Rapid nucleation and crystallization induced by microsegregation of glasses

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15663
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 36010:Inorganic compounds and inorganic materials chemistry-related
• Research Institution: National Institute of Advanced Industrial Science and Technology
• Principal Investigator: Shinozaki Kenji 国立研究開発法人産業技術総合研究所, 材料・化学領域, 主任研究員 (10723489)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 核形成 / 不均質 / ナノ結晶 / 中距離構造 / X線全散乱 / 分子動力学法 / 第一原理計算 / アップコンバージョン

Outline of Final Research Achievements

We proposed a new material design guideline for inducing microsegregation and enabled ultrafast nucleation via microsegregation as a nucleation site in this study. In order to investigate the structure of microsegregation, we analyzed the radial distribution function and performed molecular dynamics simulations. It was proposed that the mixing state of glass can be controlled by adding a third component of intermediate polarity to the fluorides such as BaF2 and oxides such as B2O3, which have low miscibility as suggested by the HBSA rule. This provides a guideline for designing a structure suitable for nucleation. Furthermore, we worked on the crystallization of glass during the cooling process of the melt, and demonstrated that nanocrystallization is possible during the cooling process.

Free Research Field

無機材料科学

Academic Significance and Societal Importance of the Research Achievements

ガラス（または過冷却融液）から析出する結晶の粒径は、核形成と結晶成長のそれぞれの速度の競合によって決まり、核形成が速く成長が遅ければ結晶粒径は小さくなる。結晶成長の制御は粘性の調整等の指針がある一方、核形成については十分理解が進んでおらず、これまでは試行錯誤により制御するしかなかった。本研究ではガラスと結晶の構造類似性の設計方法を提案し、ガラス構造設計により核形成を加速する指針を明らかにした。また、従来困難だった急冷過程でのナノ結晶化にも成功した。この成果はより高効率の材料開発及び、高生産性での材料作製やデバイス形成の実現につながる。