| Popis: |
A temperature gradient method was applied to grow a large cubic boron nitride (cBN) crystal under 5.5 to 6 GPa and 1700 to 1950°C using Li 3 BN 2 as a solvent. The crystals, free from inclusions and cracks, were grown successfully on a seed crystal without spontaneous nucleation. The grown crystals consists of large { 1 1 l }, mostly { 1 1 3 }, faces, a nd small {111}, { 1 1 1 } and {100} faces, in contrast to the latter three faces being predominant in commercial cBN, Borazon. The { 1 1 l } and {100} faces are characterized by striations parallel to 〈110〉 and estimated to correspond to the nitrogen-terminating surfaces. Most crystals contain many { 1 1 1 } twin lamellae, resulting in complicated habit. |
