Elucidation of crystal morpholigic change mechanism of hexagonal boron nitride in high-temperature molten salt based on data-driven classification of contribution factors

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04807
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 28010:Nanometer-scale chemistry-related
• Research Institution: Shinshu University
• Principal Investigator: Yamada Tetsuya 信州大学, 学術研究院工学系, 助教 (80623735)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: フラックス法 / 窒化ホウ素 / データ駆動科学 / 結晶成長制御

Outline of Final Research Achievements

In this study, we classified contribution factors to low aspect ratios in the flux-based crystal growth of hexagonal boron nitride (h-BN) using data-driven analysis. As a result, we found that the cation-anion bonding distance that accords to flux-derived physical properties, plays an important role. In addition, we investigated the contribution of the adsorption energy between h-BN and flux-derived ions and found that the adsorption energy anisotropy, which depends on the adsorption orientation of the flux-derived ions, contributes to the change in the crystal aspect ratio. The contribution of flux-derived anions to h-BN can be explained as a growth mechanism involving the side capping effect on the surface h-BN during crystal growth, which suppresses crystal growth in the ab-plane direction, resulting in low-aspect ratio growth.

Free Research Field

溶液結晶成長

Academic Significance and Societal Importance of the Research Achievements

本研究が提示した，フラックスによる溶質表面吸着の仮説は，結晶成長におけるアスペクト比が何によって決まるかを理解するうえでの重要な指針として，学術的意義がある。加えて本研究の重要因子に関する知見は，h-BNのみならず様々な層状化合物の結晶成長予測モデル構築に役立ち，定量的な結晶外形制御探索に繋がる展望が拓ける．結晶外形は，材料性能と密接にかかわりがある．例えば，h-BNは高性能な熱伝導材料として知られ，低アスペクト比化することで，放熱フィラーの高伝導化・薄膜化・小型化ができる．よって，本知見が，機能性結晶材料の結晶外形を介した高性能化に資する社会的意義がある．