Abstract
Microwave power (Pm) dependence of microwave absorption (MA) was investigated on Bi2Sr2CaCu2Ox crystals at liquid nitrogen temperature. At low Pm of 0.1 mW, MA spectrum shows only a sharp first peak near zero magnetic fields (Ha), which corresponds to Meissner phase, for Ha∥c-axis. MA spectrum shows a dip and a broad second peak when Pm is increased. These dip and broad peak reflect reentrant liquid phase and solid phase. The broad peak shifts to lower fields with increasing Pm. The real sample temperature is raised by 4 K with increasing Pm to 50 mW.