Sensitive power compensated scanning calorimeter for analysis of phase transformations in small samples
- 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, Vol. 76, Issue 6; Other Information: DOI: 10.1063/1.1921567; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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