YBa_2Cu_3 O_(7-x)(YBCO) is one of thesuperconducting oxides with transition tem-perature above 90K.It has a orthorhombic crystal structrure ofa layered-perovsk
The phase boundary,of α_2 precipitation at 600℃ in Ti-AI-La ternary system has been de-termined by TEM examination,which shows three kinds of phase regions,n