Реферат: For arc-melted Al92Ce8 the comparison of crystalline and amorphous samples is carried out. Amorphous ribbon was obtained by quenching from 1580–1600 K using standard spinning technique at a wheel speed of 32 m/s. Ce L3-edge XANES and EXAFS experiments were performed on was studied using X-ray synchrotron radiation at the Structural Materials Science beamline [1] of the Kurchatov Synchrotron Radiation Center (Moscow, Russia). . X-ray diffraction (XRD) patterns were obtained in the transmission (Debye-Scherrer) geometry using a FujiFilm ImagingPlate 2D detector, λ = 0.68886 Å. XANES spectroscopy data gives significant fraction of tetravalent cerium 4f 0 (Ce4+) for both amorphous and crystalline states. The local structural parameters for crystalline state such as coordination number N=12.0±1 for Ce-atom and interatomic distance RAl–Ce =3.26 ± 0.02 Å are in excellent agreement with crystallographic data. The best result of the EXAFS fitting procedure for amorphous samples are given by Ce–Al distance that is rather short as compared with one obtained for crystalline samples (RAl–Ce = 3.23 ± 0.02 Å), while the coordination number around cerium is the same. This result contradicts to the prediction of the efficient atomic packing model, which suggests that the coordination number around rare earth atoms is about 17 [2]. Besides, no indication of the Ce atoms presence in the first coordination shell for both condensed phases was found. Acknowledgements:The work was partly supported by the Russian Foundation for Basic Research and the Government of Sverdlovsk region (grant nos 13-03-96055-ural and 13-02-96036-ural).The DSC and VSM experimental results were obtained using the instruments of the Collective Equipment Center “Ural-M”. References: [1] A.A. Chernyshov, A.A. Veligzhanin, Y.V. Zubavichus, Nucl. Instrum. Methods Phys.Res. A 603 (2009) 95–98 [2] R. Bacewicz, J. Antonowicz, Scr. Mater. 54 (2006) 1187–1191 [3] S. Uporov et al. / Journal of Non-Crystalline Solids 402 (2014)

Библиографическая ссылка: Uporov S. , Zubavichus Y. , Pryanichnikov S.
Local Chemical Order in Al92Ce8 Metallic Glass
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