| Autor: |
Chengkai Luan, Xiyue Cheng, Xiuping Gao, Jürgen Köhler, Shuiquan Deng |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
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| Zdroj: |
Molecules, Vol 28, Iss 18, p 6455 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
1420-3049 |
| DOI: |
10.3390/molecules28186455 |
| Popis: |
The Nb3Al superconductor with excellent physical and working properties is one of the most promising materials in high-magnetic-field applications. However, it is difficult to prepare high-quality Nb3Al with a desired superconducting transition temperature (Tc) because of its narrow phase formation area at high temperatures (>1940 °C). This work reports a method to prepare stoichiometric Nb3Al powder samples at a relatively low temperature (1400 °C) by exploiting the nano effect of Nb particles with pretreatment of Nb powder under H2/Ar atmosphere. The obtained Nb3Al samples exhibit high Tc’s of ~16.8K. Based on density functional theory (DFT) calculations and statistical mechanics analysis, the crucial role of quantum effect in leading to the success of the preparation method was studied. A new measure of surface energy (MSE) of a model particle is introduced to study its size and face dependence. A rapid convergence of the MSE with respect to the size indicates a quick approach to the solid limit, while the face dependence of MSE reveals a liquid-like behavior. The surface effect and quantum fluctuation of the Nbn clusters explain the success of the preparation method. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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