Measurements of the 10GHz microwave surface resistance of dense MgB2 wire and pellet are reported. Significant improvements are observed in the wire with reduction of porosity. The data lie substantially above the theoretical estimates for a pure BCS s-wave superconductor . However the Rs(20K) of the wire is an order of magnitude lower than that of polycrystal YBa2Cu3O6.95 and matches with single crystal YBa2Cu3O6.95.The results show promise for the use of MgB2 in microwave applications.
@article{arxiv.cond-mat/0103422,
title = {Microwave properties of superconducting $MgB_{2}$},
author = {N. Hakim and P. V. Parimi and C. Kusko and S. Sridhar and P. C. Canfield and S. L. Bud'ko and D. K. Finnemore},
journal= {arXiv preprint arXiv:cond-mat/0103422},
year = {2009}
}