Coexistence of superfluid and solid helium in aerogel
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The results of recent neutron scattering studies of solid helium in silica aerogel are discussed. Previously I.V. Kalinin et al., Pis’ma Zh. Éksp. Teor. Fiz. 87 (1), 743 (2008) [JETP Lett. 87 (1), 645 (2008)], we detected the existence of a superfluid phase in solid helium at a temperature below 0.6 K and a pressure of 51 bar, although, according to the phase diagram, helium should be in the solid state under these conditions. This work is a continuation of the above studies whose main goal was to examine the detected phenomenon and to establish basic parameters of the existence of a superfluid phase. We have determined the temperature of the superfluid transition from solid to superfluid helium, T C = 1.3 K, by analyzing experimental data. The superfluid phase excitation parameters (lifetime, intensity, and energy) have a temperature dependence similar to that of bulk helium. The superfluid phase coexists with the solid phase in the entire measured temperature range from T = 0.05 K to T C and is a nonequilibrium one and disappears at T C.
KeywordsDispersion Curve Kalinin Helium Atom Silica Aerogel Superfluid Helium
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- 1.I. V. Kalinin, E. I. Kats, M. Koza, V. V. Lauter, Kh. Lauter, and A. V. Puchkov, Pis’ma Zh. Éksp. Teor. Fiz. 87(11), 743 (2008) [JETP Lett. 87 (11), 645 (2008)].Google Scholar
- 3.L. D. Landau, J. Phys. (Moscow) 11, 91 (1947).Google Scholar
- 5.A. F. Andreev and I. M. Lifshitz, Zh. Éksp. Teor. Fiz. 56(6), 2057 (1969) [Sov. Phys. JETP 29 (6), 1107 (1969)].Google Scholar
- 7.I. V. Kalinin, M. Koza, H. Lauter, V. V. Lauter-Pasyuk, and A. V. Puchkov, Kristallografiya 52(3), 505 (2007) [Crystallogr. Rep. 52 (3), 566 (2007)].Google Scholar
- 10.B. N. Esel’son, L. A. Pogorelov, and V. I. Sobolev, Ukr. Fiz. Zh. 19, 763 (1974).Google Scholar