In-Plane Orientation Control of C-Axis Oriented YBa 2Cu 3O 7-δ Films on MgO Substrates by BaSnO 3 Buffer Layers

Abstract

A new BaSnO3 buffer layer is proposed for controlling the in-plane orientation of YBa2Cu3O7-δ films grown on MgO substrates. BaSnO3 buffer layers and YBa2Cu3O7-δ films are grown by pulsed laser deposition. 45° grain boundaries in YBa2Cu3O7-δ films grown on MgO (001) substrates, which are fatal defects for microwave device applications, are eliminated using the BaSnO3 buffer layer. YBa2Cu3O7-δ films grown at an optimum growth temperature of 710°C on BaSnO3 buffer layers on MgO (001) substrates show lower surface resistance (RS) than those on MgO (001) substrates without BaSnO3 buffer layers.