Optical and acoustic electron-phonon coupling in Ho and Tb dihydrides and dideuterides

• Published in: Solid state communications 1985-01, Vol.54 (9), p.807-810
• Main Authors: Lucasson, A., Vajda, P., Burger, J.P., Daou, J.N.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electrical and thermal conduction in crystalline metals and alloys; Electronic conduction in metals and alloys; Electronic transport in condensed matter; Exact sciences and technology; Physics
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/0038-1098(85)90291-1

We present detailed measurements of the electrical resistivity for terbium and holmium dihydrides and dideuterides. An analysis of the thermal variation, ϱ( T), permits to separate two contributions, one stemming from the acoustic or host metal ion vibration and a second which is related to the optical H (or D) vibrations and which is strongly isotope dependent. The thermal variations can be reasonably well represented by a Debye spectrum as concerns the acoustic phonons and by an Einstein spectrum as concerns the optical phonons. We find also that the strength of the electron-phonon coupling is much weaker for the optical phonons as compared to the acoustic ones, in agreement with recent estimates from the theory.