Thermal conductivities of yttria-stabilized zirconia films measured by a laser-heating AC method

Yttria-stabilized zirconia (YSZ) films were prepared by a rf magnetron sputtering and a laser chemical vapor deposition (LCVD), and their thermal conductivities were measured using a laser-heating AC method. Sputtered-YSZ films had a dense isotropic microstructure, and the thermal conductivity was almost the same as that of a bulk YSZ. LCVD-YSZ films had an anisotropic columnar microstructure, and the thermal conductivity was 1/3–1/4 as that of a bulk YSZ. Such a low-thermal conductivity of LCVD-YSZ films would be caused by nano-gaps between columns and many nano-pores in the columns.