CRITICAL-BEHAVIOR OF THERMAL PARAMETERS OF FEF2 AT THE NEEL TEMPERATURE

A photopyroelectric technique has been applied to the study of the cri tical behaviour of thermal parameters. Critical exponents of 0.11 and -0.11 have been found for the specific heat and the thermal diffusivit y, respectively. These results show that the dynamic critical behaviou r of the system can be described in terms of a model with non-conserve d order parameter and energy conservation of the spin system. The beha viour of the thermal conductivity in the vicinity of the transition te mperature is also reported.