Anisotropic thermal diffusivity and conductivity of YBCO(123) and YBCO(211) mixed crystals. I

• Published in: Japanese Journal of Applied Physics Vol. 33; no. 9A; pp. 4965 - 4970
• Main Authors: FUJISHIRO, H, IKEBE, M, NAITO, T, NOTO, K, KOHAYASHI, S, YOSHIZAWA, S
• Format: Journal Article
• Language: English
• Published: Tokyo Japanese journal of applied physics 01.09.1994
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Granular, melt-textured, amorphous and composite superconductors; Inhomogeneous superconductors and superconducting systems; Physics; Properties of type I and type II superconductors; Superconductivity; Transport properties (electric and thermal conductivity, thermoelectric effects, etc.); Temperature dependence; Inorganic compounds; Ternary compounds; Transition element compounds; Thermal diffusivity; Experimental study; Specific heat; Anisotropy; Barium oxides; High-Tc superconductors; Thermal conductivity; Microstructure; Copper oxides; Inhomogeneous materials; Yttrium oxides
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.33.4965

The anisotropic thermal diffusivity α of the highly c -axis-oriented Y–Ba–Cu–O bulk superconducting crystals has been measured quasi-simultaneously with the thermal conductivity κ. The estimated values of the specific heat C by use of α and κ values parallel and perpendicular to the c -direction agreed with each other. In these crystals prepared by the modified melt texture growth (MMTG) method, fine Y 2 BaCuO 5 particles are dispersed in the YBa 2 Cu 3 O 7- x superconducting matrix phase. Based on a simple model, the thermal diffusivity and the specific heat of the YBa 2 Cu 3 O 7- x matrix phase are separated using independently measured data of a Y 2 BaCuO 5 polycrystal. The influence of Y 2 BaCuO 5 particles on the thermal properties of the mixed crystals is discussed.