Optimization of a Novel Melt-Growth Heat Treatment of YbBa2Cu3O7-δ /Ag Tapes

A novel melt-growth heat treatment of YbBa ₂ Cu ₃ O _7-δ (Yb123) powder in Ag-sheathed tape has been established as a necessary first step to form aligned Yb123 grains in a powder-in-tube (PIT) conductor. The heat treatment parameters including the rate at which the atmosphere was changed from Ar to pure O 2, the heat treatment temperature, and the time during which the melt transformed back to Yb123 were investigated to find the optimum parameters for reforming Yb123 in Ag-sheathed tape. The Yb123 purity after being reformed is insensitive to the rate at which the atmosphere was changed. The optimized parameters are 910 °C for 48 h to reform Yb123.