Melting and solidification of Y1-xYbxBa2Cu3Oy: Influences of Yb doping andoxygen partial pressure

A comparative study was undertaken into the calcination conditions for the solid-state synthesis of pure Y1-xYDxBa2CU3O7-delta (X=0, 0.25, 0.5, 0.75, 1.0), the starting materials being Y2O3, Yb2O3, BaCO3 and CuO. It was found that the calcination time should go up and the sintering temperature shoul d lower, when the average rare earth ionic radius decreases. Moreover, the melting and the solidification temperatures of Y1-xYbxBa2Cu3Oy rise with de creasing Yb doping and increasing oxygen partial pressure, but depend only weakly on the particle size distribution. These deductions will be importan t to the fabrication of large-grain (Y,Y-b)BaCuO.