The effects of SnO2 addition on the growth of Y2BaCuO5 and YBa2Cu3O7- delta phases in the Y-Ba-Cu-O system

Abstract

With YBa2Cu3Sn0.1O7- delta and Y2BaCu1.8Sn0.1O5+ delta specimens, the effect of SnO2 addition on the 211 phase growth is investigated. The addition of SnO2 is considered to make the nucleation of the 211 phase occur favourably. In order to study the effect of SnO2 addition on 123 phase growth in the Y-Ba-Cu-O system, a 0.1 SnO2-added 123+Sn compact is coupled with the SnO2-free 123 compact(s). The 123 phase forms in the surface region of the 123+0.1 Sn compact and grows toward the interior of this compact and toward the SnO2-free 123 compact(s). It is considered that the addition of SnO2 and faster cooling in the surface region than in the inner region of the sample make the nucleation of the 123 phase occur favourably in the surface region of the 123+0.1 Sn compact.