Re-Entrant Spin Glass Behavior In Mn-Rich Ymno3

We use magnetism and specific heat measurements to investigate the hexagonal Mn-rich YMnO3. It is found that upon cooling from a high temperature, the compound first orders antiferromagnetically at T-N similar to 72 K and then undergoes a re-entrant spin glass (RSG) transition at T-SG similar to 42 K. This RSG behavior results from the competition between the ferromagnetic interaction and the antiferromagnetic interaction, which is related to the intrinsic geometric magnetic frustration in this system. (c) 2005 American Institute of Physics.