镁热还原法制备圆片状氮化硼多晶微粉

采用三氧化二硼(B₂O₃)、氯化铵(NH₄Cl)和镁粉为反应物, 以三氧化二铁(Fe₂O₃)为催化剂, 利用镁热还原法在700～850 ℃下反应, 制备了氮化硼多晶微粉. X射线衍射(XRD)分析表明, 产物为六方相, 晶格常数a=0.2499 nm, c=0.6682 nm. 产物的红外光谱中在790和1380 cm^-1处出现了六方氮化硼的特征吸收峰. 利用扫描电子显微镜(SEM)观察到产物为圆片状颗粒, 平均直径约为0.9 μm, 平均厚度约为100 nm. 讨论了Fe2O3的存在对产物形成的影响.

Magnesiothermic Reduction Preparation of Polycrystalline Hexagonal Boron Nitride with Round-flake Morphology

Polycrystalline boron nitride(BN) powders were prepared by magnesiothermic reduction of boron oxide(B2O3) and ammonium chloride(NH4Cl) catalyzed with ferric oxide(Fe2O3) at temperatures ranging from 700 to 850 ℃ under ambient pressure. X-ray diffraction(XRD) result shows a hexagonal phase with lattice parameters a=0.2499 nm and c=0.6682 nm. Fourier transform infrared(FTIR) spectroscopy indicates characteristic absorption peaks of hexagonal BN at 790 and 1380 cm-1. Scanning electron microscopy(SEM) reveals that the submicro-polycrystallites have approximately uniform round-flake morphology with an average diameter of about 0.9 μm and an average thickness of about 100 nm. Catalytic formation mechanism of the product was also discussed.