Comparison between Torsional Oscillator and Ultrasonic Measurements of 4He Confined in Nano-Porous Media
- 25 Downloads
We have performed torsional oscillator and ultrasonic measurements for 4He confined in 2D nano-porous substrate, hectorite. For 4He films, the resonance frequency of the torsional oscillator increases rapidly just below a superfluid transition temperature (T C ), and then becomes constant at the lower temperature. In contrast, the sound velocity below T C increases monotonically with decreasing temperature. For liquid 4He the sound velocity has a small bend at T b of about 0.9 K. Its increase below T b is enhanced as the pressure is increased.
KeywordsSound Velocity Areal Density Torsional Oscillator Ultrasonic Measurement Solid Layer
Unable to display preview. Download preview PDF.
- 2.T. Kobayashi, S. Fukazawa, J. Taniguchi, M. Suzuki, K. Shirahama, in AIP Conference Proceedings, vol. 850 (Am. Inst. Phys., Melville, 2006), p. 277. Google Scholar
- 3.K. Torii, T. Iwasaki, Y. Onodera, K. Hatanaka, Chemistry of Microporous Crystals (Kodansya, Tokyo, 1991), p. 81 Google Scholar
- 4.Hectorite PW-1 used in the present experiments was synthesized under the same condition as that of hectorite OH-02 used in the experiments of Wada et al. Google Scholar