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_yFe_xCo_(4-x)Sb_(12), by a two-step solid reaction method. The maximum filling fraction of Ba (y_(max)) in Ba_yFe_xCo_(4-x)Sb_(12) was found to be rather greater than that of Ce or La in Ln_yFe_xCo_(4-x)Sb_(12). For n-type Ba_yCo_4Sb_(12), the electrical conductivity increases with increasing Ba filling fraction. The lattice thermal conductivity of Ba_yCo_4Sb_(12) is significantly depressed as compared to unfilled Co_4Sb_(12). The dimensionless thermoelectric figure of merit, ZT, increases with increasing temperature reaching a maximum value of 1.1 for Ba_(0.24)Co_4Sb_(12) at 850 K.