Control of YBCO growth at the compact substrate interface by bottom seeding and Yb2O3 coating in seeded melt-growth processed YBCO oxides using a MgOsubstrate
Cj. Kim et al., Control of YBCO growth at the compact substrate interface by bottom seeding and Yb2O3 coating in seeded melt-growth processed YBCO oxides using a MgOsubstrate, PHYSICA C, 315(3-4), 1999, pp. 263-270
Effects of a seeding technique and surface coating with Yb2O3 powder on the
growth of YBCO grains at the compact/substrate (a MgO single crystal) inte
rfaces were studied. Zn a single top-seeded sample without Yb2O3 coating, s
everal YBCO grains nucleated at the compact/substrate interface. In a doubl
e seeded (top and bottom) sample without Yb2O3 coating, YBCO grains nucleat
ed both at the bottom seed and MgO substrate competitively, resulting in pa
rtial texturing of YBCO grains at the bottom. Applying a double seeding tec
hnique with Yb2O3 coating both at the compact/MgO interface and sample surf
aces inhibited the undesirable subsidiary YBCO nucleation at both the surfa
ces and interfaces, resulting in the growth of a single YBCO grain. As a re
sult of the suppression of subsidiary Y123 nucleation, a magnetic levitatio
n force of the sample bottom was improved significantly. (C) 1999 Elsevier
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