Flux separation in crystal growth of YBa2Cu3O7 - x

Dynamic roughening of the magnetic flux landscape in YBa2Cu3O7−x

We study the magnetic flux landscape in YBa2Cu3O7−x thin films as a two dimensional rough surface. The vortex density in the superconductor forms a self-affine structure in both space and time. This is characterized by a roughness exponent α = 0.76(3) and a growth exponent β = 0.57(6). This is due to the structure and distribution of flux avalanches in the self-organized critical state, which i...

EFFECTS OF EPITAXIAL STRAIN ON THE GROWTH MECHANISM OF YBa2Cu3O7−x THIN FILMS IN [YBa2Cu3O7−x/PrBa2Cu3O7−x] SUPERLATTICES

We report on the growth mechanism of YBa2Cu3O7−x. Our study is based on the analysis of ultrathin, YBa2Cu3O7−x layers in c-axis oriented YBa2Cu3O7−x / PrBa2Cu3O7 superlattices. We have found that the release of epitaxial strain in very thin YBCO layers triggers a change in the dimensionality of the growth mode. Ultrathin, epitaxially strained, YBCO layers with thickness below 3 unit cells grow ...

An All Sol-Gel Process for the Heteroepitaxial Growth of YBa2Cu3O7-x/LaNiO3/YBa2Cu3O7-x Tri-layer

The preparation of a YBa2Cu3O7−x/LaNiO3/YBa2Cu3O7−x sandwich structured film on a LaAlO3 (100) substrate by a sol-gel method was investigated. YBa2Cu3O7−x/LaNiO3/YBa2Cu3O7−x tri-layer heterostructures with different epitaxial characteristics can be deposited by controlling the heat treatment temperature. X-ray diffraction and transmission electron microscopy results show that the bottom YBCO fi...

FLUX PINNING ENHANCEMENT IN YBa2Cu3O7-x FILMS FOR COATED CONDUCTOR APPLICATIONS (POSTPRINT)

Dynamics of the dendritic flux instability in YBa2Cu3O7-δ films

– We have studied the dynamics of magnetic-flux avalanches in superconducting YBa2Cu3O7−δ films by means of a fast magneto-optic pump-probe technique. Two regimes of propagation are found: in regime I, directly after the nucleation of the avalanches by a femtosecond laser pulse, the velocity v of the flux dendrites depends strongly on the magnetic field, and values of v up to 180 km/s are obser...