Fast preparation route to high-performances textured Sr-doped Ca3Co4O9 thermoelectric materials through precursor powder modification

• Published in: Science China materials 2019-03, Vol.62 (3), p.399-406
• Main Authors: Torres, Miguel Angel, Garcia, Gustavo, Urrutibeascoa, Idoia, Madre, Maria Antonieta, Diez, Juan Carlos, Sotelo, Andres
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Chemistry/Food Science; Grain orientation; Grinding mills; High temperature; Materials Science; Mechanical properties; Porosity; Power factor; Precursors; Seebeck effect; Thermoelectric materials
• ISSN: 2095-8226; 2199-4501
• DOI: 10.1007/s40843-018-9339-1

This work presents a short and very efficient method to produce high performance textured Ca 3 Co 4 O 9 thermoelectric materials through initial powders modification. Microstructure has shown good grain orientation, and low porosity while slightly lower grain sizes were obtained in samples prepared from attrition milled powders. All samples show the high density of around 96% of the theoretical value. These similar characteristics are reflected in, approximately, the same electrical resistivity and Seebeck coefficient values for both types of samples. However, in spite of similar power factor (PF) at low temperatures, it is slightly higher at high temperature for the attrition milled samples. On the other hand, the processing time reduction (from 38 to 2 h) when using attrition milled precursors, leads to lower mechanical properties in these samples. All these data clearly point out to the similar characteristics of both kinds of samples, with a drastic processing time decrease when using attrition milled precursors, which is of the main economic importance when considering their industrial production.