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The fluorite-related cubic structure of yttria-stabilized zirconia, Zr0.758Y0.242O1.879, has been studied by single-crystal X-ray diffraction using synchrotron radiation and by EXAFS. Two diffraction data sets obtained at X-ray energies of 512 and 10 eV below the Y K edge revealed that in the average structure Zr atoms are displaced from the origin of the space group Fm3m along <111> by 0.19 Å, while Y atoms reside at the origin. Approximately 48% of the O atoms occupy the ideal position in the fluorite-type structure, while 43% of O atoms are displaced from the ideal position along <001> by 0.31 Å. The remaining 9% of O atoms are presumably sited at interstitial positions. Local structures around Zr and Y are investigated by combining the results of single-crystal X-ray diffraction and EXAFS studies.

Supporting information

cif

Crystallographic Information File (CIF)
Contains datablocks ysz_f, ysz_n, global

hkl

Structure factor file (CIF format)
Contains datablock ysz_n

hkl

Structure factor file (CIF format)
Contains datablocks global, ysz_f

Computing details top

For both compounds, data reduction: xtal_DIFDAT_ABSORB_SORTRF_ADDREF (Hall et al., 1995); program(s) used to solve structure: Xtal (Hall et al., 1995); program(s) used to refine structure: xtal_CRYLSQ (Hall et al., 1995); molecular graphics: Xtal (Hall et al., 1995). Software used to prepare material for publication: xtal_BONDLA_CIFIO (Hall et al., 1995) for ysz_f; xtal_CIFIO (Hall et al., 1995) for ysz_n.

Figures top
[Figure 1]
[Figure 2]
[Figure 3]
[Figure 4]
(ysz_f) Yttrium Zirconium Oxide top
Crystal data top
Zr.758Y.242O1.879F(000) = 219.16
Mr = 120.73Dx = 5.855 Mg m3
Cubic, Fm3mSynchrotron radiations radiation, λ = 0.7502 Å
Hall symbol: -F 4 2 3µ = 7.71 mm1
a = 5.15463 (5) ÅT = 293 K
V = 136.96 (1) Å3, transparent colourless
Z = 40.02 (1) mm (radius)
Data collection top
Horizontal-type four-circle
diffractometer
Rint = 0.018
Si(111) double crystal monochromatorθmax = 68.7°, θmin = 7.2°
continuous θ/2θ scanh = 1212
Absorption correction: for a sphere
?
k = 1212
Tmin = 0.818, Tmax = 0.823l = 1212
2277 measured reflections6 standard reflections every 100 reflections
83 independent reflections intensity decay: none
83 reflections with refl observed if F > 3.000 σ(F )
Refinement top
Refinement on F0 constraints
Least-squares matrix: fullσ
R[F2 > 2σ(F2)] = 0.005
wR(F2) = 0.009Δρmax = 0.28 e Å3
S = 6.18Δρmin = 0.34 e Å3
83 reflectionsExtinction correction: Becker & Coppens (1974a,b)
10 parametersExtinction coefficient: 1972 (522)
0 restraints
Crystal data top
Zr.758Y.242O1.879Z = 4
Mr = 120.73Synchrotron radiations radiation, λ = 0.7502 Å
Cubic, Fm3mµ = 7.71 mm1
a = 5.15463 (5) ÅT = 293 K
V = 136.96 (1) Å30.02 (1) mm (radius)
Data collection top
Horizontal-type four-circle
diffractometer
83 reflections with refl observed if F > 3.000 σ(F )
Absorption correction: for a sphere
?
Rint = 0.018
Tmin = 0.818, Tmax = 0.8236 standard reflections every 100 reflections
2277 measured reflections intensity decay: none
83 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.00510 parameters
wR(F2) = 0.0090 restraints
S = 6.18Δρmax = 0.28 e Å3
83 reflectionsΔρmin = 0.34 e Å3
Special details top

Refinement. Sfls F σ weight full matrix

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Zr0.02103 (9)0.02103 (9)0.02103 (9)0.00862 (17)*
Y0.000000.000000.000000.00591 (12)*
O10.250000.250000.250000.016 (2)*
O20.311 (5)0.250000.250000.0144 (10)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
???????
Bond lengths (Å) top
Zr—O12.0442 (5)Zr—O2vi2.126 (13)
Zr—O22.240 (16)Zr—O2vii2.158 (10)
Zr—O1i2.3014 (5)Zr—O2viii1.881 (11)
Zr—O2i2.477 (15)Zr—O2ix2.254 (12)
Zr—O2ii2.504 (17)Zr—O2x1.990 (13)
Zr—O1iii2.1766 (5)Zr—O2xi2.024 (11)
Zr—O2iii2.361 (16)Y—O12.2320 (1)
Zr—O2iv2.390 (18)Y—O22.426 (16)
Zr—O1v2.4198 (5)Y—O2viii2.067 (12)
Zr—O2v2.613 (16)
Symmetry codes: (i) x, y, z; (ii) x, y, z; (iii) y, x, z; (iv) y, x, z; (v) y, x, z; (vi) x1/2, y, z1/2; (vii) x+1/2, y, z1/2; (viii) x+1/2, y+1/2, z; (ix) y, x1/2, z1/2; (x) y+1/2, x1/2, z; (xi) z, y+1/2, x+1/2.
(ysz_n) Yttrium Zirconium Oxide top
Crystal data top
Zr.758Y.242O1.879Dx = 5.855 Mg m3
Mr = 120.73Synchrotron radiation radiation, λ = 0.7281 Å
Cubic, Fm3mCell parameters from 25 reflections
Hall symbol: -F 4 2 3θ = 34.4–43.8°
a = 5.15463 (5) ŵ = 7.12 mm1
V = 136.96 (1) Å3T = 293 K
Z = 4, transparent colourless
F(000) = 219.160.02 (1) mm (radius)
Data collection top
Horizontal-type four-circle
diffractometer
Rint = 0.018
Si(111) double crystal monochromatorθmax = 69.8°, θmin = 7.0°
continuous θ/2θ scanh = 1313
Absorption correction: for a sphere
?
k = 1313
Tmin = 0.831, Tmax = 0.835l = 812
1258 measured reflections6 standard reflections every 100 reflections
90 independent reflections intensity decay: none
90 reflections with refl observed if F > 3.000 σ(F )
Refinement top
Refinement on F0 constraints
Least-squares matrix: fullσ
R[F2 > 2σ(F2)] = 0.009(Δ/σ)max < 0.001
wR(F2) = 0.013Δρmax = 0.29 e Å3
S = 5.88Δρmin = 0.46 e Å3
90 reflectionsExtinction correction: Becker & Coppens (1974a,b)
10 parametersExtinction coefficient: 1977 (215)
0 restraints
Crystal data top
Zr.758Y.242O1.879Z = 4
Mr = 120.73Synchrotron radiation radiation, λ = 0.7281 Å
Cubic, Fm3mµ = 7.12 mm1
a = 5.15463 (5) ÅT = 293 K
V = 136.96 (1) Å30.02 (1) mm (radius)
Data collection top
Horizontal-type four-circle
diffractometer
90 reflections with refl observed if F > 3.000 σ(F )
Absorption correction: for a sphere
?
Rint = 0.018
Tmin = 0.831, Tmax = 0.8356 standard reflections every 100 reflections
1258 measured reflections intensity decay: none
90 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.00910 parameters
wR(F2) = 0.0130 restraints
S = 5.88Δρmax = 0.29 e Å3
90 reflectionsΔρmin = 0.46 e Å3
Special details top

Refinement. Sfls F σ weight full matrix

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Y0.000000.000000.000000.00056 (16)*
Zr0.02186 (12)0.02186 (12)0.02186 (12)0.0100 (2)*
O10.250000.250000.250000.019 (2)*
O20.317 (6)0.250000.250000.014 (2)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
???????

Experimental details

(ysz_f)(ysz_n)
Crystal data
Chemical formulaZr.758Y.242O1.879Zr.758Y.242O1.879
Mr120.73120.73
Crystal system, space groupCubic, Fm3mCubic, Fm3m
Temperature (K)293293
a (Å)5.15463 (5) 5.15463 (5)
V3)136.96 (1)136.96 (1)
Z44
Radiation typeSynchrotrons, λ = 0.7502 ÅSynchrotron, λ = 0.7281 Å
µ (mm1)7.717.12
Crystal size (mm)0.02 (1) (radius)0.02 (1) (radius)
Data collection
DiffractometerHorizontal-type four-circle
diffractometer
Horizontal-type four-circle
diffractometer
Absorption correctionFor a sphereFor a sphere
Tmin, Tmax0.818, 0.8230.831, 0.835
No. of measured, independent and
observed [refl observed if F > 3.000 σ(F )] reflections
2277, 83, 83 1258, 90, 90
Rint0.0180.018
(sin θ/λ)max1)1.2421.289
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.005, 0.009, 6.18 0.009, 0.013, 5.88
No. of reflections8390
No. of parameters1010
Δρmax, Δρmin (e Å3)0.28, 0.340.29, 0.46

Computer programs: xtal_DIFDAT_ABSORB_SORTRF_ADDREF (Hall et al., 1995), Xtal (Hall et al., 1995), xtal_CRYLSQ (Hall et al., 1995), xtal_BONDLA_CIFIO (Hall et al., 1995), xtal_CIFIO (Hall et al., 1995).

Possible bond distances calculated from the average structure of Y-CSZ top
CationType ofDistance(Å) withSymmetry operationNo. of bonds with
O atomesd in parentheses(representative)same distance/number of
possible bonds for the
the same type of O atoms
Y at originO12.23202 (1)x,y,z8/8
O22.067 (12)1/2-x,1/2-y,z24/48
O22.426 (16)x,y,z24/48
Zr at (x,x,x)O12.0443 (5)x,y,z1/8
x=0.02103O12.1766 (5)-y,x,z3/8
O12.3014 (5)x,-y,-z3/8
O12.4198 (5)-y,-x,-z1/8
O21.881 (11)1/2-x,-1/2-y,z3/48
O21.990 (13)1/2-y,1/2+x,z3/48
O22.024 (11)-z,1/2-y,1/2-x6/48
O22.126 (13)-1/2+x,y,-1/2+z6/48
O22.158 (10)1/2-x,-y,-1/2+z3/48
O22.240 (16)x,y,z3/48
O22.254 (12)-y,-1/2+x,-1/2+z3/48
O22.361 (16)-y,x,-z6/48
O22.390 (18)y,-x,z3/48
O22.477 (15)x,-y,-z3/48
O22.504 (17)-x,-y,z6/48
O22.613 (16)-y,-x,-z3/48
Table 4. EXAFS Results. N: Coordination number, R: interatomic distance (Å), σ: Debye-Waller factors (Å2) top
Centre atomNRσ
Y5.9 (3)2.32 (1)0.064 (3)
Zr7.0 (3)2.13 (1)0.072 (3)
 
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