Rapid fabrication and low-temperature transport properties of nanostructured p-type CexCo4Sb12.04 (x=0.15, 0.20 and 0.30) using solvothermal synthesis and evacuated-and-encapsulated heating

Polycrystalline p-type CexCo4Sb12.04 with x=0.15, 0.20 and 0.30 are fabricated using a combination of solvothermal synthesis at 260 °C for 24 h and evacuated-and-encapsulated heating at 600 °C for 5 h. The X-ray diffraction patterns reveal that all the compositions are of single phase. The thermopower of all the samples is positive, indicating that the predominant carriers are holes over the investigated temperature range of 80–300 K. The electrical resistivity and thermopower simultaneously decrease with increasing Ce filling content. Analyses of the temperature dependence of both electrical resistivity and thermopower indicate that all the samples obey the variable range hopping transport mechanism. Among the samples, Ce0.20Co4Sb12.04 exhibits the highest power factor of 0.29 μW cm−1 K−2 at 300 K. This value represents an improvement of about 556% compared to pristine Co4Sb12.04.