A new Hg based oxycarbonate superconductor HgBa2Sr2Cu2O6+δ(CO3) has been found by resistivity and magnetization measurements. The superconductivity has been observed at 66 K by magnetization measurement. The electron-diffraction and HRTEM studies show that the crystal structure basically consisted of [HgBa2O2+δ] and [Sr2CO3] block layers and has a tetragonal unit cell, with a=3.88 A ̊, c=16.94 A ̊, with an orthorhombic superstructure, with A≈4.5√2a=24.71 A ̊,B≈√2a=5.49 A ̊, C=c=16.94 A ̊, due to the three times periodic replacements of a CO3 block for HgOδ in the same c-planes or to a c/2 shift approximately at intervals of three tetragonal cells along the (110) direction. The crystal structure of this compound is described by the following combination: [(Hg0.5C0.5)(Ba,Sr)2O2.5+δ]+CuO2+[(Ba,Sr)2(C0.5Hg0.5)O2.5+δ]+CuO2.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering