A new homologous series of oxycarbonate superconductors Sr2(Ca,Sr)n-1Cun(CO3)1-χ(BO3)χOy (n=1, 2 and 3) prepared under high pressure have been found by resistivity and magnetization measurements. X-ray powder diffraction and HRTEM studies show that these phases have tetragonal structures with a=3.86 A ̊ and c=7.40 A ̊ for n=1, a=3.86 A ̊ and c=10.62 A ̊ for n=2, and a=3.87 A ̊ and c=13.98 A ̊ for n=3. Resistivity and magnetization measurements revealed that superconducting transition temperatures were 50, 105 and 115 K for n=1-3, respectively. These Tc's are higher than those of the structurally related analogous TlBa2Can-1CunO2n+3 at 100 and 110 K (n=2 and 3).
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering