Vortex dynamics and possible vortex states just below the vortex-glass phase
Abstract
We have measured current-induced voltage noise SV of thick amorphous MoxSi1-x films in various fields H from zero to high fields near the vortex-glass (VG) transition Hg . Irrespective of temperature T , SV is highest in the Meissner phase (H<Hc1) . With applying H that exceeds Hc1 , SV decreases abruptly and falls to the background level. With further increasing H , SV then starts to rise at characteristic field HLg0(≪Hg) and the broad peak resulting from a plastic-flow motion of VG occurs before Hg is approached. Combined with the SV data for the Corbino disk, we suggest that the edge-contamination effects reported in the clean NbSe2 single crystals are not important in our disordered films. Within the T range studied, HLg0(T) shows an increase on cooling, which is different from the T -independent disorder-driven transition. We interpret the field regime Hc1(T)<H(T)<HLg0(T) as the vortex state different from the VG phase.
- Publication:
-
Physical Review B
- Pub Date:
- July 2004
- DOI:
- 10.1103/PhysRevB.70.014509
- Bibcode:
- 2004PhRvB..70a4509O
- Keywords:
-
- 74.25.Dw;
- 74.40.+k;
- 74.78.Db;
- Superconductivity phase diagrams;
- Fluctuations;
- Low-T<sub>c</sub> films