Thin layers prepared by pulsed laser deposition from Yb0.19Co4Sb12 target

Bulk Yb_0.19Co₄Sb₁₂ skutterudite prepared by hot pressing was found to be a good high temperature thermoelectric material with a high figure of merit ZT (ZT=1.2 at T=650 K). In this contribution the properties of thin layers prepared by pulsed laser deposition from such target are presented. The target was prepared by hot pressing and was proved to be a skutterudite structure. The thin films were deposited on quartz glass substrates using KrF excimer laser. The substrate temperature during the deposition was 200 degC, 250 degC, 300 degC or 410 degC, the energy density of the laser beam was held at 2 J/cm², 3 J/cm² or 5 J/cm ² for individual experiments. The deposition took place in Ar atmosphere of 13 Pa. The layers from 150 nm up to 440 nm were examined by X-ray diffraction method. Depending on the deposition conditions the layers between amorphous and skutterudite structures were obtained. For some samples, CoSb₂ phase and mixed CoSb₂ phase with skutterudite structure were also observed. For the layer with skutterudite structure the homogeneity and relative quantity of Yb across the 1cm² of the surface was examined by secondary ion mass spectrometry. The 60 nm thick layers with skutterudite structure were characterized by Seebeck coefficient and resistivity measurements in the temperature range from 300 K to 550 K. The results are compared with the published results for the bulk material