Numerical Simulation of Peritectic Growth of Faceted 123 Crystals in Superconductive YBCO Oxides

• Mori Nobuyuki

  Department of Materials Physics and Chemistry, Graduate School of Engineering, Kyushu University

• Ogi Keisaku

  Department of Materials Process Engineering, Graduate School of Engineering, Kyushu University

Bibliographic Information

Other Title

• 超伝導YBCO酸化物におけるファセット型123結晶の包晶凝固シミュレーション
• チョウデンドウ YBCO サンカブツ ニ オケル ファセットガタ 123 ケッショウ ノ ホウショウギョウコ シミュレーション

Abstract

To clarify the solidification mechanism of the faceted 123(YBa₂Cu₃O_7−x) crystals from liquid+primary 211(Y₂BaCuO₅) phases of the superconductive Y-Ba-Cu-oxides (YBCO), new 2-dimensional numerical simulation method of the growth process of the faceted peritectic crystal is proposed and appreciated with the experimental results. The basic model of peritectic solidification of the 123 phase consists of three sequential primitive processes: (a) growth of faceted peritectic crystals, (b) melting of primary particles in the liquid, and (c) solute diffusion in the liquid. Two-dimensional numerical calculations for peritectic growth of the faceted 123 phase with solute diffusion in the liquid are carried out by the explicit control volume finite difference method (FDM) to calculate distribution of 211 particles in the 123 phase and solute distribution in the liquid from the initial distribution of 211 particles in the liquid. The normal growth rate (R) of a facet plane is given by the following relation, which suggests the screw dislocation mechanism: R=a_g·ΔT_k², where a_g is a kinetic growth constant, and ΔT_k is the kinetic undercooling on the faceted interface. The melting rate of superheated 211-particles in the liquid is also assumed to be given by the above equation with a kinetic melting constant (a_m). The effects of the ratio (a_g⁄a_m), the diffusion coefficient in the bulk liquid, the interface energy of 211 particles, and the local undercooling caused by non-uniform distribution of 211 particles on the growth process are examined in the calculations. The distributions of residual 211 particles and liquid pools in the faceted 123 crystals are calculated form the experimentally obtained log-normal distributions of 211 particles in the liquid of YBCO quenched during unidirectional solidification, and the calculated distributions agree well with the experimental results.

Journal

• Journal of the Japan Institute of Metals and Materials

  Journal of the Japan Institute of Metals and Materials 62 (12), 1109-1116, 1998

  The Japan Institute of Metals and Materials

Keywords

• superconductor
• numerical simulation
• YBa<SUB>2</SUB>Cu<SUB>3</SUB>O<SUB>7−<I>x</I></SUB>
• peritectic, oxide
• facet
• solidification
• yttrium-barium-copper-oxides; YBCO
• Y<SUB>2</SUB>BaCuO<SUB>5</SUB>

Details

• CRID: 1390001206491534976
• NII Article ID: 130007342144
• NII Article ID: 10002548104
• NII Book ID: AN00187860
• DOI: 10.2320/jinstmet1952.62.12_1109
• ISSN: 18806880
• ISSN: 24337501
• ISSN: 00214876
• ISSN: http://id.crossref.org/issn/00214426
• NDL BIB ID: 971208
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I971208
• Web Site: https://www.jstage.jst.go.jp/article/jinstmet1952/62/12/62_12_1109/_pdf
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed