Upper critical field, penetration depth, and depinning frequency of the   novel high-temperature superconductor LaFeAsO$_{0.9}$F$_{0.1}$ studied by   microwave surface impedance
  Temperature and magnetic field dependent measurements of the microwave surface impedance of superconducting LaFeAsO$_{0.9}$F$_{0.1}$ (\Tc $\approx$ 26K) reveal a very large upper critical field ($B_{\rm c2} \approx 56$T) and a large value of the depinning frequency ($f_{0}\approx 6$GHz); together with an upper limit for the effective London penetration depth, $\lambda_{\rm eff} \le 200 \rm nm$, our results indicate a strong similarity between this system and the high-$T_{\rm c}$ superconducting cuprates. 
A. Narduzzo, M. S. Grbi\'c, M. Po\v{z}ek, A. Dul\v{c}i\'c, D. Paar, A.   Kondrat, C. Hess, I. Hellmann, R. Klingeler, J. Wer...