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 YBa 2 Cu 3 O y composite with the additions of 40 mol% Y 2 BaCuO 5 , 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.

Novel seed for batch cold seeding production of GdBaCuO bulks

“…However, a lattice mismatch between MgO and LRE-123 is rather large and sometimes inhibits epitaxial growth. The control of the growth orientation with MgO seeds has been studied for various undercooling regimes with small samples [13]. Recently, mixed NEG-123 bulk pellets doped by a tiny amount of Zn have been shown to grow in excellent quality from MgO seed crystals.…”

Peritectic melting of thin films, superheating and applications in growth of REBCO superconductors

“…Cai et al first used highly c-oriented NdBCO/MgO thin films in cold-seeding melt-growth of low-T p materials, i.e., YBCO/ Ag bulks [104,105]. Single domain growth with a relationship of YBCOh1 0 0i bulk //NdBCOh1 0 0i film was obtained, indicating the possibility of applying film-seed in melt growth.…”

Superconducting and Mechanical Properties of RE-Ba-Cu-O/Ag Bulk Superconductors

“…While the isothermal solidification growth process provides us with the opportunity to obtain homogeneous composition, good electromagnetic and mechanical properties as well as the feasibility of batch production, it requires a challenge to control spontaneous nucleation and multiple growths. Concerning seeding techniques, a high-efficiency, practical seeding [6]. We have applied the seeding technique to investigate processing and properties of Ag-added YBaCuO and SmBaCuO textured bulk superconductors for stable production of large single-domain bulks [6], [7].…”

“…Concerning seeding techniques, a high-efficiency, practical seeding [6]. We have applied the seeding technique to investigate processing and properties of Ag-added YBaCuO and SmBaCuO textured bulk superconductors for stable production of large single-domain bulks [6], [7]. Table I shows the advantages of Sm123 superconducting bulks prepared by the melt process.…”

“…The precursor pellets were uniaxially pressed to 20 to 50 mm in diameter and 10 mm in thickness. The c-axis oriented Nd123/MgO thin film was employed as a cold seeding material [6].…”