HIGH Tc SUPERCONDUCTIVITY IN LnBa₂Cu₃O_7-y(Ln=Yb, Er ) SINGLE CRYSTAL WITH LARGE SIZE

Two kinds of single crystal YbBa₂Cu₃O_7-y and ErBa₂Cu₃O_7-y have been grown by the fluxed method. They are orthorhombic structure with space group Pmmm, cell parameters are a=3.88Å, b=3.82Å, c=11.68Å and their typical size are 3x2x2mm³. The superconducting critical temperature is over 90K. Their superconductivity is discussed.