Effects of Nd123/MgO Thin Film and MgO Single-crystal Seeds in Isothermal Solidification of YBaCuO/Ag

Abstract

The seeding effects of (001) Nd123/MgO thin films and MgO single crystals were studied in isothermal solidification of YBa2Cu3Oy composite with the additions of 40 mol% Y2BaCuO5, 10 wt% Ag, and 0.5 wt% Pt. Seeding with the Nd123/MgO thin film resulted in single-domain growth of Y123 crystal with a stable growth along the “100”?direction, while seeding with MgO single crystal produced multidomain growth in which the dominant growth facet is rotated 45° about (100) plane of MgO. Multidomain growth in MgO seeded sample was suppressed by decreasing undercooling degree. The effects of undercooling degree and seed size on multidomain growth are discussed in view of classical nucleation and growth theory.