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
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (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
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
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.
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.
Crystal data top
Y1.90Ca0.10BaNiO5 | Dx = 6.097 Mg m−3 |
Mr = 449 | Mo Kα radiation, λ = 0.71069 Å |
Orthorhombic, Immm | Cell parameters from 25 reflections |
a = 3.7527 (5) Å | θ = 7.4–15.0° |
b = 5.7581 (9) Å | µ = 34.10 mm−1 |
c = 11.313 (2) Å | T = 293 K |
V = 244.46 (6) Å3 | Thick needle, black |
Z = 2 | 0.16 × 0.02 × 0.02 mm |
F(000) = 400 | |
Data collection top
CAD-4 diffractometer | Rint = 0.035 |
ω scans | θmax = 38.0°, θmin = 3.6° |
Absorption correction: gaussian (JANA2000; Petrícek & Dusek, 2000) | h = −6→6 |
Tmin = 0.420, Tmax = 0.511 | k = −9→9 |
2650 measured reflections | l = −19→19 |
409 independent reflections | 3 standard reflections every 60 min |
387 reflections with I > 2σ(I) | intensity decay: 0.8% |
Refinement top
Refinement on F2 | Weighting 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) = 0.042 | Δρmax = 1.07 e Å−3 |
S = 1.00 | Δρmin = −1.64 e Å−3 |
409 reflections | Extinction correction: B-C type 1 Lorentzian isotropic |
22 parameters | Extinction coefficient: 0.45 (2) |
Crystal data top
Y1.90Ca0.10BaNiO5 | V = 244.46 (6) Å3 |
Mr = 449 | Z = 2 |
Orthorhombic, Immm | Mo Kα radiation |
a = 3.7527 (5) Å | µ = 34.10 mm−1 |
b = 5.7581 (9) Å | T = 293 K |
c = 11.313 (2) Å | 0.16 × 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 = 0.511 | 3 standard reflections every 60 min |
2650 measured reflections | intensity decay: 0.8% |
409 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.016 | 22 parameters |
wR(F2) = 0.042 | Δρmax = 1.07 e Å−3 |
S = 1.00 | Δρmin = −1.64 e Å−3 |
409 reflections | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
Y | 0.5 | 0 | 0.20285 (2) | 0.00457 (7) | 0.951 (4) |
Ca | 0.5 | 0 | 0.20285 | 0.00457 | 0.049 |
Ba | 0.5 | 0.5 | 0 | 0.00822 (6) | |
Ni | 0 | 0 | 0 | 0.00560 (11) | |
O1 | 0.5 | 0 | 0 | 0.0094 (7) | |
O2 | 0 | 0.2400 (2) | 0.14833 (12) | 0.0081 (3) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Y | 0.00578 (14) | 0.00403 (13) | 0.00390 (12) | 0 | 0 | 0 |
Ca | 0.00578 | 0.00403 | 0.00390 | 0 | 0 | 0 |
Ba | 0.01105 (12) | 0.00640 (11) | 0.00722 (11) | 0 | 0 | 0 |
Ni | 0.0039 (2) | 0.0071 (2) | 0.00575 (18) | 0 | 0 | 0 |
O1 | 0.0076 (12) | 0.0161 (14) | 0.0044 (10) | 0 | 0 | 0 |
O2 | 0.0096 (6) | 0.0066 (6) | 0.0080 (6) | 0 | 0 | −0.0018 (4) |
Geometric parameters (Å, º) top
Y—O1 | 2.2949 (2) | Ba—O2viii | 2.9287 (12) |
Y—O2 | 2.4107 (10) | Ba—O2ix | 2.9287 (12) |
Y—O2i | 2.4107 (10) | Ba—O2x | 2.9287 (12) |
Y—O2ii | 2.2528 (15) | Ba—O2xi | 2.9287 (12) |
Y—O2iii | 2.2528 (15) | Ba—O2xii | 2.9287 (12) |
Y—O2iv | 2.4107 (10) | Ni—O1xiii | 1.8764 (3) |
Y—O2v | 2.4107 (10) | Ni—O1 | 1.8764 (3) |
Ba—O1 | 2.8791 (5) | Ni—O2 | 2.1740 (15) |
Ba—O1vi | 2.8791 (5) | Ni—O2xiv | 2.1740 (15) |
Ba—O2 | 2.9287 (12) | Ni—O2ix | 2.1740 (15) |
Ba—O2i | 2.9287 (12) | Ni—O2iv | 2.1740 (15) |
Ba—O2vii | 2.9287 (12) | | |
| | | |
O1—Y—O2 | 75.18 (3) | O2i—Ba—O2xi | 110.08 (3) |
O1—Y—O2i | 75.18 (3) | O2i—Ba—O2xii | 61.47 (4) |
O1—Y—O2ii | 138.36 (3) | O2vii—Ba—O2 | 100.31 (2) |
O1—Y—O2iii | 138.36 (3) | O2vii—Ba—O2i | 180 |
O1—Y—O2iv | 75.18 (3) | O2vii—Ba—O2viii | 79.69 (2) |
O1—Y—O2v | 75.18 (3) | O2vii—Ba—O2ix | 61.47 (4) |
O2—Y—O2i | 102.22 (4) | O2vii—Ba—O2x | 110.08 (3) |
O2—Y—O2ii | 79.06 (4) | O2vii—Ba—O2xi | 69.92 (3) |
O2—Y—O2iii | 124.90 (3) | O2vii—Ba—O2xii | 118.53 (4) |
O2—Y—O2iv | 69.97 (4) | O2viii—Ba—O2 | 180 |
O2—Y—O2v | 150.35 (4) | O2viii—Ba—O2i | 100.31 (2) |
O2i—Y—O2 | 102.22 (4) | O2viii—Ba—O2vii | 79.69 (2) |
O2i—Y—O2ii | 79.06 (4) | O2viii—Ba—O2ix | 110.08 (3) |
O2i—Y—O2iii | 124.90 (3) | O2viii—Ba—O2x | 61.47 (4) |
O2i—Y—O2iv | 150.35 (4) | O2viii—Ba—O2xi | 118.53 (4) |
O2i—Y—O2v | 69.97 (4) | O2viii—Ba—O2xii | 69.92 (3) |
O2ii—Y—O2 | 79.06 (4) | O2ix—Ba—O2 | 69.92 (3) |
O2ii—Y—O2i | 79.06 (4) | O2ix—Ba—O2i | 118.53 (4) |
O2ii—Y—O2iii | 83.28 (5) | O2ix—Ba—O2vii | 61.47 (4) |
O2ii—Y—O2iv | 124.90 (3) | O2ix—Ba—O2viii | 110.08 (3) |
O2ii—Y—O2v | 124.90 (3) | O2ix—Ba—O2x | 79.69 (2) |
O2iii—Y—O2 | 124.90 (3) | O2ix—Ba—O2xi | 100.31 (2) |
O2iii—Y—O2i | 124.90 (3) | O2ix—Ba—O2xii | 180 |
O2iii—Y—O2ii | 83.28 (5) | O2x—Ba—O2 | 118.53 (4) |
O2iii—Y—O2iv | 79.06 (4) | O2x—Ba—O2i | 69.92 (3) |
O2iii—Y—O2v | 79.06 (4) | O2x—Ba—O2vii | 110.08 (3) |
O2iv—Y—O2 | 69.97 (4) | O2x—Ba—O2viii | 61.47 (4) |
O2iv—Y—O2i | 150.35 (4) | O2x—Ba—O2ix | 79.69 (2) |
O2iv—Y—O2ii | 124.90 (3) | O2x—Ba—O2xi | 180 |
O2iv—Y—O2iii | 79.06 (4) | O2x—Ba—O2xii | 100.31 (2) |
O2iv—Y—O2v | 102.22 (4) | O2xi—Ba—O2 | 61.47 (4) |
O2v—Y—O2 | 150.35 (4) | O2xi—Ba—O2i | 110.08 (3) |
O2v—Y—O2i | 69.97 (4) | O2xi—Ba—O2vii | 69.92 (3) |
O2v—Y—O2ii | 124.90 (3) | O2xi—Ba—O2viii | 118.53 (4) |
O2v—Y—O2iii | 79.06 (4) | O2xi—Ba—O2ix | 100.31 (2) |
O2v—Y—O2iv | 102.22 (4) | O2xi—Ba—O2x | 180 |
O1—Ba—O1vi | 180 | O2xi—Ba—O2xii | 79.69 (2) |
O1—Ba—O2 | 59.26 (2) | O2xii—Ba—O2 | 110.08 (3) |
O1—Ba—O2i | 59.26 (2) | O2xii—Ba—O2i | 61.47 (4) |
O1—Ba—O2vii | 120.74 (2) | O2xii—Ba—O2vii | 118.53 (4) |
O1—Ba—O2viii | 120.74 (2) | O2xii—Ba—O2viii | 69.92 (3) |
O1—Ba—O2ix | 59.26 (2) | O2xii—Ba—O2ix | 180 |
O1—Ba—O2x | 59.26 (2) | O2xii—Ba—O2x | 100.31 (2) |
O1—Ba—O2xi | 120.74 (2) | O2xii—Ba—O2xi | 79.69 (2) |
O1—Ba—O2xii | 120.74 (2) | O1xiii—Ni—O1 | 180 |
O1vi—Ba—O1 | 180 | O1xiii—Ni—O2 | 90 |
O1vi—Ba—O2 | 120.74 (2) | O1xiii—Ni—O2xiv | 90 |
O1vi—Ba—O2i | 120.74 (2) | O1xiii—Ni—O2ix | 90 |
O1vi—Ba—O2vii | 59.26 (2) | O1xiii—Ni—O2iv | 90 |
O1vi—Ba—O2viii | 59.26 (2) | O1—Ni—O1xiii | 180 |
O1vi—Ba—O2ix | 120.74 (2) | O1—Ni—O2 | 90 |
O1vi—Ba—O2x | 120.74 (2) | O1—Ni—O2xiv | 90 |
O1vi—Ba—O2xi | 59.26 (2) | O1—Ni—O2ix | 90 |
O1vi—Ba—O2xii | 59.26 (2) | O1—Ni—O2iv | 90 |
O2—Ba—O2i | 79.69 (2) | O2—Ni—O2xiv | 180 |
O2—Ba—O2vii | 100.31 (2) | O2—Ni—O2ix | 101.04 (5) |
O2—Ba—O2viii | 180 | O2—Ni—O2iv | 78.96 (5) |
O2—Ba—O2ix | 69.92 (3) | O2xiv—Ni—O2 | 180 |
O2—Ba—O2x | 118.53 (4) | O2xiv—Ni—O2ix | 78.96 (5) |
O2—Ba—O2xi | 61.47 (4) | O2xiv—Ni—O2iv | 101.04 (5) |
O2—Ba—O2xii | 110.08 (3) | O2ix—Ni—O2 | 101.04 (5) |
O2i—Ba—O2 | 79.69 (2) | O2ix—Ni—O2xiv | 78.96 (5) |
O2i—Ba—O2vii | 180 | O2ix—Ni—O2iv | 180 |
O2i—Ba—O2viii | 100.31 (2) | O2iv—Ni—O2 | 78.96 (5) |
O2i—Ba—O2ix | 118.53 (4) | O2iv—Ni—O2xiv | 101.04 (5) |
O2i—Ba—O2x | 69.92 (3) | O2iv—Ni—O2ix | 180 |
Symmetry codes: (i) x+1, y, z; (ii) −x+1/2, −y+1/2, −z+1/2; (iii) x+1/2, y−1/2, −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) x−1, y, z; (xiv) −x, −y, −z. |
Experimental details
Crystal data |
Chemical formula | Y1.90Ca0.10BaNiO5 |
Mr | 449 |
Crystal system, space group | Orthorhombic, Immm |
Temperature (K) | 293 |
a, b, c (Å) | 3.7527 (5), 5.7581 (9), 11.313 (2) |
V (Å3) | 244.46 (6) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 34.10 |
Crystal size (mm) | 0.16 × 0.02 × 0.02 |
|
Data collection |
Diffractometer | CAD-4 diffractometer |
Absorption correction | Gaussian (JANA2000; Petrícek & Dusek, 2000) |
Tmin, Tmax | 0.420, 0.511 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2650, 409, 387 |
Rint | 0.035 |
(sin θ/λ)max (Å−1) | 0.865 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.016, 0.042, 1.00 |
No. of reflections | 409 |
No. of parameters | 22 |
No. of restraints | ? |
Δρmax, Δρmin (e Å−3) | 1.07, −1.64 |
Selected geometric parameters (Å, º) topY—O1 | 2.2949 (2) | Ba—O2 | 2.9287 (12) |
Y—O2 | 2.4107 (10) | Ni—O1ii | 1.8764 (3) |
Y—O2i | 2.2528 (15) | Ni—O2 | 2.1740 (15) |
Ba—O1 | 2.8791 (5) | | |
| | | |
O2—Ni—O2iii | 101.04 (5) | O2—Ni—O2iv | 78.96 (5) |
Symmetry codes: (i) −x+1/2, −y+1/2, −z+1/2; (ii) x−1, y, z; (iii) x, y, −z; (iv) −x, −y, z. |
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).