Ultrasound velocity and attenuation of liquid in aerogel

Autor:	Koichi Matsumoto, Koji Tajiri, Yoshihiro Matsuyama, Tomomasa Higaki
Rok vydání:	2003
Předmět:	Materials science business.industry Transition temperature Attenuation Composite number Aerogel Condensed Matter Physics Electronic Optical and Magnetic Materials Superfluidity Optics Phase (matter) Electrical and Electronic Engineering Composite material business Porosity Acoustic attenuation
Zdroj:	Physica B: Condensed Matter. :335-336
ISSN:	0921-4526
DOI:	10.1016/s0921-4526(02)02078-1
Popis:	The ultrasound velocity and attenuation of liquid 4 He in various porosity aerogels were measured for a frequency of 10 MHz . The superfluid transition temperature was suppressed by aerogel which was determined as a dip of sound velocity and a attenuation peak. Sound velocity in this composite system depended seriously on the aerogel porosity. An aerogel- 4 He composite model, in which normal fluid was clamped to aerogel strand gave almost satisfactory temperature and aerogel porosity dependence of the sound velocity. The sound attenuation in aerogel was considerably larger than that in bulk liquid. That in the normal phase had small porosity dependence. However, that in the superfluid phase decreased with decreasing temperature and became constant at low temperatures. The attenuation peak ascribed to roton–phonon interaction was not observed in aerogel- 4 He system.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::fe956b177161349effeb1e66cf20d94f https://doi.org/10.1016/s0921-4526(02)02078-1 Zobrazit plný text záznamu Full Text from ScienceDirect