Ellipsometric Spectroscopy of Liquid Selenium-Thallium Mixtures

• Published in: Journal of the Physical Society of Japan Vol. 77; no. 4; p. 44708
• Main Authors: FUJII, Kensuke, OHMASA, Yoshinori, TAKAHASHI, Shin, KATAYAMA, Takuya, MAKINO, Wataru, YAO, Makoto
• Format: Journal Article
• Language: English
• Published: Tokyo Institute of Pure and Applied Physics 2008; Physical Society of Japan; The Physical Society of Japan
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conductivity of specific materials; Electronic transport in condensed matter; Exact sciences and technology; Liquid semiconductors; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Physics; Liquid state; Thallium; Electrical conductivity; Spectroscopic ellipsometry; thermopower; Dielectric function; Energy gap; ellipsometry; conductivity; liquid; Temperature effects; Thermoelectric power; mixture; Chemical composition; Selenium; Activation energy; Liquid mixtures
• ISSN: 0031-9015; 1347-4073
• DOI: 10.1143/jpsj.77.044708

Complex dielectric function for liquid Se-Tl mixtures has been obtained by ellipsometric measurements at temperatures between 300 and 500 °C. The optical gap decreases rapidly with increasing Tl-concentration in the low concentration region less than 15 at. % Tl, while it remains nearly constant for higher concentrations up to 40 at. % Tl. A long-standing problem of the discrepancy between the activation energies of the electrical conductivity and thermopower can be resolved by considering the temperature dependence of the energy gap precisely.