Static and dynamic structures of liquid tellurium containing alkalis

The results of measurements of electrical conductivities, EXAFS, neutron diffraction, neutron inelastic scattering and neutron quasielastic scattering for liquid K-Te and Rb-Te mixtures are reported. The metallic liquid Te is transformed to a semiconducting bonding state and from the semiconducting to an ionic bonding state with addition of alkali elements. Neutron diffraction data suggest that the chain structure of liquid Te remains even in the Te mixtures containing 20 at. % K and Rb, and that the distance between Te and alkalis are 3.6 Angstrom for liquid K-Te mixture and 3.8 Angstrom for liquid Rb-Te mixture. The coordination number of Te around alkali atoms is estimated to be four, which is supported by EXAFS analysis. It is found that the addition of alkalis to liquid Te strengthens the Te intrachain interaction.