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Abstract: Cubic boron nitride (c-BN) crystals were synthesized in conditions of high temperature and high pressure (HTHP) when different kinds of bonded water were respectively added into the system of h-BN–Mg. All bonded water used in this work could reduce the temperature of growing c-BN compared to that in the system of h-BN–Mg. The c-BN color could change from black to yellow when certain amounts of bonded water, such as NiSO4·6H2O and CuSO4·5H2O, Mg(OH)2, were added. However, c-BN color remained black no matter how much bonded water, such as NiCl2·6H2O, CuCl2·2H2O, and SnCl2·2H2O, was added. The bonded water can be classified into Chlorine-containing bonded water (Cl-BW) and Chlorine-free bonded water (ClF-BW) according to their different characters and effects on the synthesized c-BN color. [Copyright &y& Elsevier]

Low-threshold heterojunctions have been formed from a boron-doped p-type diamond layer grown epitaxially on the {1 1 1} surface of a Si-treated single crystalline cubic boron nitride. The resistivity of the Si-treated cubic boron nitride was 0.1 Ω cm. With the resistivity of 0.1 Ω cm, which is lower than that of the sample prepared by conventional high-temperature and high-pressure method, the turn-on voltage and the highest current of the heterojunction are 0.5 V and 1 mA, respectively. [Copyright &y& Elsevier]