to the free surface. © CopyrightEPLA, 2014.