Nitride Synthesis Method Of Exploration And Nature Study

Because of many merits, such as high-temperature resistance, corrosive-resistance, high thermal conductivity, high electrical resistivity and excellent lubricating properties, hexagonal boron nitride (hBN) is an important material, which has been widely used in petroleum, chemical engineering, machine fabrication, electronics.electrical power, nuclear industry, avigation etc. On the other hand, as the second hardest material known, cubic boron also possesses many merits, for example, high stability, high thermal conductivity, high hardness and wide band gap etc. Although the hardness of cBN is inferior to that of diamond, its stability is higher than the latter. Besides, unlike diamond, cBN dose not react with ferrous metals, which make it the unrivaled material for fabricating cutting tools, super-hard protective coatings and grinding materials etc. Because of the above advantages, cBN can also be used in the fabrication of high-power semiconductor devices, short wavelength optoelectronic devices, ultraviolet detectors, high power microwave devices, heat sinks and high transparency windows etc.As the typical representative of the third generation semiconductors, gallium nitride is an excellent wide band gap semiconductor, and it is an ideal candidate for fabricating green and blue light-emitting diodes (LEDs) and laser diodes (LDs). These optoelectronic devices can be widely used in high density information storage, high-speed laser print, full color display, solid state illumination, high speed light communication etc. If the optoelectronic devices can be grown on GaN bulk crystal, their performance will improved very much, so GaN bulk crystal is the ideal substrate for fabrication this kind of optoelectronic devices. So, it is very important to develop new and effective methods for growing GaN bulk crystals.On the basis of the above consideration, we have carried out a series of explorations on the new synthesis methods for preparation of both cBN nanoparticles and GaN bulk crystals. The main results are as follows:For the first time, we established the solvothermal phase-selective reaction method.