Abstract
Order-disorder transition is observed in the quasi-one-dimensional anisotropic spin chain antiferromagnet in magnetic fields along the magnetic easy axis below the Néel temperature. We construct the phase diagram in the plane through magnetic and heat capacity measurements and find that the phase boundary of the order-disorder transition can be described in terms of a mean-field power law. We also suggest that quantum critical behavior from three-dimensional Néel ordering back into a one-dimensional disordered phase is observed in magnetic fields above a critical value of .
- Received 28 June 2005
DOI:https://doi.org/10.1103/PhysRevB.72.172403
©2005 American Physical Society