Abstract
The infrared reflection spectra of single crystal lithium hydride, lithium deuteride, lithium-6 hydride, and lithium-7 hydride have been measured and analyzed. The long wavelength limits of the optical lattice vibrational frequencies have been determined and used to find the static dielectric constants and Szigeti effective charges of all the isotopic variations studied. It is found that the square of the longitudinal (or transverse) frequency is inversely proportional to the reduced mass of the ion pairs forming the crystal. The Szigeti effective charge for LiH, e s ∗ = (0.53±0.02)e , is qualitatively accounted for by the Dick and Overhauser shell model for the vibrating ions. A slight isotope effect on the e s ∗ is noted in LiD and the difference in effective charges is interpretable within the framework of the shell model.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call