WU Gai, CHEN Mei-hua, LIU Jian-hong, LIAO Jia, GONG Ni-na
(China University of Geosciences, Wuhan 430074, China)
Abstract: Eleven grains of HPHT synthetic diamond were used to grow CVD diamond layers under different CH4/H2 ratios, temperatures and pressures. Samples were analyzed by infrared spectroscopy (FTIR) quantitatively as well as with Raman spectrometry. The morphology of samples was also observed with Raman spectroscopy. Test results showed the crystalline quality of CVD synthetic diamond is as good as that of the HPHT synthetic diamond but with the existence of some internal stress from synthesis. The high CH4/H2 ratio has no significant effect on promoting diamond growth, but may increase C-H defects and inhibit the rapid growth rate. Furthermore, temperature plays an important role in CVD diamond growth rate. Moderate temperature increases can promote the formation of growth steps and noticeably improve the rate of growth.
Key words: CVD synthetic diamond; infrared spectrum; Raman spectrum; CH4/H2 ratio; temperature
ACTA MINERALOGICA SINICA Vol. 34, No. 3, 2014, Page 411-415
