Thin-film alternating current nanocalorimeter for low temperatures and high magnetic fields

Journal Article · Fri Apr 01 04:00:00 EST 2005 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.1889432· OSTI ID:20646477

Minakov, A A; Roy, S B; Bugoslavsky, Y V; Cohen, L F ^[1]

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1. Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ (United Kingdom)

Thin-film nanocalorimeter for low temperatures and high magnetic fields is described. The calorimeter is based on a commercial microchip module (thermal conductivity vacuum gauge TCG 3880 from Xensor Integration, NL). The gauge consists of submicron silicon nitride membrane with a film-thermopile and a resistive film-heater with dimensions of 50x100 {mu}m{sup 2} located at the center of the membrane. The gauge is mounted in a thermostat filled with helium exchange gas. The method of alternating current (ac) calorimetry is applied for heat capacity measurements. The noise-floor sensitivity of the calorimeter is better than 1 nJ/K below 100 K and about 3 nJ/K at 300 K. This allows for reliable measurements to be performed on sub-microgram samples. It is proved that the method is applicable for heat capacity measurements at temperatures in the range of 5-300 K and in high magnetic fields up to 8 T. We present a theoretical analysis of the thermal processes in the gauge-sample-surrounding gas system. On this basis a calibration method has been developed. We demonstrate that the technique yields correct heat capacity for test samples and that in special cases the thermal conductivity and the magnetostriction of the sample can be measured simultaneously with the heat capacity.

• OSTI ID: 20646477
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 4 Vol. 76; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ALTERNATING CURRENT
CALIBRATION
CALORIMETERS
CALORIMETRY
HELIUM
MAGNETIC FIELDS
MAGNETOSTRICTION
MEMBRANES
NOISE
RELIABILITY
SENSITIVITY
SILICON NITRIDES
SPECIFIC HEAT
THERMAL CONDUCTIVITY
THERMOCOUPLES
THERMOSTATS
THIN FILMS
VACUUM GAGES