Processing Dependence of Texture, and Critical Properties of YBa₂Cu₃O_7−δ Films on RABiTS Substrates by a Non‐Fluorine MOD Method

Abstract

YBa 2 Cu 3 O 7Àd (YBCO or Y123) films on rolling-assisted biaxially textured substrates (RABiTS) were prepared via a fluorinefree metallorganic deposition (MOD) through spin coating, burnout, and high temperature anneal. The effects of substrate texture and surface energy of the CeO 2 cap layer were investigated. Except for the commonly accepted key factors, such as the textures of substrate and buffer layers, we found some other factors, for example, the deposition temperature of the cap layer, are also critical to the epitaxial growth of Y123 phase. With the CeO 2 cap layer deposited at relative high temperature of 7001C, a critical current density, J c , over 1 MA/cm 2 has been demonstrated for the first time on Ni-RABiTS by a fluorine-free MOD method. Whereas for samples with CeO 2 cap layers deposited at a lower temperature of 6001C, even though XRD data showed a better texture on these buffer layers, texture degradations of YBCO grains under the optimized processing conditions were observed and a lower oxygen partial pressure around 40 ppm was necessary for the epitaxial growth of Y123 phase. As a result, J c fell to 0.45 MA/cm 2 at 77 K. The observed phenomena points to the change of surface energy and reactivity of the CeO 2 cap layer with respect to the CeO 2 deposition temperature. In this paper, the YBCO phase diagram was also summarized. J ournalJ. Am. Ceram. Soc., 89 [3] 914-920 (2006)

Fluorine-free sol–gel preparation of YBa2Cu3O7−x superconducting films by a direct annealing process

“…The underlying reason is thought to be that during the heat treatment process the stable BaCO 3 phase is easily formed, which blocks the formation of the YBCO phase and the transportation of superconducting current. To overcome this, metal acetylacetonates [14], metal naphthenates [15], metal trimethylacetates [16][17][18], and metal citrates [19], have been selected as precursors by some groups. And polymerbased YBCO precursor solution [20][21][22][23] has also been invented.…”

Chemical Solution-Derived YBa2Cu3.3 O 7-d /CuO Multilayer Structure-Coated Conductors on Oxide-Buffered Metallic Tapes

“…However, the traditional trifluoroacetate-metal organic deposition (TFA-MOD) method using the all-TFA solution requires more than 10 h for the process of each layer [10,11]. In practice, fast production and thicker films can be realized by reducing the fluorine content, which has been carried out by many researchers in recent decades [12][13][14][15].…”

Preparation of YBa2Cu3O7-δ Micropatterns Using Metal–Organic Deposition with Electron Beam

“…High-quality epitaxial films of YBCO with a large area and high critical current density have been reported. [5][6][7] MOD using trifuruoroacetate (TFA-MOD) has also attracted attention because of the higher critical current. 8,9) Recent progress in the applications of TFA-MOD was prominent in obtaining thicker films 10,11) and wires more than 500 m long.…”