View EntryDate of entry : 08/11/2010


X-ray analysis of the incommensurate modulation in the 2:2:1:2 Bi-Sr-Ca-Cu-O
superconductor including the oxigen atoms.

Gao, Y.; Lee, P.; Petricek, V.; Coppens, P. Phys. Rev. B 42 387 - 392 (1990)

[ B-IncStrDB ID: 252ECbetq ]
 
Submitted by : System [B-IncStrDB]CIF File

Bi-Sr-Ca-Cu-O_MOD

Chemical Properties

Structural Formula Sum: Bi2.14 Ca0.75 Cu2 O8 Sr1.91   [Help]
Weight: 899.7 Daltons  [Help]

Crystallographic Properties

Exp. Crystal Type of Struc.: mod   [Help]
a: 5.408(1) Å  [Help]
b: 5.413(1) Å  [Help]
c: 30.871(5) Å  [Help]
α: 90 °  [Help]
β: 90 °  [Help]
γ: 90 °  [Help]
Volume: 903.7(3) Å3  [Help]
Crystal System: orthorhombic   [Help]
Space Group Name (H-M): A 2 a a   [Help]
Space Group Name: X2aa(α00)000   [Help]
Number of Formula Units: 4   [Help]

  •  Additional Crystal Information   

Experimental Data

Absorption_coeff_μ: 60.618 &mm;  [Help]
Radiation Type: Mo Kα   [Help]
Radiation Wavelength: 0.71069 Å  [Help]
Radiation source: X-ray tube   [Help]
Max Order of Satellite Reflections: 2   [Help]

  •  Additional Experimental Information   

Refinement Properties

Modulation function desc.:
Displacive modulation for Bi, Sr, Cu, Ca, O(1), O(2) and O(3) sites:Fourier
series. Up to 2nd-order harmonics. Modulation of O(4) atoms described by
a sawtooth function. Modulation of temperature factors for Bi sites:Fourier
series. Up to 2nd-order harmonics.
  [Help]

Structure factors calc. details: Bessel functions   [Help]
# of observed reflections: 658   [Help]
Residual factor for the observed reflns.: 0.072   [Help]
Refinement Special Details:
WARNING: The published displacement parameters have been converted to relative
units. The calculated standard uncertainties (s.u.) have been based uniquely on
the published ones without considering the s.u. of any other quantity involved
in such conversion.
  [Help]

  •  Additional Refinement Information   

Diffraction Data

Radiation source: X-ray tube   [Help]
Radiation Wavelength: 0.71069 Å  [Help]

  •  Additional Diffraction Data Information   


  •  Reference Structure Information   

  •  Modulation Parameters (Tables)   

  •  Refinement Summary   

  •  Modulation Parameters (Atom Sites Summary)