Abstract
To understand the relation of the glass-forming ability (GFA) to the local atomic configurations of a
Pd42.5Ni7.5Cu30P20 (PNCP) metallic glass having the best GFA at present, the local structures were investigated by
combining data obtained from anomalous X-ray scattering, X-ray and neutron diffraction, and applying reverse Monte Carlo modeling. By comparing the results of PNCP with Pd40Ni40P20 (PNP) and Pd40Cu40P20 (PCP) having a slightly and much worse GFAs, respectively, characteristic features were observed in the hyper-ordered atomic structures. Firstly, the concentration inhomogeneity of Ni/Cu in PNCP is larger than that of Ni in PNP and Cu in PCP. Secondly, a Voronoi tessellation showed that the fraction of pure icosahedral arrangements around the Cu atoms increases significantly in PNCP by adding icosahedral-preferred Ni atoms in PCP. Finally, a persistent homology (PH) analysis reveals the largest intermediate-size Cu PH rings in PNCP among the PH rings in these Pd-based BMGs. The structural heterogeneity for the excellent GFA of PNCP would be considered by an incompatible mixture of specific Pd-P configurations and icosahedral clusters around the secondary Ni and Cu metals.
Pd42.5Ni7.5Cu30P20 (PNCP) metallic glass having the best GFA at present, the local structures were investigated by
combining data obtained from anomalous X-ray scattering, X-ray and neutron diffraction, and applying reverse Monte Carlo modeling. By comparing the results of PNCP with Pd40Ni40P20 (PNP) and Pd40Cu40P20 (PCP) having a slightly and much worse GFAs, respectively, characteristic features were observed in the hyper-ordered atomic structures. Firstly, the concentration inhomogeneity of Ni/Cu in PNCP is larger than that of Ni in PNP and Cu in PCP. Secondly, a Voronoi tessellation showed that the fraction of pure icosahedral arrangements around the Cu atoms increases significantly in PNCP by adding icosahedral-preferred Ni atoms in PCP. Finally, a persistent homology (PH) analysis reveals the largest intermediate-size Cu PH rings in PNCP among the PH rings in these Pd-based BMGs. The structural heterogeneity for the excellent GFA of PNCP would be considered by an incompatible mixture of specific Pd-P configurations and icosahedral clusters around the secondary Ni and Cu metals.
| Original language | English |
|---|---|
| Article number | 121868 |
| Number of pages | 12 |
| Journal | Journal of Non-Crystalline Solids X |
| Volume | 596 |
| Early online date | 25 Aug 2022 |
| DOIs | |
| Publication status | Published - 15 Nov 2022 |
Bibliographical note
Funding Information:The authors acknowledge Prof. T. Usuki and Ms. A. Höhle, and Dr. D. Szubrin for the support of AXS and ND experiments, respectively. This work was performed under the inter-university cooperative research program of the Advanced Research Center of Metallic Glasses, Institute for Materials Research, Tohoku University (Project Nos. 11G0005 and 12G0022). The AXS experiments were performed at BM02 of the ESRF (Proposal Nos. ME1002, HD162, and HD426), and the neutron scattering measurements were carried out at the ILL using the diffractometer D4 (Proposal No. 605778). SH was supported by JSPS Grant-in-Aid for Transformative Research Areas (A) ‘Hyper-Ordered Structures Science’ (Nos. 20H05878 and 21H05569), that for Scientific Research (C) (No. 22K12662), the Japan Science and Technology Agency (JST) CREST (No. JPMJCR1861), and the Deutsche Forschungsgemeinschaft (DFG) Mercator Fellowship in FOR 2824.
AZ was supported by a Royal Society–EPSRC Dorothy Hodgkin Research Fellowship, and thanks the IROAST, Kumamoto University for a visiting professorship.
Keywords
- Glass-forming ability
- Icosahedral arrangement
- Partial structure
- Persistent homology analysis
- Reverse Monte Carlo modeling
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry