Letter | Published:

Transformation of Cubic Boron Nitride to a Graphitic Form of Hexagonal Boron Nitride


R. H. WENTORF1 has reported that a fragment of borazon (synthetic cubic boron nitride) was twice heated to over 2000°C. in vacuo without change. Dr. Wentorf was kind enough to supply us with some small specimens, both black and yellow. Some of these, which gave random-rotation X-ray photographs showing them to be twins (only two nearly single crystals were found), we heated in graphite specimen holders in a high-frequency vacuum furnace (10−5 cm. mercury) in a series of experiments to compare their behaviour with that of diamonds of various kinds. Table 1 shows the effects given by subsequent X-ray powder photographs.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Wentorf, jun., R. H., J. Chem. Phys., 26, 956 (1957).

  2. 2

    Pease, R. S., Acta Cryst., 5, 356 (1952).

  3. 3

    Grenville-Wells, H. J., Mineralog. Mag., 29, 803 (1952).

Download references

Author information

Rights and permissions

Reprints and Permissions

About this article

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.