Thermal conductivity of (Hf _1-xZr _x) ₆Ta ₂O ₁₇ (x = 0, 0.1, 0.3 and 0.5) ceramics

(Hf _1-xZr _x) ₆Ta ₂O ₁₇ (x = 0, 0.1, 0.3 and 0.5) ceramic powders were synthesized by conventional solid-state method. The samples of these ceramics were prepared by pressureless sintering process at 1600°C for 8 h in air. X-ray diffraction characterization indicated that all samples were single phase with orthorhombic structure. The thermal diffusivities of the samples from 200°C to 1000°C were characterized by laser flash diffusivity measurement. The thermal conductivities of (Hf _1-xZr _x) ₆Ta ₂O ₁₇ decreased with the increase of zirconium content x. Thermal conductivity of (Hf _0.5Zr _0.5) ₆Ta ₂O ₁₇ was about 2.75 W/m K which was comparable with that of dense partially yttria-stabilized zirconia (∼2.5 W/m K).