著者
余語 利信 松雄 茂 中 重治
出版者
公益社団法人日本セラミックス協会
雑誌
窯業協會誌 (ISSN:18842127)
巻号頁・発行日
vol.95, no.1097, pp.94-98, 1987-01-01
被引用文献数
8

Highly pure boron nitride of low crystallinity could be synthesized from triammoniadecaborane and ammonia below 800°C under atmospheric pressure. Triammoniadecaborane reacted with ammonia at temperatures between 300° and 450°C, and formed an amorphous solid containing BN, NH and BH bonds. According to the data of IR spectrum, the BH absorption band at 2500cm<sup>-1</sup> decreased in intensity with increasing temperature, and disappeared at 800°C. The 800cm<sup>-1</sup> band assigned to the BNB bonding increased in intensity from 700° to 800°C. The degree of alignment of the B<sub>3</sub>N<sub>3</sub> hexagonal layer increased as the reaction time increased from 2h to 10h at 800°C. The X-ray diffraction profiles of the product formed at 800°C for 10h showed the broad diffractions centered at 2θ=25.5° and 42.0° (Cu Kα). The crystallization of boron nitride synthesized at 800°C for 10h proceeded above 1180°C. The 100 reflection of hexagonal boron nitride was separated from the broad 10 diffraction of the specimen heated at 1550°C for 2h. The lattice constant (c<sup>0</sup>) and size of crystallite (L<sup>c</sup>) of the specimen were 6.735 and 220Å, respectively, after heating at 1550°C under atmospheric pressure for 2h. The size of crystallite increased from 320 to 830Å as the temperature increased from 1100°C to 1500°C under 2.0GPa for 10min heating. Boron nitride synthesized by heating at 800°C for 10h crystallized to hexagonal boron nitride when heated at 1500°C and 2.0GPa for 10min.