Luckyanova M N, Chen D, Ma W, et al. Thermal conductivity control by oxygen defect concentration modification in reducible oxides: The case of Pr0. 1Ce0. 9O2− δ thin films[J]. Applied Physics Letters, 2014, 104(6): 061911.

ABSTRACT

We demonstrate the impact on thermal conductivity of varying the concentration of oxygenvacancies and reduced cations in Pr0.1Ce0.9O2dthin films prepared by pulsed laser deposition. Theoxygen vacancy concentration is controlled by varying the oxygen partial pressure between1104and 1 atm at 650C. Corresponding changes in the oxygen non-stoichiometry (d) aremonitored by detecting the lattice parameters of the films with high-resolution X-ray diffraction,while the thermal properties are characterized by time-domain thermoreflectance measurements.The films are shown to exhibit a variation in oxygen vacancy content, and in the Pr3þ/Pr4þratio,corresponding to changes indfrom 0.0027 to 0.0364, leading to a reduction in the thermalconductivity fromk¼6.6260.61 to 3.8260.51 W/m-K, respectively. These values agree wellwith those predicted by the Callaway and von Baeyer model for thermal conductivity in thepresence of point imperfections. These results demonstrate the capability of controlling thermalconductivity via control of anion and cation defect concentrations in a given reducible oxid