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The crystal structure of orthorhombic yttrium calcium barium nickel pentaoxide, Y1.90Ca0.10BaNiO5, a charge-doped quasi-one-dimensional nickel oxide, has been determined from X-ray single-crystal data at room temperature. Ca2+ ions replace at random the Y3+ ions within the Immm crystal structure of the undoped compound, Y2BaNiO5.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801011667/br6025sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536801011667/br6025Isup2.hkl
Contains datablock I

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](Ni-O) = 0.001 Å
  • Disorder in main residue
  • R factor = 0.016
  • wR factor = 0.042
  • Data-to-parameter ratio = 18.6

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


Yellow Alert Alert Level C:
PLAT_301 Alert C Main Residue Disorder ........................ 24.00 Perc. PLAT_302 Alert C Anion/Solvent Disorder ....................... 2.00 Perc.
0 Alert Level A = Potentially serious problem
0 Alert Level B = Potential problem
2 Alert Level C = Please check

Comment top

The crystal structure of the divalent nickel oxide Y2BaNiO5 was first determined from single-crystal diffraction data by Müller-Buschbaum & Schlüter (1990), Amador et al. (1990) and Buttrey et al. (1990). It has an orthorhombic crystal structure that contains infinite linear chains of flattened NiO6 octahedra sharing corners along the crystallographic a direction. The magnetic properties of this charge-transfer insulator are those of an antiferromagnetic chain compound with a Haldane spin gap (Darriet & Regnault, 1993). Hole doping in Y2BaNiO5, which is achieved by substituting Ca2+ for Y3+, has attracted considerable attention in recent years, arising from quite interesting electronic and physical properties and possible connections to high-temperature superconductivity (Di Tusa et al., 1994; Janod et al., 2001). X-ray and neutron-powder diffraction data for Y2 - xCaxBaNiO5 have been analysed using the Rietveld method (Massarotti et al., 1999) but, as far as we know, no single-crystal structure determination has been published so far.

In this work, we have analyzed a single-crystal of Y2 - xCaxBaNiO5, prepared by a flux method. The refinement of the single-crystal data confirms that Ca2+ ions replace at random the Y3+ ions within the Immm crystal structure of the undoped compound without any sign of superstructure, in agreement with the results of a previous electron diffraction study (Xu et al., 2001). The refinement of the Ca,Y occupancy factors leads to the composition x = 0.10 (1), in agreement with the value determined from our energy-dispersive X-ray elemental analysis, x = 0.11 (2). Atomic parameters (positions, ADP's and occupation ratio) are obtained here with s.u.'s much smaller than those reported from powder data (Massarotti et al., 1999). Moreover, the z coordinate of the Y/Ca site is very close to those reported for the undoped compound by Müller-Buschbaum & Schlüter (1990) and Amador et al. (1990), but significantly different from that obtained by Buttrey et al. (1990). Our study seems to highlight the unreliability of the refinement of Buttrey et al. (1990) concerning not only the lattice parameters, as already suggested by these authors, but also the z coordinate of the Y site.

We thus confirm that substitution of Y3+ by Ca2+ does not induce significant structural modification around the Y site. On the other hand, the Ni—O1 and Ni—O2 distances are found to decrease upon doping in spite of a bigger ionic radius for Ca2+, as suggested earlier (Massarotti et al., 1999). The shortening of both axial Ni—O1 and equatorial Ni—O2 distances is due to the effects of hole doping on the electronic structure close to the Fermi level (Lannuzel et al., 2001).

Experimental top

Single crystals of Y1.90Ca0.10BaNiO5 were prepared using a self-flux method, as described by Yokoo et al. (1995). We first synthetized a ceramic sample of the parent compound Y2BaNiO5 by solid-state reaction from a mixture of NiO, Y2O3 and BaCO3 in air. We then added this polycrystalline sample to a mixture of CaCO3, NiO and BaCO3, in a mole ratio of CaCO3:NiO:BaCO3:Y2O3 = 1.62:45:45:10. This mixture was then heated at 1723 K for 2 h in a Pt crucible, and slowly cooled (2 K h-1) to room temperature.

Computing details top

Data collection: CAD-4-PC Software (Enraf-Nonius, 1992); cell refinement: CAD-4-PC Software; data reduction: JANA2000 (Petrícek & Dusek, 2000); program(s) used to refine structure: JANA2000; molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: JANA2000.

Figures top
[Figure 1] Fig. 1. A view of the unit cell of Y1.90Ca0.10BaNiO5. Displacement ellipsoids are drawn here at the 97% probability level. Ni—O bonds of the central NiO6 octahedra and unit-cell edges are shown.
[Figure 2] Fig. 2. Schematic view of the crystallographic structure of Y1.90Ca0.10BaNiO5 highlighting the existence of linear chains of vertex-sharing NiO6 octahedra.
(I) top
Crystal data top
Y1.90Ca0.10BaNiO5Dx = 6.097 Mg m3
Mr = 449Mo Kα radiation, λ = 0.71069 Å
Orthorhombic, ImmmCell parameters from 25 reflections
a = 3.7527 (5) Åθ = 7.4–15.0°
b = 5.7581 (9) ŵ = 34.10 mm1
c = 11.313 (2) ÅT = 293 K
V = 244.46 (6) Å3Thick needle, black
Z = 20.16 × 0.02 × 0.02 mm
F(000) = 400
Data collection top
CAD-4
diffractometer
Rint = 0.035
ω scansθmax = 38.0°, θmin = 3.6°
Absorption correction: gaussian
(JANA2000; Petrícek & Dusek, 2000)
h = 66
Tmin = 0.420, Tmax = 0.511k = 99
2650 measured reflectionsl = 1919
409 independent reflections3 standard reflections every 60 min
387 reflections with I > 2σ(I) intensity decay: 0.8%
Refinement top
Refinement on F2Weighting scheme based on measured s.u.'s w = 1/[σ2(I) + 0.001024I2]
R[F2 > 2σ(F2)] = 0.016(Δ/σ)max = 0.003
wR(F2) = 0.042Δρmax = 1.07 e Å3
S = 1.00Δρmin = 1.64 e Å3
409 reflectionsExtinction correction: B-C type 1 Lorentzian isotropic
22 parametersExtinction coefficient: 0.45 (2)
Crystal data top
Y1.90Ca0.10BaNiO5V = 244.46 (6) Å3
Mr = 449Z = 2
Orthorhombic, ImmmMo Kα radiation
a = 3.7527 (5) ŵ = 34.10 mm1
b = 5.7581 (9) ÅT = 293 K
c = 11.313 (2) Å0.16 × 0.02 × 0.02 mm
Data collection top
CAD-4
diffractometer
387 reflections with I > 2σ(I)
Absorption correction: gaussian
(JANA2000; Petrícek & Dusek, 2000)
Rint = 0.035
Tmin = 0.420, Tmax = 0.5113 standard reflections every 60 min
2650 measured reflections intensity decay: 0.8%
409 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.01622 parameters
wR(F2) = 0.042Δρmax = 1.07 e Å3
S = 1.00Δρmin = 1.64 e Å3
409 reflections
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Y0.500.20285 (2)0.00457 (7)0.951 (4)
Ca0.500.202850.004570.049
Ba0.50.500.00822 (6)
Ni0000.00560 (11)
O10.5000.0094 (7)
O200.2400 (2)0.14833 (12)0.0081 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Y0.00578 (14)0.00403 (13)0.00390 (12)000
Ca0.005780.004030.00390000
Ba0.01105 (12)0.00640 (11)0.00722 (11)000
Ni0.0039 (2)0.0071 (2)0.00575 (18)000
O10.0076 (12)0.0161 (14)0.0044 (10)000
O20.0096 (6)0.0066 (6)0.0080 (6)000.0018 (4)
Geometric parameters (Å, º) top
Y—O12.2949 (2)Ba—O2viii2.9287 (12)
Y—O22.4107 (10)Ba—O2ix2.9287 (12)
Y—O2i2.4107 (10)Ba—O2x2.9287 (12)
Y—O2ii2.2528 (15)Ba—O2xi2.9287 (12)
Y—O2iii2.2528 (15)Ba—O2xii2.9287 (12)
Y—O2iv2.4107 (10)Ni—O1xiii1.8764 (3)
Y—O2v2.4107 (10)Ni—O11.8764 (3)
Ba—O12.8791 (5)Ni—O22.1740 (15)
Ba—O1vi2.8791 (5)Ni—O2xiv2.1740 (15)
Ba—O22.9287 (12)Ni—O2ix2.1740 (15)
Ba—O2i2.9287 (12)Ni—O2iv2.1740 (15)
Ba—O2vii2.9287 (12)
O1—Y—O275.18 (3)O2i—Ba—O2xi110.08 (3)
O1—Y—O2i75.18 (3)O2i—Ba—O2xii61.47 (4)
O1—Y—O2ii138.36 (3)O2vii—Ba—O2100.31 (2)
O1—Y—O2iii138.36 (3)O2vii—Ba—O2i180
O1—Y—O2iv75.18 (3)O2vii—Ba—O2viii79.69 (2)
O1—Y—O2v75.18 (3)O2vii—Ba—O2ix61.47 (4)
O2—Y—O2i102.22 (4)O2vii—Ba—O2x110.08 (3)
O2—Y—O2ii79.06 (4)O2vii—Ba—O2xi69.92 (3)
O2—Y—O2iii124.90 (3)O2vii—Ba—O2xii118.53 (4)
O2—Y—O2iv69.97 (4)O2viii—Ba—O2180
O2—Y—O2v150.35 (4)O2viii—Ba—O2i100.31 (2)
O2i—Y—O2102.22 (4)O2viii—Ba—O2vii79.69 (2)
O2i—Y—O2ii79.06 (4)O2viii—Ba—O2ix110.08 (3)
O2i—Y—O2iii124.90 (3)O2viii—Ba—O2x61.47 (4)
O2i—Y—O2iv150.35 (4)O2viii—Ba—O2xi118.53 (4)
O2i—Y—O2v69.97 (4)O2viii—Ba—O2xii69.92 (3)
O2ii—Y—O279.06 (4)O2ix—Ba—O269.92 (3)
O2ii—Y—O2i79.06 (4)O2ix—Ba—O2i118.53 (4)
O2ii—Y—O2iii83.28 (5)O2ix—Ba—O2vii61.47 (4)
O2ii—Y—O2iv124.90 (3)O2ix—Ba—O2viii110.08 (3)
O2ii—Y—O2v124.90 (3)O2ix—Ba—O2x79.69 (2)
O2iii—Y—O2124.90 (3)O2ix—Ba—O2xi100.31 (2)
O2iii—Y—O2i124.90 (3)O2ix—Ba—O2xii180
O2iii—Y—O2ii83.28 (5)O2x—Ba—O2118.53 (4)
O2iii—Y—O2iv79.06 (4)O2x—Ba—O2i69.92 (3)
O2iii—Y—O2v79.06 (4)O2x—Ba—O2vii110.08 (3)
O2iv—Y—O269.97 (4)O2x—Ba—O2viii61.47 (4)
O2iv—Y—O2i150.35 (4)O2x—Ba—O2ix79.69 (2)
O2iv—Y—O2ii124.90 (3)O2x—Ba—O2xi180
O2iv—Y—O2iii79.06 (4)O2x—Ba—O2xii100.31 (2)
O2iv—Y—O2v102.22 (4)O2xi—Ba—O261.47 (4)
O2v—Y—O2150.35 (4)O2xi—Ba—O2i110.08 (3)
O2v—Y—O2i69.97 (4)O2xi—Ba—O2vii69.92 (3)
O2v—Y—O2ii124.90 (3)O2xi—Ba—O2viii118.53 (4)
O2v—Y—O2iii79.06 (4)O2xi—Ba—O2ix100.31 (2)
O2v—Y—O2iv102.22 (4)O2xi—Ba—O2x180
O1—Ba—O1vi180O2xi—Ba—O2xii79.69 (2)
O1—Ba—O259.26 (2)O2xii—Ba—O2110.08 (3)
O1—Ba—O2i59.26 (2)O2xii—Ba—O2i61.47 (4)
O1—Ba—O2vii120.74 (2)O2xii—Ba—O2vii118.53 (4)
O1—Ba—O2viii120.74 (2)O2xii—Ba—O2viii69.92 (3)
O1—Ba—O2ix59.26 (2)O2xii—Ba—O2ix180
O1—Ba—O2x59.26 (2)O2xii—Ba—O2x100.31 (2)
O1—Ba—O2xi120.74 (2)O2xii—Ba—O2xi79.69 (2)
O1—Ba—O2xii120.74 (2)O1xiii—Ni—O1180
O1vi—Ba—O1180O1xiii—Ni—O290
O1vi—Ba—O2120.74 (2)O1xiii—Ni—O2xiv90
O1vi—Ba—O2i120.74 (2)O1xiii—Ni—O2ix90
O1vi—Ba—O2vii59.26 (2)O1xiii—Ni—O2iv90
O1vi—Ba—O2viii59.26 (2)O1—Ni—O1xiii180
O1vi—Ba—O2ix120.74 (2)O1—Ni—O290
O1vi—Ba—O2x120.74 (2)O1—Ni—O2xiv90
O1vi—Ba—O2xi59.26 (2)O1—Ni—O2ix90
O1vi—Ba—O2xii59.26 (2)O1—Ni—O2iv90
O2—Ba—O2i79.69 (2)O2—Ni—O2xiv180
O2—Ba—O2vii100.31 (2)O2—Ni—O2ix101.04 (5)
O2—Ba—O2viii180O2—Ni—O2iv78.96 (5)
O2—Ba—O2ix69.92 (3)O2xiv—Ni—O2180
O2—Ba—O2x118.53 (4)O2xiv—Ni—O2ix78.96 (5)
O2—Ba—O2xi61.47 (4)O2xiv—Ni—O2iv101.04 (5)
O2—Ba—O2xii110.08 (3)O2ix—Ni—O2101.04 (5)
O2i—Ba—O279.69 (2)O2ix—Ni—O2xiv78.96 (5)
O2i—Ba—O2vii180O2ix—Ni—O2iv180
O2i—Ba—O2viii100.31 (2)O2iv—Ni—O278.96 (5)
O2i—Ba—O2ix118.53 (4)O2iv—Ni—O2xiv101.04 (5)
O2i—Ba—O2x69.92 (3)O2iv—Ni—O2ix180
Symmetry codes: (i) x+1, y, z; (ii) x+1/2, y+1/2, z+1/2; (iii) x+1/2, y1/2, z+1/2; (iv) x, y, z; (v) x+1, y, z; (vi) x, y+1, z; (vii) x, y+1, z; (viii) x+1, y+1, z; (ix) x, y, z; (x) x+1, y, z; (xi) x, y+1, z; (xii) x+1, y+1, z; (xiii) x1, y, z; (xiv) x, y, z.

Experimental details

Crystal data
Chemical formulaY1.90Ca0.10BaNiO5
Mr449
Crystal system, space groupOrthorhombic, Immm
Temperature (K)293
a, b, c (Å)3.7527 (5), 5.7581 (9), 11.313 (2)
V3)244.46 (6)
Z2
Radiation typeMo Kα
µ (mm1)34.10
Crystal size (mm)0.16 × 0.02 × 0.02
Data collection
DiffractometerCAD-4
diffractometer
Absorption correctionGaussian
(JANA2000; Petrícek & Dusek, 2000)
Tmin, Tmax0.420, 0.511
No. of measured, independent and
observed [I > 2σ(I)] reflections
2650, 409, 387
Rint0.035
(sin θ/λ)max1)0.865
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.016, 0.042, 1.00
No. of reflections409
No. of parameters22
No. of restraints?
Δρmax, Δρmin (e Å3)1.07, 1.64

Computer programs: CAD-4-PC Software (Enraf-Nonius, 1992), CAD-4-PC Software, JANA2000 (Petrícek & Dusek, 2000), JANA2000, DIAMOND (Brandenburg, 1999).

Selected geometric parameters (Å, º) top
Y—O12.2949 (2)Ba—O22.9287 (12)
Y—O22.4107 (10)Ni—O1ii1.8764 (3)
Y—O2i2.2528 (15)Ni—O22.1740 (15)
Ba—O12.8791 (5)
O2—Ni—O2iii101.04 (5)O2—Ni—O2iv78.96 (5)
Symmetry codes: (i) x+1/2, y+1/2, z+1/2; (ii) x1, y, z; (iii) x, y, z; (iv) x, y, z.
 

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