Structural and Dynamical Changes in a Gd-Co Metallic Glass by Cryogenic Rejuvenation

Shinya Hosokawa; Jens R. Stellhorn; Laszlo Pusztai; Yoshikatsu Yamazaki; Jing Jiang; Hidemi Kato; Tetsu Ichitsubo; Eisuke Magome; Nils Blanc; Nathalie Boudet; Koji Ohara; Satoshi Tsutsui; Hiroshi Uchiyama; Alfred Q. R. Baron

arXiv · 2311.04422

Structural and Dynamical Changes in a Gd-Co Metallic Glass by Cryogenic Rejuvenation

Shinya Hosokawa·Jens R. Stellhorn·Laszlo Pusztai·Yoshikatsu Yamazaki·Jing Jiang·Hidemi Kato·Tetsu Ichitsubo·Eisuke Magome·Nils Blanc·Nathalie Boudet·Koji Ohara·Satoshi Tsutsui·Hiroshi Uchiyama·Alfred Q. R. Baron

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Abstract

To experimentally clarify the changes in structural and dynamic heterogeneities in a metallic glass (MG), Gd65Co35, by rejuvenation with a temperature cycling (cryogenic rejuvenation), high-energy x-ray diffraction (HEXRD), anomalous x-ray scattering (AXS), and inelastic x-ray scattering (IXS) experiments were carried out. By a repeated temperature change between liquid N2 and room temperatures 40 times, tiny but clear structural changes are observed by HEXRD even in the first neighboring range. Partial structural information obtained by AXS reveals that slight movements of the Gd and Co atoms occur in the first- and second-neighboring shells around the central Gd atom. The concentration inhomogeneity in the nm size drastically increases for the Gd atoms by the temperature cycling, while the other heterogeneities are negligible. A distinct change was detected in a microscopic elastic property by IXS: The width of longitudinal acoustic excitation broadens by about 20%, indicating an increase of the elastic heterogeneity of this MG by the thermal treatments. These static and dynamic results explicitly clarify the features of the cryogenic rejuvenation effect experimentally.

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Shinya Hosokawa, Jens R. Stellhorn, Laszlo Pusztai, Yoshikatsu Yamazaki, Jing Jiang, Hidemi Kato, Tetsu Ichitsubo, Eisuke Magome, Nils Blanc, Nathalie Boudet, Koji Ohara, Satoshi Tsutsui, Hiroshi Uchiyama, Alfred Q. R. Baron. 2023-11-08. Structural and Dynamical Changes in a Gd-Co Metallic Glass by Cryogenic Rejuvenation. https://arxiv.org/abs/2311.04422

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