Both theoretical and experimental results indicate that the Umklapp peaks

of the thermal conductivity of Fe3O4 films move toward higher temperatures with decreasing film thickness, owing to the phonon-boundary scattering. The thermal conductivity was found to be in Belnacasan molecular weight the range of 0.52 to 3.51 W/m · K at 300 K, which was 1.7 to 11.5 orders of magnitude lower than that of bulk materials at 300 K. We found that the modified Callaway theoretical model including the film thickness effect agreed well with the results obtained using the 3-ω method. Furthermore, we indirectly measured the in-plane thermal conductivity by re-analyzing the Callaway model using the measured out-of-plane thermal conductivity. We then suggested that the thin film-based oxide materials could be promising candidates as thermoelectric

materials to achieve high-performance TE devices. Acknowledgments This study was supported by the Priority selleck inhibitor Research Centers Program and by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2013R1A12012685, NRF-2013R1A4A1069528). This study was also supported by a grant from the Global Excellent Technology Innovation R&D Program funded by the Ministry of Knowledge Economy, Republic of Korea (10038702-2010-01). References 1. Majumdar A: Thermoelectricity in semiconductor nanostructures. Science 2004, 303:777–778.CrossRef 2. Hochbaum AI, Chen RK, Delgado RD, Liang WJ, Garnett EC, Najarian M, Majumdar A, Yang PD: Enhanced thermoelectric performance of rough silicon nanowires. Nature 2008, 451:163-U5.CrossRef 3. Li DY, Wu YY, Kim P, Shi L, Yang PD, Majumdar A: Thermal conductivity of individual silicon nanowires.

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