Abstract
In the present study, we synthesized Nb- or Ta-doped BaSnO3 ceramics and characterized the thermal conductivities. The doped samples BaSn1-xMxO3-δ (M = Nb or Ta, x = 0, 0.05, 0.10, 0.15, 0.20) were synthesized by solid state reactions followed by spark plasma sintering (SPS). The lattice parameters of BaSn1-xNbxO3-δ and BaSn1-xTaxO3-δ increased almost linearly with increasing the doping level, then remained constant at x = 0.10 and x = 0.15, respectively. After the solubility limit, peaks for Ba2SnO4 were observed in the powder XRD patterns of both the Nb- and Ta-doped samples. The thermal conductivity of BaSn0.95Nb0.05O3-δ was clearly lower than that of BaSn0.95Ta0.05O3-δ , mainly caused by its small speed of sounds and a short mean free pass of phonons compared with those of BaSn0.95Ta0.05O3-δ.
