THERMODYNAMIC PROPERTIES OF BCC SOLID HE-3 NEAR THE ORDERING TRANSITIONS

The melting pressure of magnetically ordered solid He-3 near the LFP-P P, HFP-PP and LFP-HFP transitions has been measured in various fields. The entropy in each phase and the discontinuity across the transition are obtained from dP/dT. In the LFP, we find a weak field-dependence of the entropy. This indicates that the magnetization is almost temper ature-independent. The entropy discontinuity, DELTAS/Rln2, at the LFP- PP transition changes from 0.42 for B=0 to 0.38 for B=0.39T. The magne tization discontinuity across the LFP-PP phase boundary, DELTAM/M(sat) , obtained from DELTAS and the slope dTn/dB, is found to be proportion al to the magnetic field. The measurements are also extended to LFP-HF P and HFP-PP transitions.