Nonvacuum-based deposition techniques for superconducting ceramic coatings

Abstract

The widespread use of vacuum-based techniques for the deposition of ceramic coatings with specific electric, magnetic, optical, and mechanical properties is well established in the research environment, and some of them have been implemented in a variety of industrial processes. However, obtaining uninterrupted deposition at high speed, increasing flexibility in composition and in film thickness, and attaining independence of geometric constraints are areas in which many vacuum techniques will need sustained development in order to answer industrial demands. The development of the next generation of deposition methods, which could alleviate some of these shortcomings and which are based on deposition under atmospheric environment and from aqueous precursor materials, is a real challenge for the community of solid-state chemists and delineates the subject of this overview.

Complexation behavior in aqueous edta sol-gel systems for the synthesis of YBa2Cu3O7-x high-temperature superconductors

“…Even at high concentrations, these metal ions remain captured in the so-called microcavities and the homogeneity is presented in a non-classical gel state. [8][9][10][11][12][13][14] The introduction of a suitable ligand and an adjustment of the pH level are necessary to obtain a stable system and to avoid precipitation. A strong ligand such as edta is of preferable use in the synthesis of HTSC oxides.…”

Influence of Morphology and Texture of CeO2 on YBa2Cu3O7 (YBCO) Growth and BaCeO3 Formation in Solution‐Derived Synthesis

“…Therefore, a great deal of attention has been given to the development of coated conductors that uses a low-cost deposition technique [i.e., chemical solution deposition (CSD) for buffer layers and superconducting coatings on flexible metallic tapes]. [1][2][3] This route towards the synthesis of ceramic materials gives an improved control of material characteristics by adjusting the chemistry of the system. As it is a nonvacuum technique and does not require ultrapure precursor targets or substantial facility investments, it contributes to the economic applicability of these innovative cessing, a combination of a slow calcination ramp with a high sintering ramp, short sintering dwell time and a low oxygen partial pressure during the synthesis resulted in a root mean square roughness below 3 nm for AFM analysis, a [111] to [002] ratio of 1 to 90 in X-ray diffraction and well-defined patterns in reflection high-energy electron diffraction (RHEED) analysis of the CeO 2 surface.…”

CeO2 Buffer Layers for HTSC by an Aqueous Sol‐Gel Method – Chemistry and Microstructure

“…chemical solution deposition on more flexible metallic tapes. [3,4] In order to minimize chemical interactions and optimize crystal growth, a buffer layer architecture of sufficient tion was studied by potentiometric titrations. The main parameters influencing the texture seem to be the ambient Ar-(5 %)H 2 atmosphere and the thickness of the synthesized buffer layers.…”

“…Recent research into new generation high J c YBa 2 Cu 3 O 7 -coated conductors shows promising applicability in electrical power and electronic appliances. [7,8] We have explored a multi-layered architecture consisting of both CeO 2 and La 2 Zr 2 O 7 . A schematic cross-section of a coated conductor is given in Figure 1.…”

“…From a chemical point of view sol-gel chemistry is based on the hydrolysis and condensation of metal complexes. [3,[9][10][11][12][13] In the aqueous method described in this work, the metal salts are dissolved in water with formation of unstable metal aqua complexes. Hydrolysis of these species leads to precipitation of metal hydroxides.…”