Thermal diffusivity of HTSC ceramics of Y-Ba-Cu-O system

The article presents the results of investigating thermal diffusivity of HTSC ceramics of YBa2Cu3O7-x content produced by the sintering method in 80-200 K temperature range. Sample density - 5.1 g/cm3, temperature of transition into superconducting state ∼90 K (ΔTc=1.5 K). The method of plane temperature waves (Angstrom method) was used to measure thermal diffusivity. The results of measuring thermal diffusivity of sintered YBa2Cu3O7-x ceramics are presented. Slight peculiarity manifests in self dearily in the vicinity to c and corresponds to λ-type peculiarity of heat capacity. Certain local maximum κ(T) is observed when heated above 100 K. It is noted that nonmonotonic behaviour of thermal diffusivity at 100-110 K corresponds to nonmonotonic. Thermal conductivity in this region but has another sign. The physical nature of such behaviour is not clear so par and can be a subject of further investigations