Fabrication of biaxially aligned YBa 2Cu 3O 7− x thin films on glass substrates

Abstract

Biaxially aligned YBa 2Cu 3O 7− x thin films have been fabricated on glass substrates with an in-plane aligned yttria-stabilized zirconia (YSZ) buffer layer. Ion-beam assisted pulsed laser deposition was used to prepare the YSZ buffer layers on amorphous glass substrates. The YSZ films deposited at room temperature exhibited (001) orientation, whereas at temperatures higher than 300°C, YSZ grew with high degree of (111) orientation. Both the (001) and (111) YSZ films were biaxially aligned. YBa 2Cu 3O 7− x films deposited using pulsed laser deposition on biaxially aligned (001) YSZ on glass were highly c-axis oriented and strongly a- b plane aligned. A critical temperature T c0 ( R = 0) of 87.1 K was routinely achieved and J c was in the range of ∼ 10 4 A/cm 2. The limitation in J c was found to be due to microcracks in the YBCO film caused by the tensile stress resulting from the thermal expansion mismatch between the glass and YBCO. The results suggest that glass with a better thermal expansion match to YBCO would lead to higher J c values.