Critical properties of [sup 4]He in aerogel near the [lambda]-line

Conference · Thu Oct 01 00:00:00 EDT 1992 · Journal of Low Temperature Physics; (United States)

OSTI ID:7173970

Larson, M; Mulders, N; Mehrotra, R; Goldner, L S; Ahlers, G ^[1]

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1. Univ. of California, Santa Barbara (United States)

The authors measured the superfluid fraction [rho][sub s]/[rho] and the isobaric thermal expansion coefficient [beta][sub P] of [sup 4]He confined in an aerogel. Data were obtained near the [lambda]-line along several isobars. Powerlaw fits to the results for [rho][sub s]/[rho] as a function of t [equivalent to] T/[Tc] [minus] 1 ([Tc] is the transition temperature) give a pressure-independent exponent [zeta] = 0.755 when a confluent singular term is included. Fits to the [beta][sub P] data of power laws yield the specific-heat exponents [alpha] [congruent] [minus]0.6 and [alpha][prime] [congruent] [minus]1.0 [ne] [alpha] above and below [Tc], respectively. When an analytic background term a [times] t is included in the fit, the pressure-independent value [alpha] = [alpha][prime] [congruent] [minus]0.59 is permitted, but the amplitude ratio [Alpha][prime]/[Alpha] is found to be near zero and the coefficient of the analytic term is large. The measured values for [zeta] and [alpha][prime] or [alpha] are inconsistent with hyperscaling in three dimensions.

• OSTI ID: 7173970
• Report Number(s): CONF-9206305-Pt.1; CODEN: JLTPAC; TRN: 92-037910
• Journal Information: Journal of Low Temperature Physics; (United States), Vol. 89:1-2; Conference: Symposium on quantum fluids and solids, University Park, PA (United States), 15-19 Jun 1992; ISSN 0022-2291
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
HELIUM 4
ADSORPTION
SUPERFLUIDITY
THERMAL EXPANSION
SILICA GEL
SORPTIVE PROPERTIES
LAMBDA POINT
PHASE TRANSFORMATIONS
POROUS MATERIALS
TRANSITION TEMPERATURE
ADSORBENTS
EVEN-EVEN NUCLEI
EXPANSION
HELIUM ISOTOPES
ISOTOPES
LIGHT NUCLEI
MATERIALS
NUCLEI
PHYSICAL PROPERTIES
SORPTION
STABLE ISOTOPES
SURFACE PROPERTIES
THERMODYNAMIC PROPERTIES
665420* - Superfluidity- (1992-)