It has been recently shown that CSD films can be grown by direct precurson solution deposition on as-rolled, i.e., without cube orientation, metallic substrate. (LZO) and CeO2 are of particular interest as they enabled an all-chemical route for the fabrication of YBCO coated conductor. The growth of oriented buffer layers by chemical solution deposition (CSD) on cube-textured Ni-based substrate is a key point for the development of low-cost YBa Our experiments indicate that the motion of grain boundaries occurring during secondary recrystallization process does not affect the quality of LZO film. In several samples the substrate underwent secondary recrystallization.
For example, La2Zr2O7 (LZO) film with a high degree of epitaxy was grown by metal-organic decomposition (MOD) at 1000 ☌ on pure copper substrate. The combined use of a small initial grain size and a recrystallization two-step annealing (TSA) drastically reduced the presence of abnormal grains in pure copper tapes.Īnother way to overcome the limitation imposed by the formation of abnormal grains is to deposit a buffer layer at temperatures where secondary recrystallization does not occur. To avoid the formation of abnormal grains the effect of both grain size adjustment (GSA) and recrystallization annealing was analyzed.
The onset of secondary recrystallization (i.e., the occurrence of abnormal grains with unpredictable orientation) in pure copper substrate was observed within the typical temperature range required for buffer layer and YBCO processing (600–850 ☌). However, one of the main drawbacks concerning the use of pure copper cube-textured substrates for YBCO coated conductor is the reduced secondary recrystallization temperature. It is well known that the recrystallization texture of heavily cold-rolled pure copper is almost completely cubic.
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