Solid-state Reaction Studies in AI(2)O(3)-TiO2 System by Diffusion Couple Method

In order to study the formation mechanism of AI(2)TiO(5) , the solid-state inter-reaction between AI(2)O(3) and TiO2 under Ar atmosphere was investigated in the temperatures range from 1 723 to 1 873 K by the diffusion couple method. The phase of the inter-compound and the change of the concentration of Ti across the diffusion layers were confirmed by the electron probe microanalysis (EPMA). Based on the concentration profile of Ti element, the thickness of diffusion layers was obtained and the interdiffusion coefficients which were affected by temperature and concentration of Ti were calculated by the Wagner method. The experimental results indicate that the thickness of diffusion layers increases with the diffusion time. The magnitudes of interdiffusion coefficients were in the range of 10(-10)similar to 10(-12) cm(2)s and the range of diffusion activity energy E-D was from 266.77 kJ/mol to 309.96 kJ/mol.