Transition layers between CVD diamond films and substrates of strong carbide forming elements : vanadium, chromium, zirconium and hafnium

Among the strong carbide forming elements, ten of them have the melting points above 1400 degrees Centigrade. The observed transition layers between CVD diamond films and the substrates of Mo, Si, W, Ta, Nb and Ti had been reported at the Diamond Optics IV ⁽¹⁾• In this paper, the further research results on iransition layers for the substrate elements of V, Cr, Zr and Hf are presented. The specimens are prepared in an arc discharge plasma CVD system with the substrate temperature of 900-1000 degrees Centigrade and characterized by a high resolution X-ray diffraction instrument. The experimental results show that the transition layers are polycrystalline VC and V₂C, Cr₇C₃ and Hfc for the substrates of V, Cr and Hf respectively. For the transition layers between CVD diamond films and Zr substrates, the composition of polycrystalline ZrH, ZrC and their complex compound are verified and the content of hydride is comparable to the content of carbide in this case.