TEM observations of Gd2Zr2O7 films formed by the ion-beam-assisted deposition method on an Ni-based alloy

Gd2Zr2O7 films were formed by the ion-beam-assisted deposition (IBAD) method on an Ni-based alloy. Cross-sectional and plan-view specimens of the films were prepared for transmission electron microscopy investigation and microstructural characterization. The thicknesses of the Gd2Zr2O7 films were less than 1.3 mum. During initial formation of the films, tiny grains nucleated close to the Ni-based alloy, followed by gradual formation of a columnar texture composed of fine <001> aligned grains perpendicular to the Ni-based alloy interface. However, dark-field image taken under (g) over right arrow = (440) indicated that the in-plane mosaic spread of the columnar texture did not improve as much as the [001] tilt angle. However, examination of the Gd2Zr2O7 film surfaces revealed that the interfaces between columns were not well defined. Furthermore, a CeO2 film deposited on a 1.3 mum thick Gd2Zr2O7 film by the pulsed laser deposition (PLD) method contained less in-plane mosaic spread than the Gd2Zr2O7 film alone. PLD-CeO2/IBAD-Gd2Zr2O7 films are therefore considered promising candidates for use as buffer layers in superconductor tapes. (C) 2003 Elsevier B.V. All rights reserved.