Thermal conductivity of YBa2Cu4O8 under high pressure

• Published in: Physica. C, Superconductivity Superconductivity, 1993-10, Vol.216 (1-2), p.187-194
• Main Authors: ANDERSSON, B. M, SUNDQVIST, B
• Format: Article
• Language: English
• Subjects: 1-2-4; ceramic; charge transfer; Condensed matter physics; Condensed matter: electronic structure, electrical, magnetic, and optical properties; electron-phonon scattering; Exact sciences and technology; Fysik; high pressure; impurity scattering; Kondenserade materiens fysik; NATURAL SCIENCES; NATURVETENSKAP; phonon transport; Physics; Properties of type I and type II superconductors; Superconductivity; superconductor; Supraledning; Thermal conductivity; thermal diffusivity; Transport properties (electric and thermal conductivity, thermoelectric effects, etc.); YBa2Cu4O8
• ISSN: 0921-4534; 1873-2143; 1873-2143
• DOI: 10.1016/0921-4534(93)90652-7

The thermal diffusivity a of YBa2Cu4O8 (1-2-4) has been measured as a function of pressure p and temperature T over the range 85<T<310 K and up to 1 GPa (10 kbar). From the data obtained we have calculated the pressure dependence of the thermal conductivity κ as a function of T. κ increases slowly with increasing p above 150 K but decreases below this value. Most of the high-T increase with p is caused by an increase in the electronic thermal conductivity κe. For the phonon thermal conductivity, which dominates κ in 1-2-4, we find that charge transfer with p causes a strong increase in electron-phonon scattering with p, while the p dependence of the boundary scattering and phonon-phonon scattering is in reasonable agreement with the behaviour predicted by simple models.