Berlin 2005 – wissenschaftliches Programm

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DS: Dünne Schichten

DS 14: Schichtherstellung mit Laserverfahren

DS 14.4: Vortrag

Montag, 7. März 2005, 16:00–16:15, TU HS107

Pulsed laser deposition of thin Na_xCoO₂ films — •Yoshiharu Krockenberger¹, I. Fritsch¹, A. Matveev¹, G. Cristiani¹, H.-U. Habermeier¹, L. Alff², and B. Keimer¹ — ¹Max Planck Institute for Solid State Research, Stuttgart, Germany — ²Technical University of Vienna, Austria

At present layered cobaltates attract much interest as superconductivity was found in hydrated and deintercalated samples. Due to electronic and structural analogies between Na_xCoO₂ ·1.3H₂O and high T_c copper oxides, it is even discussed that superconductivity may have a similar underlying origin in both materials. Terasaki et al. reported large thermoelectric power values for Na_xCoO₂ with simultaneously low resistivity suggesting a promising material for thermoelectrical applications. Here, we report on the growth of thin Na_xCoO₂ films. Based on a log(p_O2)−1/T phase diagram single phase Na_xCoO₂ thin films have been grown from a Na₁CoO₂ target by pulsed laser deposition technique. In a high vacuum chamber optimization of kinetics and oxidation power was performed for oxygen and nitrous oxide. Additionally, different types of substrates were used in order to study the growth conditions of Na_xCoO₂. The samples have been characterized by x-ray diffraction and Raman spectroscopy. Resistivity measurements show good metallic behaviour.