The results of a (weak) DC magnetic field induced excess resistivity in granular high-temperature superconductors are analyzed. Assuming a random mixture of superconducting and normal regions, the two characteristic excess resistivity peaks are interpreted as originating from two different mechanisms: the higher temperature peak in excess resistivity is attributed to a distribution of the critical temperature in individual grains affected by the applied magnetic field, this results in a quasi-percolative normal current energy dissipation. The lower temperature wide peak is attributed to an interplay between strong pinning due to the spatial inhomogeneity of the condensation energy on one hand and to the onset of proximity effect with decreasing temperature, on the other. The results obtained with various concentrations of Ag admixture and under varying magnetic field are consistent with the predictions of this model.
|Number of pages||7|
|Journal||Physica C: Superconductivity and its Applications|
|State||Published - 20 Oct 1998|
Bibliographical noteFunding Information:
L.B. acknowledges support from German–Israeli Foundation (GIF) and from the Israel Academy of Sciences.
- Quasi-percolative normal current dissipation
- Weak DC magnetic field