Motional correlation time of dilute111Cd impurities in liquid S and Se

Abstract

Abstract : The elements sulfur, selenium and tellurium have been extensively studied in the liquid state on account of their interesting electrical and physical properties. According to current understanding, these materials exist in the liquid in the form of chain- or ring-shaped molecules, depending on the material and temperature range. Their electrical properties are strongly influenced by bonding irregularities in the predominant structure, such as chain ends, branches or impurities. As temperature increases, the relative concentration of these effects in bonding also increases, with a concomitant increase in the conductivity. Physically, the viscosity of the liquids decreases rapidly with increasing temperature, suggesting that the liquids undergo marked structural changes (ring-chain transformation, and shortening of chain length with increasing temperature, for example). Although powerful tools such as NMR, neutron scattering, and viscosity measurements, among many others, have been used to study these materials, a complete understanding of the dynamical behavior of these liquids is still lacking. We describe here an application of time-differential perturbed angular correlation (TDPAC) to the study of molecular dynamics in liquid S and Se.