Barium-filled skutterudite: a high performance n-type thermoelectric material

摘要

Filled skutterudites are receiving great attention as a prospective thermoelectric material due to their large carrier mobility and glasslike thermal properties. In the present work, we synthesized a new type filled skutterudite using Ba as filling atom, Ba{sub}yFe{sub}xCo{sub}(4-x)Sb{sub}12, by a two-step solid reaction method. The maximum filling fraction of Ba (y{sub}(max)) in Ba{sub}yFe{sub}xCo{sub}(4-x)Sb{sub}12 was found to be rather greater than that of Ce or La in Ln{sub}yFe{sub}xCo{sub}(4-x)Sb{sub}12. For n-type Ba{sub}yCo{sub}4Sb{sub}12, the electrical conductivity increases with increasing Ba filling fraction. The lattice thermal conductivity of Ba{sub}yCo{sub}4Sb{sub}12 is significantly depressed as compared to unfilled Co{sub}4Sb{sub}12. The dimensionless thermoelectric figure of merit, ZT, increases with increasing temperature reaching a maximum value of 1.1 for Ba{sub}0.24Co{sub}4Sb{sub}12 at 850 K.