Pr and Cu magnetism in (Pr{sub 1.5}Ce{sub 0.5})Sr{sub 2}Cu{sub 2}MO{sub 10{minus}{delta}} (M=Nb, Ta): Correlations with a suppression of superconductivity

Journal Article · Sat Feb 01 00:00:00 EST 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.55.3297· OSTI ID:450380

Goodwin, T J; Shelton, R N ^[1]; Radousky, H B ^[2]; Rosov, N; Lynn, J W ^[3]

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1. Department of Physics, University of California, Davis, California 95616 (United States)
2. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
3. Reactor Radiation Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

The magnetic properties of nonsuperconducting (Pr{sub 1.5}Ce{sub 0.5})Sr{sub 2}Cu{sub 2}MO{sub 10{minus}{delta}} with M=Nb, Ta are characterized with dc magnetization, specific-heat, and neutron-diffraction experiments. Data for (Pr{sub 1.5}Ce{sub 0.5})Sr{sub 2}Cu{sub 2}NbO{sub 10{minus}{delta}} reveal complex Cu magnetism marked by antiferromagnetic order below 200 K, spin structure transitions at 130 and 57 K, both collinear and noncollinear antiferromagnetic spin structures, and weak ferromagnetic behavior below 130 K. The data also indicate an anomalous ordering of the Pr spins near 10 K, a large linear contribution to the low-temperature specific heat, and a Pr 4f crystal-field ground state similar to that found in PrBa{sub 2}Cu{sub 3}O{sub 7}. Furthermore, there is evidence that the weak ferromagnetic behavior couples to the Pr ordering near 10 K. Identical Pr magnetism and similar Cu magnetism are found in (Pr{sub 1.5}Ce{sub 0.5})Sr{sub 2}Cu{sub 2}TaO{sub 10{minus}{delta}}, deoxygenated (Pr{sub 1.5}Ce{sub 0.5})Sr{sub 2}Cu{sub 2}NbO{sub 10{minus}{delta}}, and deoxygenated (Pr{sub 1.5}Ce{sub 0.5})Sr{sub 2}Cu{sub 2}TaO{sub 10{minus}{delta}}. These results indicate that superconductivity is suppressed in these compounds in the same phenomenological manner as in PrBa{sub 2}Cu{sub 3}O{sub 7}. We interpret this as evidence that superconductivity is suppressed by the same mechanism in both structures and propose that a general correlation exists between anomalous Pr magnetism and a lack of superconductivity in these Pr-based high-T{sub C} cuprates. The significance of these results and analyses to understanding and modeling the suppression of superconductivity by Pr in high-T{sub C} cuprates is discussed. {copyright} {ital 1997} {ital The American Physical Society}

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 450380
• Journal Information: Physical Review, B: Condensed Matter, Vol. 55, Issue 5; Other Information: PBD: Feb 1997
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
SUPERCONDUCTIVITY
MAGNETIC PROPERTIES
PRASEODYMIUM COMPOUNDS
CERIUM COMPOUNDS
STRONTIUM COMPOUNDS
COPPER COMPOUNDS
NIOBIUM COMPOUNDS
TANTALUM COMPOUNDS
OXYGEN COMPOUNDS
MAGNETIC MOMENTS
PRASEODYMIUM OXIDES
CERIUM OXIDES
STRONTIUM OXIDES
COPPER OXIDES
NIOBIUM OXIDES
TANTALUM OXIDES
SPECIFIC HEAT
NEUTRON DIFFRACTION