Abstract
We report pulsed magnetization and NMR studies of a quantum phase transition and its associated spin dynamics in a system, using the alkali-metal peroxychromate . This is an example of a -based and material with a clearly defined in zero applied field . Its magnetization shows a nonlinear increase with , in contrast to a simple three-dimensional antiferromagnet, and saturates at . This easily accessible allows for a detailed study by NMR of the magnetic-field-induced quantum phase transition from the antiferromagnetically ordered to a ferromagnetically polarized phase. The critical exponent of is at but shows a definitive increase to at 6.8 T, close to . This suggests that while the magnetic behavior of is largely describable by a mean-field theory, the field dependence of remains unexplained.
3 More- Received 15 September 2008
DOI:https://doi.org/10.1103/PhysRevB.78.214419
©2008 American Physical Society