Beschreibung:
<jats:title>Abstract</jats:title><jats:p>Measurements of the thermal diffusivity<jats:italic>D</jats:italic>on crystals of the highly anisotropic organic semiconductor TEA(TCNQ)<jats:sub>2</jats:sub>are reported. These measurements are made using a heat pulse method. For the crystal axis 1 parallel to the TCNQ columns and associated with the largest component σ<jats:sub>1</jats:sub>of the electrical conductivity,<jats:italic>D</jats:italic><jats:sub>1</jats:sub>is 1.6×10<jats:sup>−3</jats:sup>cm<jats:sup>2</jats:sup>s<jats:sup>−1</jats:sup>at 300 K increasing to 2.7×10<jats:sup>−3</jats:sup>cm<jats:sup>2</jats:sup>s<jats:sup>−1</jats:sup>at 200 K. The thermal conductivity<jats:italic>k</jats:italic><jats:sub>1</jats:sub>is evaluated to 4 mW cm<jats:sup>−1</jats:sup>K<jats:sup>−1</jats:sup>at 300 K with an estimated electronic contribution of only 1%. The phonon mean free path at 300 K is extremely small l<jats:sub>1</jats:sub>≈ 2 Å, of the order of the shortest distance between the TCNQ molecules in a column. It is thus expected to be almost constant at this temperature, a result which is also suggested from the observed<jats:italic>T</jats:italic>dependence of<jats:italic>D</jats:italic><jats:sub>1</jats:sub>. For the crystal axis 2 associated with the intermediate component σ<jats:sub>2</jats:sub>of the electrical conductivity,<jats:italic>D</jats:italic><jats:sub>2</jats:sub>is 2.3×10<jats:sup>−3</jats:sup>cm<jats:sup>2</jats:sup>s<jats:sup>−1</jats:sup>at 200 K. From these results it appears that the thermal diffusivity<jats:italic>D</jats:italic>is not markedly anisotropic in TEA(TCNQ)<jats:sub>2</jats:sub>, as it may be expected from a phonon contribution only.</jats:p>