Solid state reaction of titanium and (0001) α-SiC

Abstract

The kinetics and products of the solid state reaction of titanium thin films and (0001) α-SiC were investigated in the temperature range 844–1073 K using X-ray diffractometry and Auger electron spectroscopy. Reaction couples were prepared by the electron beam evaporation of titanium films 350 nm thick onto polished and argon-sputtered Lely-grown SiC platelets. The couples were isothermally annealed at temperatures between 844 and 1073 K at pressures of not greater than 4 x10 -7 Pa. The interfacial reaction released carbon and silicon which interdiffused with the titanium layer and formed TiC; titanium silicides were not observed as reaction products. The quantity x of silicon released in the interfacial reaction was fitted to the parabolic growth law dx dt = k x , and the temperature dependence of the rate constant was determined as k = 0.065 cm 2 s -1 exp( -262.7 kJ mol -1 RT ) . This rate constant is consistent with data previously reported at temperatures between 923 and 1255 K, and it enables accurate predictions of the extent of interfacial reactions in thin film Ti-single-crystal SiC couples to be calculated for temperatures as low as 840 K and for reaction layers less than 0.5 μm thick.