| Autor: |
Ausloos, M., Pekala, M., Latuch, J., Mucha, J., Vanderbemden, Ph., Vertruyen, B., Cloots, R. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 12/15/2004, Vol. 96 Issue 12, p7338-7345, 8p, 1 Black and White Photograph, 1 Diagram, 6 Graphs |
| Abstrakt: |
Loosely packed granular materials are intensively studied nowadays. Electrical and thermal transport properties should reflect the granular structure, as well as intrinsic properties. We have compacted crystalline CaAl-based metallic grains and studied the electrical resistivity and the thermoelectric power as a function of temperature (T) from 15 to 300 K. Both properties show three regimes as a function of temperature. It should be pointed out: (i) The electrical resistivity continuously decreases between 15 and 235 K, (ii) with various dependencies, e.g., ≃T-3/4 at low T, while (iii) the thermoelectric power (TEP) is positive, (iv) shows a bump near 60 K, and (v) presents a rather unusual square root of temperature dependence at low temperature. It is argued that these three regimes indicate a competition between geometric and thermal processes—for which a theory seems to be missing in the case of TEP. The microchemical analysis results are also reported, indicating a complex microstructure inherent to the phase diagram peritectic intricacies of this binary alloy. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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