Specific heat of Mn0.5Zn0.5F2in random fields

Abstract

The author reports high-precision measurements of the specific heat of a diluted antiferromagnet, Mn0.5Zn0.5F2, in a magnetic field. In zero field, a sharp peak at the Neel temperature is seen. When a magnetic field is applied along the spin's easy axis, it exhibits a random-field Ising model behaviour. The shape of the specific heat peak shows continuous broadening with increasing field, and no hysteretic behaviours are observed within experimental accuracy. In higher fields, a sharp peak is observed at the temperature corresponding to the transition from the paramagnetic to the spin-flop phase.