Superconductive and structural properties of plasma sprayed YBaCuO and BiSrCaCuO layers

In this paper we discuss the influence of melt texturing on the structural and superconductive properties of plasma sprayed Bi2Sr2CaCu2Ox and YBa2Cu3O3 layers on stainless steel and nickel substrates with a Yttria stabilized Zirconia (YsZ) buffer layer. The YBaCuO interacts with the YsZ during melt texturing whereas the amount of texture is relatively small. Application of the quench melt growth technique gives a better texture but there still is a strong interaction with the YsZ. For both heat treatments crack formation occurs in the YBaCuO layers, leading to relatively small critical current densities. The BiSrCaCuO layers are treated at lower temperatures and have a smaller interaction with the YsZ. Also crack formation during the heat treatment is not observed. For BiSrCaCuO layers the best superconductive properties (at 10 K) are are found for texturing in a gradient of 15 K/cm with maximum temperatures ranging from 910–940 °C and velocities through the gradient ranging from 50–500 mm/h.