NMR and third sound studies of dilute sup 3 He- sup 4 He mixture films

Thesis/Dissertation · Fri Jan 01 00:00:00 EST 1988

OSTI ID:5468886

Valles, Jr, J M

Results of a series of simultaneous third sound and NMR measurements on dilute {sup 3}He-{sup 4}He mixture films adsorbed on Nuclepore at dilution refrigerator temperatures are reported. The third sound speed and dissipation measurements were carried out using a resonator constructed from a single sheet of Nuclepore. The nuclear magnetic susceptibility of the {sup 3}He, and the NMR relaxation times, T{sub 2} and T{sup 1} were measured using pulsed NMR techniques in a 2-Tesla field. Mixture films in the coverage range 0 {le} d{sub 3} {le} 0.44 monolayers and 2.8 {le} d{sub 4} {le} 9.5 layers were investigated where d{sub 3} is the {sup 3}He coverage in terms of bulk {sup 3}He liquid layers and d{sub 4} is the thickness of the {sup 4}He film in bulk {sup 4}He liquid layers. Measurements are presented of the fractional change in the square of the third sound speed, {gamma}C{sup 2}{sub 3}, following the addition of small amounts of {sup 3}He to a {sup 4}He film. For d{sub 4} = 2.8 layers and 0 {le} d{sub 3} {le} 0.088 layers {gamma}C{sub 3}{sup 2} is a linear function of d{sub 3} consistent with the Lekner formulation of the mixture film problem. For d{sub 3} = 0.088 layers and 2.8 < d{sub 4} < 5.3 layers {gamma}C{sub 3}{sup 2}/d{sub 3} has an unexpected minimum as a function of d{sub 4}. Comparisons to {gamma}C{sub 3}{sup 2}/d{sub 3} on glass are made. Measurements of the nuclear magnetic susceptibility, {chi}, of the {sup 3}He in these mixture films as a function of d{sub 3} are presented.

• Research Organization: Massachusetts Univ., Amherst, MA (USA)
• OSTI ID: 5468886
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
HELIUM 3
THIN FILMS
HELIUM 4
NUCLEAR MAGNETIC RESONANCE
RELAXATION TIME
SUPERFLUIDITY
THIRD SOUND
MAGNETIC SUSCEPTIBILITY
MIXTURES
DISPERSIONS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FILMS
HELIUM ISOTOPES
ISOTOPES
LIGHT NUCLEI
MAGNETIC PROPERTIES
MAGNETIC RESONANCE
NUCLEI
PHYSICAL PROPERTIES
RESONANCE
STABLE ISOTOPES
640450* - Fluid Physics- Superfluidity
640460 - Fluid Physics- Other Quantum Fluids