Sensitive power compensated scanning calorimeter for analysis of phase transformations in small samples

Journal Article · Wed Jun 15 04:00:00 EDT 2005 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.1921567· OSTI ID:20722919

Lopeandia, A F; Cerdo, Ll; Clavaguera-Mora, M T; Arana, Leonel R; Jensen, K F; Munoz, F J; Rodriguez-Viejo, J ^[1]

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1. Grupo de Fisica de Materiales I. Department de Fisica, Universidad Autonoma de Barcelona, 08193 Bellaterra (Spain)

We have designed and developed a sensitive scanning calorimeter for use with microgram or submicrogram, thin film, or powder samples. Semiconductor processing techniques are used to fabricate membrane based microreactors with a small heat capacity of the addenda, 120 nJ/K at room temperature. At heating rates below 10 K/s the heat released or absorbed by the sample during a given transformation is compensated through a resistive Pt heater by a digital controller so that the calorimeter works as a power compensated device. Its use and dynamic sensitivity is demonstrated by analyzing the melting behavior of thin films of indium and high density polyethylene. Melting enthalpies in the range of 40-250 {mu}J for sample masses on the order of 1.5 {mu}g have been measured with accuracy better than 5% at heating rates {approx}0.2 K/s. The signal-to-noise ratio, limited by the electronic setup, is 200 nW.

• OSTI ID: 20722919
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 6 Vol. 76; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACCURACY
CALORIMETERS
DENSITY
ENTHALPY
HEAT
HEATERS
HEATING RATE
INDIUM
MELTING
POLYETHYLENES
SEMICONDUCTOR MATERIALS
SENSITIVITY
SIGNAL-TO-NOISE RATIO
SPECIFIC HEAT
TEMPERATURE RANGE 0273-0400 K
THIN FILMS