Thermoelectric properties of n-type Ba_yNi_xCo_4-xSb1₂

Effects of Ba filling fraction and Ni content on the thermoelectric properties of n-type Ba_y Ni_x Co_4-xSb₁₂(x = 0 - 0.1, y = 0 - 0.4) were investigated. Thermal conductivity decreased with increasing Ba filling fraction and temperature. When y was fixed at 0.3, the thermal conductivity decreased with increasing Ni content, and reached a minimum value at about x = 0.05. Lattice thermal conductivity decreased with increasing Ni content, monotonically (y ≤ 0.1). Electron concentration and electrical conductivity increased with increasing Ba filling fraction and Ni content. Seebeck coefficient decreased with increasing Ba filling fraction and Ni content. The maximum ZT value of 1.2 was obtained at about 900 K for n-type Ba_0.3Ni_0.05Co_3.95Sb₁₂.