The mechanical relaxation study of polycrystalline MgC1 xNi3
| Autor: | Hai-Hu Wen, J. W. Ding, X. N. Ying, Guang-Can Che, Zhi-An Ren, Y. X. Yao, Z.X. Zhao, Y. N. Wang, Ya Huang |
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| Rok vydání: | 2004 |
| Předmět: |
Superconductivity
Materials science Condensed matter physics Relaxation (NMR) Metals and Alloys chemistry.chemical_element Activation energy Liquid nitrogen Condensed Matter Physics Spectral line chemistry Position (vector) Materials Chemistry Ceramics and Composites Crystallite Electrical and Electronic Engineering Carbon |
| Zdroj: | Superconductor Science and Technology. 17:608-611 |
| ISSN: | 1361-6668 0953-2048 |
| DOI: | 10.1088/0953-2048/17/4/007 |
| Popis: | The mechanical relaxation spectra of a superconducting and a non-superconducting MgCNi3 samples were measured from liquid nitrogen temperature to room temperature at frequency of kilohertz. There are two internal friction peaks (at 300 K labeled as P1 and 125 K as P2) for the superconducting sample. For the non-superconducting one, the position of P1 shifts to 250 K, while P2 is almost completely depressed. It is found that the peak position of P2 shifts towards higher temperature under higher measuring frequency. The calculated activation energy is 0.13eV. We propose an explanation relating P2 to the carbon atom jumping among the off-center positions. And further we expect that the behaviors of carbon atoms maybe correspond to the normal state crossovers around 150 K and 50 K observed by many other experiments. |
| Databáze: | OpenAIRE |
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