Orthorhombic to tetragonal transition and appearance of superconductivity in Nd{sub 0.7}Pr{sub 0.3}Ba{sub 2{minus}k}Sr{sub k}Cu{sub 3}O{sub 6+z} (0{<=}k{<=}1)

Journal Article · Wed Nov 01 00:00:00 EST 1995 · Materials Research Bulletin

DOI:https://doi.org/10.1016/0025-5408(95)00134-4· OSTI ID:137040

Das, A ^[1]; Suryanarayanan, R ^[2]

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1. CNRS, Meudon (France). Lab. de Physique des Solides de Bellevue
2. Univ. de Paris Sud, Orsay (France). Lab. de Chimie des Solides

Preparation, X-ray diffraction and ac susceptibility of Nd{sub 0.7}Pr{sub 0.3}Ba{sub 2{minus}k}Sr{sub k}Cu{sub 3}O{sub 6+z} (0 {<=} k {<=} 1) are reported. An orthorhombic to tetragonal transition was observed for k {>=} 0.75. Superconductivity occurred only for k{>=}0.25. When the samples were heated in argon prior to oxygen annealing both the orthorhombicity (for 0 {<=} k {<=} 0.75) and {Tc} increased (by 10 K for k = 1). Though a weakening of Pr-f hybridization with Cu-O bands due to Sr substitution may explain the data, a detailed knowledge of oxygen defect chemistry will be required to understand the behavior of Pr in LnBa{sub 2}Cu{sub 3}O{sub 6+z} (Ln = rare earths).

• OSTI ID: 137040
• Journal Information: Materials Research Bulletin, Vol. 30, Issue 11; Other Information: PBD: Nov 1995
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
NEODYMIUM OXIDES
SUPERCONDUCTIVITY
CRYSTAL-PHASE TRANSFORMATIONS
PRASEODYMIUM OXIDES
BARIUM OXIDES
STRONTIUM OXIDES
COPPER OXIDES
MAGNETIC SUSCEPTIBILITY
TRANSITION TEMPERATURE
EXPERIMENTAL DATA