Molar-volume dependence of the pressure in hcp solid 3He in magnetic fields

Pressure measurements have been made in a hcp solid He-3 at molar volumes from 18.90 to 19.45 cm(3)/mol, at temperatures down to 1 mK and in magnetic fields up to 0.16 Tesla. The results are analyzed by a high-temperature series expansion with multiple-exchange processes. The molar volume dependence of the multiple-exchange interactions has been determined by pressure measurements in magnetic fields. The results indicate that the exchange frequencies determined by the pressure measurements in a hcp solid He-3 are consistent with those obtained by magnetization measurements.