Microwave absorption studies of Y-Ba-Cu-O

We have measured the magnetic field dependence of the microwave absorption of bulk ceramic Y₁{Ba}₂Cu₃{O}ₓ$ as a function of temperature. Below the superconducting transition temperature, the microwave absorption increases with increasing magnetic-flux penetration into the sample, and the absorption exhibits considerable hysteresis resulting from hysteresis in sample magnetization. Also, when the applied magnetic field is removed there is a remanant absorption due to the remanant sample magnetization.