The relation between the effect of silver on the amount of residual carbon and the rate of carbonate build-up on the surface of the particles of Tl1212 and Bi2212 was studied by infrared spectroscopy using a diffuse reflectance infrared-Fourier transform (DRIFT) cell. The result showed that appreciable amounts of carbonate still remained after calcination at 940 degrees C when carbonates were used as starting materials. Samples prepared using oxides also showed the presence of carbonate that originated from the CO2 adsorption at the surface during processing. The small amounts of surface carbonates were below the detection limit of X-ray diffraction. However, the DRIFT technique has been found to be a convenient and effective method for qualitative and semi-quantitative analysis of carbonate formation on the powder surface and atmospheric degradation of thallium-and bismuth-compound superconductors. The presence of silver decreased the rate of the carbonate formation on the Tl1212 and Bi2212 particle surface influencing the degradation process. Carbonate formation was more sensitive to the presence of silver in Tl1212 than in Bi2212. The presence of silver appeared to change the hydroxylation kinetics of calcium and/or strontium, which was directly related to the carbonate forming process.