We observed vortices with a modified Bitter method by evaporating nickel as the medium of decoration, in film and QMG (which are made with the quench-and-melt-growth method) YBa2Cu3 (YBCO) samples. The temperature range of observation was from 25 K to 90 K, and the external magnetic field was 2 ml. Consequently, we found that the vortex structures of these samples were stable from 25 K to near the critical temperature (∼90 K). The density of vortex was almost three times larger than that estimated from the external magnetic field. This suggests that the vortex motion may be hopping during nickel evaporation.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering