Effect of Ag additions on the Bi1.6Pb0.4Sr2Co1.8Ox thermoelectric properties

Bi1.6Pb0.4Sr2Co1.8Ox thermoelectric ceramics with small Ag additions (0, 1, and 3 wt.%) have been successfully produced by a sol-gel method via nitrates. Microstructure has shown a reduction on the amount of secondary phases and an increase on the bulk density with increasing Ag contents. The microstructural evolution, as a function of Ag content, is confirmed with the electrical resistivity values which show an important decrease for the 3 wt.% Ag samples, leading to maximum power factor values of about 0.025 mW/K2.m at room temperature, which is about two times higher than the obtained for the Ag-free sintered samples. (Author)