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Journal of Low Temperature Physics

, Volume 117, Issue 3–4, pp 849–853 | Cite as

A Study of Structure, Electric and Magnetic Properties of the New Layered Cobalt Oxides Sr2Y1-xCa x Co2O7-z

  • K. Yamaura
  • Q. Huang
  • R.W. Erwin
  • J.W. Lynn
  • R.J. Cava
Article

Abstract

The crystal structure of Sr 2 Y 0.8 Ca 0.2 Co 2 O 6 is orthorhombic below 270 K (Immm, a = 3.84029(7) Å, b = 3.80691(6) Å and c = 19.4980(3) Å at 20 K), transformed from tetragonal (I4/mmm, a = 3.82765(6) Å and c = 19.5795(3) Å) at 295 K. The crystal structure distortion is accompanied by an anomalous temperature dependence of the degree of buckling of the CoO 2 plane and is correlated with the development of anisotropic antiferromagnetic ordering of magnetic moments (2.93(2) μ B per Co at 20 K). A magnetically glassy state below about 35 K and variable range hopping conduction below about 64 K for \(\begin{gathered} Sr_2 Y_{1 - x} Ca_x Co^{3.4 + } _2 O_{7 - z} (0.2 \leqslant x \leqslant 0.5,0.21 \leqslant z \leqslant 0.38) \hfill \\ \hfill \\ \end{gathered} \) were found by magnetic susceptibility and electrical resistivity measurements.

Keywords

Oxide Crystal Structure Cobalt Magnetic Property Magnetic Susceptibility 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Plenum Publishing Corporation 1999

Authors and Affiliations

  • K. Yamaura
    • 1
  • Q. Huang
    • 2
    • 3
  • R.W. Erwin
    • 2
  • J.W. Lynn
    • 2
  • R.J. Cava
    • 1
  1. 1.Department of Chemistry andPrinceton Materials Institute, Princeton UniversityPrincetonUSA
  2. 2.NIST Center for Neutron Research, National Institute of Standards and TechnologyGaithersburgUSA
  3. 3.Department of Materials and Nuclear EngineeringUniversity of MarylandCollege ParkUSA

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