Phase-selective synthesis of cubic boron nitride in hydrothermal solutions
Abstract
A novel "in situ phase-selective route" has been developed, and it was used for the synthesis of cubic boron nitride (cBN) under hydrothermal conditions. The results showed that, if H 3BO 3, NaN 3 and N 2H 4·H 2O were mixed at room temperature and ambient pressure, explosion boron nitride (eBN) was the dominant phase in the sample prepared at 300°C and 10 MPa. In contrast, if the reactants were separated with each other at room temperature and ambient pressure, and slowly mixed at high temperature and high pressure (namely, 300°C and 10 MPa) conditions, cBN crystals as large as 0.5 mm could be synthesized. This method was called "in situ phase-selective route", it should also be an effective method for the synthesis of diamond crystals in solvothermal and hydrothermal solutions.
- Publication:
-
Journal of Crystal Growth
- Pub Date:
- September 2004
- DOI:
- 10.1016/j.jcrysgro.2004.05.066
- Bibcode:
- 2004JCrGr.269..570Y