Resumen: Bi2Ca2Co1.7Ox thermoelectric ceramics with small Ag additions (0, 1, 2, 3, 4, and 5 wt.%) have been successfully grown from the melt, using the laser floating zone method and subsequently annealed at 800 °C for 24 h. The microstructure has shown a reduction of the amount of secondary phases for Ag contents up to 4 wt.%. This microstructural evolution leads to a decrease of the electrical resistivity values until an Ag content of 4 wt.%, whereas Seebeck coefficient has been maintained unchanged. This is in agreement with the presence of metallic Ag in all samples, confirmed not only by Energy Dispersive Spectrometry but also by X-ray photoelectron and Auger spectroscopy. These electrical properties lead to maximum power factor values of about 0.30 mW/K2.m at 650 °C for the 4 wt.% Ag containing samples, which is among the best results obtained for this type of materials. Idioma: Inglés DOI: 10.1016/j.actamat.2015.09.036 Año: 2016 Publicado en: Acta Materialia 102 (2016), 273-283 ISSN: 1359-6454 Factor impacto JCR: 5.301 (2016) Categ. JCR: METALLURGY & METALLURGICAL ENGINEERING rank: 1 / 74 = 0.014 (2016) - Q1 - T1 Categ. JCR: MATERIALS SCIENCE, MULTIDISCIPLINARY rank: 35 / 273 = 0.128 (2016) - Q1 - T1 Factor impacto SCIMAGO: 3.21 - Electronic, Optical and Magnetic Materials (Q1) - Polymers and Plastics (Q1) - Metals and Alloys (Q1) - Ceramics and Composites (Q1)