Abstract
Anomalous paramagnetic effects in dc magnetization were observed in the mixed state of , unlike any reported previously. It appears as a kink-like feature for and becomes more prominent with increasing field. A specific heat anomaly at the corresponding temperature suggests that the magnetization anomaly is due to a true bulk transition. A magnetic flux transition from a square to an hexagonal lattice is consistent with the anomaly.
- Received 3 September 2004
DOI:https://doi.org/10.1103/PhysRevB.71.054511
©2005 American Physical Society