Thermal conductivity of polycrystalline YBa2Cu4O8 and the phonon transport model

✍ Scribed by B. Sundqvist; B.M. Andersson

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 264 KB
• Volume: 235-240
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)91913-5

✦ Synopsis

We have measured the thermal conductivity ~: of bulk YBa2Cu40 s (1-2-4) between 30 and 310 K and at pressures p up to 1 GPa. At p = 0, ~: = 10 Wm-IK -1 near 100 K, twice that of sintered YBa2Cu3OT. s (1-2-3). ~¢ also decreases with increasing T more rapidly than in 1-2-3, to 7.4 Wm'IK "1 at 300 K. Under pressure, ~: increases slowly with p above 150 K, but dvddp decreases at lower T. Our results are in excellent agreement with a semi-classical model for phonon thermal conductivity, provided we assume significant charge transfer with pressure. The calculated phonon mean free path is much larger than the lattice spacing at all T.