This article describes the design and operation of a new
thermal analysis instrument which uses microwaves to simultaneously heat and detect thermally induced transformations in samples with masses in the range of 50 mg to 0.5 g. The data acquisition and control software developed for the instrument support a range of experimental techniques including constant power, linearly ramped power, linearly ramped temperature, and various modulated methods. Microwave thermal analysis utilizes the fact that physical or chemical alterations in a material, caused by processes such as melting, decomposition, or solid-solid phase changes, cause variations in its dielectric properties. These can be revealed by a variety of means including changes in the sample temperature, the differential temperature, or the shape of the power profile during linear heating experiments. The scope of the instrument is demonstrated with the decomposition of basic copper carbonate. The large temperature increase observed on the formation of the strongly coupling oxide indicates the potential sensitivity of using the thermal effects of dielectric changes as a means of detection. Further fine detail can be revealed by the use of derivative plots of either the applied power or the temperature.
- 1. E. Karmazsin, R. Barhoumi, and P. Satre, J. Therm. Anal. 29, 1269 (1984). Google Scholar
- 2. A. C. Metaxas and R. J. Meredith, Industrial Microwave Heating (Peter Perigrinus, London, 1983). Google Scholar
- 3. D. M. P. Mingosand D. R. Baghurst, Chem. Soc. Rev. 20, 1 (1991). Google Scholar
- 4. J. Dolandeand A. Datta, J. Microwave Power Electromagn. Energy 28, 58 (1993). Google Scholar
- 5. H. F. Huang, J. Microwave Power 11, 305 (1976). Google Scholar
- 6. S. Evansand J. Penfold, J. Microwave Power Electromagn. Energy 28, 84 (1993). Google Scholar
- 7. G. M. B. Parkes, P. A. Barnes, E. L. Charsley, and G. Bond, J. Therm. Anal. 56, 723 (1999). Google Scholar
- 8. M. Ravindran, P. Monsef-Mirzai, J. K. Maund, W. R. McWhinnie, and P. Burchill, J. Therm. Anal. 44, 25 (1995). Google Scholar
- 9. G. Bond, R. B. Moyes, S. A. Pollington, and D. A. Whan, Meas. Sci. Technol. 2, 571 (1991). Google Scholar
- 10. E. Karmazsin, R. Barhoumi, P. Satre, and F. Gaillard, J. Therm. Anal. 30, 43 (1985). Google Scholar
- 11. J. G. Zieglerand N. B. Nichols, J. Dyn. Syst., Meas., Control 115, 220 (1993). Google Scholar
- 12. G. M. B. Parkes, P. A. Barnes, E. L. Charsley, and G. Bond (unpublished). Google Scholar
- 13. G. M. B. Parkes, P. A. Barnes, E. L. Charsley, and G. Bond, Anal. Chem. (in press). Google Scholar
- 14. T. Labuzaand J. Meister, J. Microwave Power Electromagn. Energy 27, 205 (1992). Google Scholar
- 15. J. G. Binner, J. A. Fernie, and P. A. Whitaker, J. Mater. Sci. 33, 3009 (1998). Google Scholar
- 16. B. G. Ravi, P. D. Ramesh, N. Gupta, and R. J. Rao, J. Mater. Chem. 7, 2043 (1997). Google Scholar
- 17. N. N. Greenwood and A. Earnshaw, Chemistry of the Elements, 2nd ed. (Butterworth-Heinemann, Washington, DC, 1997). Google Scholar
- 18. P. Monsef-Mirzai, M. Ravindran, R. McWhinnie, and P. Burchill, Fuel 74, 20 (1995). Google Scholar
- 19. Z. D. Zivkovic, D. F. Bogosavljevic, and V. D. Zlalovic, Thermochim. Acta 18, 310 (1977). Google Scholar
- © 2000 American Institute of Physics.
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