| 摘要 |
PROBLEM TO BE SOLVED: To provide a production process of an amorphous high-pressure phase boron nitride bulk body, which enables production of an amorphous phase corresponding to cubic boron nitride that has the greatest band gap of any substance, and also, high hardness and high thermal conductivity, both ranking next to those of diamond. SOLUTION: This production process comprises: subjecting powdery low- pressure phase boron nitride to mechanical deformation by a technique using a vibrating mill, ball mill, or the like, to obtain low-pressure phase boron nitride being in an amorphous state; treating the amorphous low-pressure phase boron nitride under a >=65,000 atm pressure at 1,200-1,500 deg.C, to realize a phase change from the amorphous low-pressure phase to an amorphous high-pressure phase of the boron nitride without causing almost any crystallization and to synthesize the objective BN amorphous high-pressure phase. An amorphous high-pressure phase boron nitride bulk body thus produced has high hardness and light- transmissive properties. |
