Microwave surface resistance of HgBa2CaCu2O6+delta thin films

Microwave surface resistance (R-s) has been measured on c-axis-oriented sup erconducting HgBa2CaCu2O6+delta (Hg-1212) films. A cavity perturbation meth od was employed using a high-Q Nb cavity cooled at 4.2 K. For the best film , an R-s as low as similar to 0.3 m Omega was observed at 10 GHz up to simi lar to 120 K on Hg-1212 films that have smooth surface morphology and high critical current density near 2 MA/cm(2) at 100 K and self-field. This resu lt suggests that Hg-1212 films are very promising for microwave application s above 100 K. (C) 2000 American Institute of Physics. [S0003-6951(00)01012 -3].