Preparation, structure, and peritectic transition of RBa{sub 1.5}Sr{sub 0.5}Cu{sub 3}O{sub y} (R = La, Nd, Sm, Eu, Gd, Dy, Ho, and Y) superconductors

Journal Article · Sat Aug 01 04:00:00 EDT 1998 · Materials Research Bulletin

DOI:https://doi.org/10.1016/S0025-5408(98)00092-0· OSTI ID:638343

Lin, M Y; Huang, J T; Kao, H C.I.; Wang, C M ^[1]

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1. Tamkang Univ., Tamsui (Taiwan, Province of China). Dept. of Chemistry

A series of single-phase RBa{sub 1.5}Sr{sub 0.5}Cu{sub 3}O{sub y} (T = La, Nd, Sm, Eu, Gd, Dy, Ho, and Y) compounds with a triple-perovskite unit cell has been prepared by solid-state reaction method. Samples with a larger radius of the R ion (R = La and Nd) are tetragonal, whereas those with a smaller radius of the R ion (R = Sm, Eu, Gd, Dy, Ho, and Y) are orthorhombic. Unit-cell parameters of RBa{sub 1.5}Sr{sub 0.5}Cu{sub 3}O{sub y} decrease monotonically with a decrease of the radius of the R ion. A maximum at R = Nd, Sm, and Eu is found in the peritectic transition temperature (t{sub p}), the amount of oxygen loss ({Delta}w) in this transition, and the enthalpy of fusion ({Delta}H{sub f}), respectively. An increase in the {Delta}H{sub f} is correlated with increasing t{sub p} for the respective orthorhombic and tetragonal phases of RBa{sub 1.5}Sr{sub 0.5}Cu{sub 3}O{sub y} compounds. {Tc} of the title compounds gradually increased from 52 to 86 K with a decrease in the radius of the R ion.

• OSTI ID: 638343
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 8 Vol. 33; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
CHEMICAL PREPARATION
COPPER OXIDES
CRYSTAL STRUCTURE
ORTHORHOMBIC LATTICES
RARE EARTHS
STRONTIUM OXIDES
TETRAGONAL LATTICES
THERMODYNAMIC PROPERTIES
YTTRIUM OXIDES