Microwave Properties of Ba(0.6)K(0.4)BiO(3) Crystals
arXiv:cond-mat/0405140 · doi:10.1140/epjb/e2004-00323-6
Abstract
We report on field-induced variations of the microwave surface resistance at 9.6 GHz of Ba(0.6)K(0.4)BiO(3) crystals. Energy losses have been investigated as a function of the static magnetic field in the range of temperatures 4.2 K - Tc. By analyzing the experimental results in the framework of the Coffey and Clem model we determine the temperature dependence of the first-penetration field, upper critical field and depinning frequency. The results show that the pinning energy of this bismuthate superconductor is weaker than those of cuprates.
6 pages, 8 embedded figures