High-resolution electron microscopy studies of high-pressure synthesized mercury-based superconductor

Studies of high-pressure synthesized Hg-Ba-Ca-Cu-O superconductor by electron diffraction and high-resolution electron microscopy are reported. The results of electron diffraction indicate that two superconducting phases 1212 and 1223 exist in the sample and their cell parameters are a=b=3.8 Angstrom, c=12.7 Angstrom and a=b=3.8 Angstrom, c=15.8 Angstrom, respectively. High-resolution electron micrographs were taken from the two phases Hg-1212 and Hg-1223 and from the region of the intergrowth of the two phases. The relation between the structure and superconducting transitional temperature T-c is discussed.