2026-06-17 東北大学
図1. 針状AlN種結晶上に溶液成長法でエピタキシャル成長させた後のSEM像
（成長温度：1948～1923 K、冷却速度：(a) 0.05、(b) 0.1、(c) 0.2 K/min）
＜関連情報＞
- https://www.tohoku.ac.jp/japanese/2026/06/press20260617-01-aluminum.html
- https://www.sciencedirect.com/science/article/pii/S0264127526009433
アルミニウムの直接窒化によるAlN核生成および結晶成長の準平衡熱力学的制御 Near-equilibrium thermodynamic control of AlN nucleation and crystal growth via direct nitridation of aluminum
Sen Li, Chiaki Amei, Masayoshi Adachi, Makoto Ohtsuka, Hiroyuki Fukuyama
Materials & Design Available online: 8 June 2026
DOI:https://doi.org/10.1016/j.matdes.2026.116370
Highlights
- Direct nitridation of aluminum enabled controlled nucleation and growth of aluminum nitride crystals.
- A near-equilibrium strategy was developed to suppress excessive nucleation during crystal growth.
- Thermodynamic calculations guided the design of key parameters for near-equilibrium growth.
- Centimeter-long needle-like aluminum nitride single crystals with diameters up to 300 μm were obtained.
Abstract
In this study, a near-equilibrium thermodynamic strategy for the direct nitridation of aluminum was developed to control AlN nucleation and crystal growth by deliberately reducing the driving force. Guided by thermodynamic calculations, the Fe-Al alloy composition, nitrogen partial pressure, and reaction temperature were designed to maintain the system close to the thermodynamic equilibrium. Under these conditions, the reduced driving force effectively suppressed excessive nucleation, enabling the growth of needle-like AlN single crystals with lengths of several centimeters and diameters of up to 300 μm, rather than polycrystalline aggregates. These crystals were subsequently used as seeds for near-equilibrium solution growth in a Fe-Cr flux, allowing rapid crystal enlargement at rates of up to 175 μm/h, while maintaining excellent crystallinity.
