Titanium carbonitrides (TiCxN1-x ) are known by their excellent properties. They are widely used in cutting tools and in the preparation of advanced engineering ceramic-based composites. It has been found that TiC0.3N0.7 is a precursor of carbon nitride (C3N4) which has a structure similar to that of Si3N4 and a hardness comparable to diamond. Due to the exciting potential of C3N4, a large effort has been put into synthesizing it. However to date, the synthesis of C3N4 as a crystalline material has not been achieved. This thesis work aims to crystallize C3N4 on SiC and Si3N4 substrates. Four different mixtures were studied in this project: TiC0.3N0.7/Si3N4 and TiC0.7N0.3/SiC with different molar ratios (2:1) and (1:1). Differential scanning calorimetry (DSC) and Thermogravimetry (TG) were first used in both nitrogen and argon gas in order to study the thermal behaviour of the mixtures and X-ray diffraction (XRD) was used afterwards to determine the composition of the new phases. DSC/TG results show that in argon atmosphere, the mixtures TiC0.3N0.7: Si3N4 (2:1) and TiC0.7N0.3: SiC (2:1) decompose at 1300 °C. While they decompose at 1450 °C in nitrogen atmosphere.XRD results indicate that at 1450 °C, TiC0.3N0.7: Si3N4 with molar ratios (2:1) and (1:1) decompose to SiC and TiN. Besides that, TiC0.7N0.3: SiC with molar ratio (2:1) decomposes to Si3N4 and Ti2N. The thermal analysis results show that TiC0.3N0.7/Si3N4 and TiC0.7N0.3/SiC might be interesting precursors for C3N4.