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Thermoelectrical Properties Of Covetics, S. M. Sarif Rana
Thermoelectrical Properties Of Covetics, S. M. Sarif Rana
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Covetics are hybrid materials fabricated by fusing carbon with metals in an induction furnace. There is an indication that covetics have better thermal and electrical proper-ties in comparison with pure metals. The main goal of this research is to study thermal transport in covetics measured by specific absorption rate using calorimetry. In addition, temperature distribution has been measured along the both metal and covetic wires carrying currents of 5 A and 10 A, respectively. The first set of copper covetic (Cu cov) samples with nominal content of 36 at% carbon were prepared by Third Millennium Materials Company (TMMC) in the …
Temperature And Frequency Dependent Conduction Mechanisms Within Bulk Carbon Nanotube Materials, John Simmons Bulmer
Temperature And Frequency Dependent Conduction Mechanisms Within Bulk Carbon Nanotube Materials, John Simmons Bulmer
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The resistance of three types of bulk carbon nanotube (CNT) materials (floating catalyst CNT yarn, forest grown CNT yarn, and super acid spun CNT fiber) was measured from room temperature to 900 C. Fitting the curves to established conduction equations for disordered materials, competing conduction mechanisms pertaining to the material could be determined. Floating catalyst CNT yarn displayed both semiconductive and metallic isotropic behavior with a resistance minimum, similar to the behavior of crystalline graphite. It was found that, at room temperature, the semiconducting contribution-most likely junctions between CNTs-accounted for 99.99% of the overall resistance. The resistance of forest grown …