The efficiency of thermoelectric (TE) materials through the figure of merit zT is linked to the thermal conductivity of the material. Although, evaluate the thermal conductivity of TE materials can be very challenging due to the micro/nanoscale interaction between the probe and the sample. Some of the current thermal methods have spatial resolution issues, which make the evaluation more difficult in the case of nanostructures materials [1]. However, the 3w-SThM (Scanning Thermal Microscopy) is a powerful technique for thermal measurements and using a commercial silicon nitride probe with palladium film is possible to achieve more than 100 nm of spatial resolution. In this work, the thermal conductivity measurements with this spatial resolution is very important to analyses anodic TiO2 nanotubes layers (TNTL), since the Magnéli phase titanium oxides exhibits interesting properties for TE applications [2]. The thermal behaviour of TNTL is determined with the SThM technique that can measure simultaneously, topographic and thermal images of the samples; electrical and morphological characterization of TiO2 nanotubes is also discussed.

Trabajo presentado en la 14th European Conference on Thermoelectrics (ECT2016), celebrada en Lisboa (Portugal), del 20 al 23 de septiembre de 2016

Peer reviewed