Influence of growth rate on the structural orientation of YBCO superconducting films

Abstract

Superconducting films were grown by DC magnetron sputtering of a stoichiometric target at varied pressure (p =5-100 Pa) of argon/oxygen mixture and substrate (MgO(100), , ) temperature K. Film axis orientation and crystal quality were investigated using Raman spectroscopy and medium energy ion backscattering technique. The pressure and substrate temperature determine the growth rate and the crystallographic orientation of YBCO films. At a critical value of about 1.5-2.0 nm , films of mixed orientation are formed. At higher than the critical value, the films show orientation, and growth at rates lower than 1.5 nm gives -oriented films. Correspondingly, at low nm , truly epitaxial films are formed and this kind of structure may be preserved up to 1-m film thickness. A kinetic study allowed estimating the coefficients of surface diffusion in the indicated temperature range: , and . The data obtained are discussed and compared with the known values.

Precursor Evolution and Nucleation Mechanism of YBa2Cu3Ox Films by TFA Metal−Organic Decomposition

“…Various forms of the overall reaction have been proposed in the literature, − but there is ample evidence that the reaction path to the final epitaxial YBCO film is, however, complex, both chemically and topologically. The growth rate of the YBCO film is governed by T , P (H 2 O), and total pressure, , and it has been demonstrated that a careful adjustment of the process parameters is essential to control the microstructure and therefore the critical currents of the films …”

Microstructure of epitaxial YBa2Cu3O7−δ thin films grown on Pb(Mg1/3Nb2/3)0.7Ti0.3O3 substrates

“…From the energy standpoint, we believe that the inclined DWs are a consequence of competition between the elastic energy of a propagating surface, tending to keep it flat, and the DW energy. As the growth rate of a-b plane is much higher than that along the c-axis in YBCO [16], the a-axis oriented domains grow faster in the normal direction of the interface than the surrounding c-axis epitaxial film. This will cause convexes at the surface of the film, which may increase the surface energy.…”

Fabrication process and noise properties of antenna-coupled microbolometers based on superconducting YBCO films

“…As known, the c ⊥ -oriented structure is a metastable phase of the YBa 2 Cu 3 O 7 compound [22,29,32]. Formation of c -microblocks oriented in a different way leads to the development of block boundaries, i.e.…”