PRECISE MAGNETIC PHASE-DIAGRAM OF BCC HE-3 FOCUSING ON THE TRIPLE POINT

The magnetic phase diagram of bcc solid He-3 at V = 24.18 cm3/mole was determined from isochoric pressure measurements at temperatures down to 350 muK in magnetic fields up to 0.46 T. It shows a sharp kink at the triple point along the low-field phase boundary, indicating that the transition between the high-field and paramagnetic phases (H - P) is first order near the triple point. We also observed the pressure change at the H - P transition, supporting the above conclusion.