Editing Boron nitride (section)

===Preparation of cubic BN===
c-BN is prepared analogously to the preparation of [[synthetic diamond]] from graphite. Direct conversion of hexagonal boron nitride to the cubic form has been observed at pressures between 5 and 18&nbsp;GPa and temperatures between 1730 and 3230&nbsp;°C, that is similar parameters as for direct graphite-diamond conversion.<ref name=wentorf>{{cite journal | author = Wentorf, R. H. Jr. | author-link = Robert H. Wentorf, Jr. |date=March 1961 | title = Synthesis of the Cubic Form of Boron Nitride | journal = Journal of Chemical Physics | volume = 34 | issue = 3 | pages = 809–812 | doi = 10.1063/1.1731679 |bibcode = 1961JChPh..34..809W}}</ref> The addition of a small amount of boron oxide can lower the required pressure to 4–7&nbsp;GPa and temperature to 1500&nbsp;°C. As in diamond synthesis, to further reduce the conversion pressures and temperatures, a catalyst is added, such as lithium, potassium, or magnesium, their nitrides, their fluoronitrides, water with ammonium compounds, or hydrazine.<ref name=vel>{{cite journal | doi = 10.1016/0921-5107(91)90121-B | title = Cubic Boron Nitride: Synthesis, Physicochemical Properties and Applications | author = Vel, L. | journal = Materials Science and Engineering: B | volume = 10 | year = 1991 | page = 149 | issue = 2 |display-authors=etal}}</ref><ref>{{cite journal | author = Fukunaga, O. | title = Science and Technology in the Recent Development of Boron Nitride Materials | year = 2002 | journal = Journal of Physics: Condensed Matter | volume = 14 | page = 10979 | doi = 10.1088/0953-8984/14/44/413 | issue = 44 |bibcode = 2002JPCM...1410979F | s2cid = 250835481}}</ref> Other industrial synthesis methods, again borrowed from diamond growth, use crystal growth in a temperature gradient, or explosive [[shock wave]]. The shock wave method is used to produce material called [[heterodiamond]], a superhard compound of boron, carbon, and nitrogen.<ref>{{cite journal | author = Komatsu, T. | title = Creation of Superhard B–C–N Heterodiamond Using an Advanced Shock Wave Compression Technology | journal = Journal of Materials Processing Technology | volume = 85 | issue = 1–3 | year = 1999 | page = 69 | doi = 10.1016/S0924-0136(98)00263-5 |display-authors=etal}}</ref>

Low-pressure deposition of thin films of cubic boron nitride is possible. As in diamond growth, the major problem is to suppress the growth of hexagonal phases (h-BN or graphite, respectively). Whereas in diamond growth this is achieved by adding hydrogen gas, [[boron trifluoride]] is used for c-BN. [[Ion beam deposition]], [[plasma-enhanced chemical vapor deposition]], [[pulsed laser deposition]], [[Sputter deposition|reactive sputtering]], and other [[physical vapor deposition]] methods are used as well.<ref name=cvd>{{cite journal | title = Review of Advances in Cubic Boron Nitride Film Synthesis | author = Mirkarimi, P. B. | volume = 21 | year = 1997 | pages = 47–100 | doi = 10.1016/S0927-796X(97)00009-0 | journal = Materials Science and Engineering: R: Reports | issue = 2 |display-authors=etal| url = https://zenodo.org/record/1260151}}</ref>