Effect of twins in Ni substrates on the microstructure of La2Zr2O7 films for coated conductors

Sarah Petit (1) , Sébastien Pairis (2) , Mélissa Mikolajczyk (1) , Luc Ortega (3) , Jean-Louis Soubeyroux (4) , Philippe Odier (4)

1 CRETA - Consortium de Recherches pour l'Emergence des Technologies Avancées
2 NEEL - C2MA - Croissance Cristalline et MicroAnalyse
3 NEEL - X'Press - X'Press : diffraction et hautes pressions
4 NEEL - MagSup - Magnétisme et Supraconductivité

La2Zr2O7 (LZO) films were deposited by chemical solution deposition on Ni95Wi5 Rolling Assisted Bi-axially Textured substrates to be used in YBa2Cu3O7 (YBCO) coated conductors. These LZO films were proved of good qualities for YBCO deposition by Metal Organic Chemical Vapour Deposition that is an economic process. The mosaic of LZO films is only slightly degraded by the process of grain-to-grain epitaxial transfer (16% with respect to that of the substrate). The film is composed of small crystallites (20 - 40 nm) and larger anomalous crystallites (100 - 400 nm) found in great number in transferred twins from the substrate. The anomalous crystallites are poorly crystallised or amorphous and contain more C than areas with normal crystallites. High temperature in-situ X ray shows a sudden crystallisation at 860°C that does not seems to involve a solid state reaction. The anomalous crystallites are analysed to result from a locally enhanced barrier to nucleation and might reveal sor characteristics of the crystallization.

Mots clés: lanthanum zirconate; epitaxy; thin films; coated conductors

Domaines: Matériaux

Sarah Petit, Sébastien Pairis, Mélissa Mikolajczyk, Luc Ortega, Jean-Louis Soubeyroux, et al.. Effect of twins in Ni substrates on the microstructure of La2Zr2O7 films for coated conductors. Thin Solid Films, 2012, 531, pp.545-551. ⟨10.1016/j.tsf.2012.11.054⟩. ⟨hal-00814799⟩