27Al, 63Cu NMR spectroscopy and electrical transport in Heusler Cu–Mn–Al alloy powders
| Autor: | S. M. Konoplyuk, V. V. Trachevskii, A. O. Perekos, V.V. Kokorin, V. M. Nadutov, D. L. Vashchuk |
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| Rok vydání: | 2018 |
| Předmět: |
010302 applied physics
Materials science Materials Science (miscellaneous) Alloy Pellets Analytical chemistry Nanoparticle 02 engineering and technology Cell Biology Nuclear magnetic resonance spectroscopy engineering.material 021001 nanoscience & nanotechnology 01 natural sciences Atomic and Molecular Physics and Optics NMR spectra database Electrical resistance and conductance Electrical resistivity and conductivity 0103 physical sciences engineering Electrical and Electronic Engineering Physical and Theoretical Chemistry 0210 nano-technology Saturation (magnetic) Biotechnology |
| Zdroj: | Applied Nanoscience. 8:965-971 |
| ISSN: | 2190-5517 2190-5509 |
| Popis: | The ultrafine powder of the Heusler Cu-13,1Mn-12,6Al (wt.%) alloy produced by electrical spark dispersion (ESD) in ethanol and the pellets prepared by pressing of the powders and aged in various gas environment (air, Ar, vacuum) were studied by XRD, nuclear magnetic resonance, magnetic and electric transport methods. The constituent phases were identified as b.c.c. α–Cu–Mn–Al, f.c.c. γ-Cu–Mn–Al, Cu2MnAl, and oxides. The sizes of the coherently scattering domains (CSD) and the saturation magnetizations were in the range of 4–90 nm and 0–1.5 Am2/kg, respectively. 27Al and 63Cu NMR spectra of the powders and pellets have shown hyperfine structure caused by contributions from atomic nuclei of the constituent phases. The aging of pellets in different gas environments had effect on their phase composition but no effect on dispersion of the phases. In contrast to the as-cast alloy, electrical resistance of the pellets evidenced semiconducting behavior at elevated temperatures due to the presence of metal oxides formed on the surfaces of nanoparticles. |
| Databáze: | OpenAIRE |
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