ISSN:
1573-7357
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
We have measured critical current densities J c , of superconducting copper molybdenum sulfide prepared by sputtering onto heated sapphire substrates. In addition, we have examined the samples with SEM, TEM, electron microprobe, and x-ray diffraction techniques. Critical currents were measured as a function of external magnetic field and as a function of temperature and sample preparation conditions. We find that a scaling law P = CB c2 n f(b) describes our results, where P is the pinning force per unit volume, B c2 is the upper critical field, b is the reduced field b ≡ B/B c2, f(b) is a function of b only, and C is a constant of proportionality. Our results fit the flux shearing model of Kramer from relatively low b (≃0.5) to b = 1. Furthermore, applying this model to PbMo6S8, we estimate the critical current density as a function of magnetic field. For example, we predict J c 108 A/m2 at 26 T. From analysis of all experimental data on our samples, we conclude that flux pinning is mainly on excess Mo metal. The Mo is present as a second phase in the predominantly Chevrel-phase Cu x Mo6S8, while all the Cu metal is included in the Chevrel phase.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00116213
Permalink