Preparation and characterization of {100}001 cube textured Ag substrates for in-plane oriented HTS tapes

• Published in: Superconductor science & technology 1999-09, Vol.12 (9), p.624-632
• Main Authors: Suo, HongLi, Genoud, Jean-Yves, Triscone, Gilles, Walker, Eric, Schindl, Michael, Passerini, Reynald, Cléton, François, Zhou, MeiLing, Flükiger, René
• Format: Article
• Language: English
• ISSN: 0953-2048; 1361-6668
• DOI: 10.1088/0953-2048/12/9/309

A systematic study of texturing mechanisms in pure Ag is presented, the goal being to obtain a cube textured {100} < 001 > tape that can be used as a substrate for superconducting coated conductors. It is shown that a sharp cube texture can be produced after pre-heated deformation and recrystallization. Optimal parameters are detailed. 99.99% pure Ag powder is used as starting material. Fine grained (15 mu m) Ag ingots are pre-heated at 100 degree C before standard cold rolling. The effect of pre-heating on deformation texture is to change the main texture from the brass orientation {110} < 112 > to the Goss {110} < 001 > one. The presence of a copper-type texture with relatively high values of the ODF (oriented distribution function) after the 100 degree C pre-heated deformation can be understood as a slight increase of the stacking fault energy of Ag during the pre-heated deformation. The optimal annealing is achieved at 700 degree C for 30 min in a primary vacuum. This leads to a sharp cube texture. The FWHM values of the three x-ray pole figures are, at no more than 10 degree , the smallest ever reported for cube textured Ag tapes. The formation of cube texture is interpreted in terms of orientation nucleation and orientation growth theories that play a common role during the texturing process. The stability of cube texture at high temperature up to 900 degree C indicates that the tapes are suitable for epitaxial growth of superconducting oxides.