Method for growing boron nitride crystals of cubic system

摘要

Cubic boron nitride crystals are grown by subjecting reaction materials of low pressure phase boron nitride, a solvent material, and cubic boron nitride seeds to pressure and temperature conditions in the cubic boron nitride-stable region. The reaction materials are in the form of a pair of a superimposed solvent material plate and a low pressure phase boron nitride plate or a pile made of a plurality of the pairs of the superimposed solvent material plate and low pressure phase boron nitride plate, and a plurality of the seeds are disposed on either one or each of the confronting surfaces of the pair of the superimposed solvent material plate and low pressure phase boron nitride plate. Alternatively, the reaction materials are in the form of a plate made of a mixture of the solvent material and the low pressure phase boron nitride or a pile made of a plurality of the mixture plates, and a plurality of the seeds are disposed on a surface of each plate. The seeds have a particle size of not larger than 150 mu m and are regularly disposed in such a manner that the seeds are located at a substantially equal distance and the distance between the peripheries of every two adjacent grown cubic boron nitride crystal particles is from 20 to 200 mu m. The cubic boron nitride crystals are allowed to grow until their sizes reach at least 1.5 times the size of the seeds.