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MM: Metall- und Materialphysik

MM 25: Poster Session

MM 25.38: Poster

Mittwoch, 29. März 2006, 15:30–17:30, P4

Effective Electron Mass of SrTiO3 based Thermoelectric Nano-Materials — •Wilfried Wunderlich — Nagoya Institute of Technology and Nagoya University, JST-CREST, Japan

The effective mass of electrons was calculated from the curvature of the electronic bands by ab-initio using Vasp- and Wien2k-code, which are based of the density-functional theory. The effective mass measured by the Hall effect in Nb-doped SrTiO3 single crystals showed comparable, but slightly larger values, which can be explained by interaction effects with phonons, polarons or other electrons. The understanding of these phenomena can be utilized in the improvement of thermoelectric materials based on layered composite materials, where the electrons travel nearly ballistic through a nano-wire like in a two-dimensional electron gas, while phonons are absorbed in the surrounding material. The natural superlattice of the Ruddlesden-Popper phases (SrTiO3)n-(SrO)m combines the semiconducting behavior of SrTiO3 with the low thermal conductivity of SrO and is a promising thermoelectric material.