The Medium Range Ordering of Amorphous Alloys: Chemical Short Range Ordring and Bernal Polyhedra

• Project/Area Number: 16H04210
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Inorganic industrial materials
• Research Institution: Tohoku University
• Principal Investigator: Sugiyama Kazumasa 東北大学, 金属材料研究所, 教授 (40196762)
• Co-Investigator(Kenkyū-buntansha): 有馬 寛 一般財団法人総合科学研究機構(総合科学研究センター(総合科学研究室)及び中性子科学センター(研究開発, 中性子科学センター, 研究員 (60535665)
• Research Collaborator: KAWAMATA TORU
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥15,860,000 (Direct Cost: ¥12,200,000、Indirect Cost: ¥3,660,000); Fiscal Year 2018: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2017: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000); Fiscal Year 2016: ¥10,010,000 (Direct Cost: ¥7,700,000、Indirect Cost: ¥2,310,000)
• Keywords: amorphous metal / short range ordering / middle range ordering / anomalous scattering / reverse Monte Calro / radial distribution / amorphous alloy / pre-peak / medium range ordering / X-ray scattering / RDF / 非晶質 / 中距離構造 / バーナル多面体 / 異常散乱 / リバースモンテカルロ / reverse Monte Carlo / 非晶質金属 / Ｘ線異常散乱 / Ｘ線 / 解析・評価 / 放射光

Outline of Final Research Achievements

In this study, we used the advanced AXS-RMC method to evaluate the medium-range ordering structure of an amorphous alloy that shows a pre-peak signal in the diffraction profile. It was clarified that the clear short-range ordering structures such as icosahedral cluster (TSRO) and/or the strongly binding solute-center model (CSRO), which have been regarded as the origin of pre-peaks in the past, are not essential elements for the appearance of pre-peak signals. And, according to the newly developed CA-Bernal analysis, the identity of pre-peak signal is suggested to be formed by the harmony of the strongly binding Bernal-typed high density domain structure (CMRO) and the non-Bernal-typed low density domain structure (TMRO) inherent in composition and density non-uniformity.

Academic Significance and Societal Importance of the Research Achievements

非晶質合金中の中距離領域構造はガラス形成能や機械的特性などの巨視的な材料特性に影響をおよぼす重要な要素であると議論されているが，その詳細は金属分野における未解決問題の１つとなっていた．本研究は，回折プロファイルにプレピークをもつ非晶質合金を研究対象に，研究グループ独自のAXS-RMC法とCN-Bernal解析を駆使して，中距離領域構造の詳細を解明した．溶質元素と溶媒元素の強い結合性に起因する充填密度の大きなBernal型CMROと溶媒元素の希薄な充填密度の低い非Bernal型TMROの協奏は，ランダム系物質の構造を理解するための学術的なブレイクスルーとなると確信している．

Research Products

• [Journal Article] Nanometer-Sized Crystalline Clusters of IGZO Films Determined from the Grazing Incidence X-ray Scattering and Anomalous X-ray Scattering Data Combined with Reverse Monte Carlo Simulations (2018)
  • Author(s): Waseda Yoshio, Sugiyama Kazumasa, Kawamata Toru
  • Journal Title: MATERIALS TRANSACTIONS Volume: 59 Issue: 11 Pages: 1691-1700
  • DOI: 10.2320/matertrans.M2018231
  • NAID: 40021711614
  • ISSN: 1345-9678, 1347-5320
  • Year and Date: 2018-11-01
  • Peer Reviewed
• [Journal Article] Medium Range Ordering realized in Zr80Pt20Amorphous Alloy (2017)
  • Author(s): K Sugiyama, T Kawamata and T Muto
  • Journal Title: IOP Conf. Series: Journal of Physics: Conf. Series Volume: 809 Pages: 012005-012005
  • DOI: 10.1088/1742-6596/809/1/012005
  • Peer Reviewed
• [Presentation] X線異常散乱法を用いた非晶質合金の中距離秩序構造解析 (2018)
  • Author(s): 川又透, 杉山和正
  • Organizer: 日本化学会
  • Invited
• [Presentation] Ni-Nb 系非晶質合金の局所構造単位 (2017)
  • Author(s): 黒田 燎， 有馬 寛， 杉山 和正， 川又 透
  • Organizer: 日本金属学会
• [Presentation] X線異常散乱法を用いたNi-Nb系非晶質合金の構造解析 (2017)
  • Author(s): 黒田燎，有馬寛，杉山和正，川又透
  • Organizer: 2016年度量子ビームサイエンスフェスタ
• [Presentation] Ni-Nb 系非晶質合金の局所構造単位 (2017)
  • Author(s): 黒田 燎，有馬 寛，川又 透，杉山 和正
  • Organizer: 日本金属学会 2017 年秋期講演大会(第161 回)
• [Presentation] 原子レベルの構造解析；放射光異常散乱法の利用 (2017)
  • Author(s): 杉山和正
  • Organizer: 日本金属学会東北支部
  • Invited
• [Presentation] AXS-RMC法を用いたZr-Co系非晶質合金の構造解析 (2017)
  • Author(s): 黒田 燎，有馬 寛，川又 透，杉山 和正
  • Organizer: 日本金属学会東北支部