Low thermal conductivity of atomic layer deposition yttria-stabilized zirconia (YSZ) thin films for thermal insulation applications

• Published in: Journal of the European Ceramic Society Vol. 37; no. 9; pp. 3131 - 3136
• Main Authors: Cho, Jungwan, Park, Joonsuk, An, Jihwan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2017
• Subjects: Atomic layer deposition; Thermal conductivity; Thermal insulation applications; Time-domain thermoreflectance; Yttria-stabilized zirconia (YSZ); Thermal conductivity; Atomic layer deposition; Yttria-stabilized zirconia (YSZ); Thermal insulation applications; Time-domain thermoreflectance
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2017.03.045

Thermal insulation applications have long required materials with low thermal conductivity, and one example is yttria (Y2O3)-stabilized zirconia (ZrO2) (YSZ) as thermal barrier coatings used in gas turbine engines. Although porosity has been a route to the low thermal conductivity of YSZ coatings, nonporous and conformal coating of YSZ thin films with low thermal conductivity may find a great impact on various thermal insulation applications in nanostructured materials and nanoscale devices. Here, we report on measurements of the thermal conductivity of atomic layer deposition-grown, nonporous YSZ thin films of thickness down to 35nm using time-domain thermoreflectance. We find that the measured thermal conductivities are 1.35–1.5Wm−1K−1 and do not strongly vary with film thickness. Without any reduction in thermal conductivity associated with porosity, the conductivities we report approach the minimum, amorphous limit, 1.25Wm−1K−1, predicted by the minimum thermal conductivity model.