Low-thermal-conductive DyBaCuO bulk superconductor for current lead application

The thermal conductivity kappa(T), thermal diffusivity alpha(T) and thermal dilatation dL(T)/L of the DyBaCuO bulk superconductor have been measured. The ab-plane K of the bulk at 50 K is about one third of that of the YBaCuO bulk, and moreover, the superconducting characteristics (critical current density J(c) and superconducting transition temperature T-c) compare favorably with those of the YBaCuO bulk. The current-voltage (I-V) characteristics of the current lead fabricated from DyBaCuO bulk and the durability against the thermal quenching are as good as those of the YBaCuO lead. The DyBaCuO bulk is a promising material for the power current lead use to be replaced for the YBaCuO bulk.