Distribution of $J_{\rm c}$ in Rectangular-Shaped YBCO Films Prepared by MOD Using Various Coating Methods

Abstract

12 cm-long rectangular MOD-YBa <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sub> (YBCO) films were prepared by MOD on R-plane sapphire substrates with an evaporated-CeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> buffer layer. The substrates were coated with a fluorine-free solution by two methods; spin coating and wire-bar coating. Distribution of inductive J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> of the spin-coated and wire-bar-coated Alms was investigated. In the inductive measurement of superconducting YBCO films, the data are presumed to be affected by film edges if the width is comparable to the diameter of the probe coil. However, the present results showed that the edge effect is less significant if the coil does not cross the film edges and that the inductive J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> agrees well with the transport J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> . YBCO films with high J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> were obtained by both the coating methods. At present, the J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> values and uniformity of J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> in YBCO films prepared by spin coating were higher than those by wire-bar coating.