We have measured the temperature dependence of the velocity and the attenuation of sound in the range 60-700 mK. The maximum in the sound velocity observed by Abraham and Osborne is confirmed. The viscosity deduced from the attenuation measurements is in good agreement with that of Abel, Anderson, and Wheatley but differs from that of Betts, Keen, and Wilks. The sound velocity as a function of pressure at 150 mK was also measured and from this the low-temperature pressure dependence of the density was determined.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Materials Science(all)
- Condensed Matter Physics