ac calorimeter for measurements of adsorbed gases on metal films at sup 4 He temperatures

Journal Article · Thu Feb 01 04:00:00 EST 1990 · Review of Scientific Instruments; (USA)

DOI:https://doi.org/10.1063/1.1141501· OSTI ID:7069506

Kenny, T W; Richards, P L ^[1]

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1. Department of Physics, University of California, Berkeley, CA (USA) Materials and Chemical Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (USA)

An analysis is presented of the performance of an ideal ac calorimeter limited only by thermodynamic noise. A calorimeter based on this analysis is described which is designed for studies of the heat capacity of monolayers and multilayers of atoms and molecules adsorbed on a variety of surfaces. The calorimeter consists of Ge:Ga thermometers and NiCr heaters mounted on one side of a sapphire substrate, with an evaporated film deposited on the other side. The calorimeter is mounted on a {sup 4}He cold finger in a UHV system allowing heat capacity measurements down to 1.6 K. In order to verify the performance of the calorimeter, measurements have been made of the heat capacity of 25-{mu}g samples of indium, and of submonolayer coverages of {sup 4}He on sapphire. The measured sensitivity corresponds to {lt}10{sup {minus}2} monolayers of {sup 4}He adsorbed on the surface of the calorimeter in the gas phase.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 7069506
• Journal Information: Review of Scientific Instruments; (USA), Journal Name: Review of Scientific Instruments; (USA) Vol. 61:2; ISSN RSINA; ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

440500* -- Thermal Instrumentation-- (1990-)
47 OTHER INSTRUMENTATION
ADSORPTION
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CALORIMETERS
CHALCOGENIDES
CORUNDUM
DESIGN
ELEMENTS
EVEN-EVEN NUCLEI
HELIUM 4
HELIUM ISOTOPES
INDIUM
ISOTOPES
LIGHT NUCLEI
MEASURING INSTRUMENTS
METALS
MINERALS
NUCLEI
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE
PHYSICAL PROPERTIES
SAPPHIRE
SORPTION
SPECIFIC HEAT
STABLE ISOTOPES
SUBSTRATES
THERMODYNAMIC PROPERTIES
THERMOMETERS
ULTRALOW TEMPERATURE