inorganic compounds
Lithium manganese oxide crystals with composition (Li0.91Mn0.09)Mn2O4 were synthesized by a flux method. The crystals have a structure closely related to that of the cubic spinel LiMn2O4, but 9% of the lithium ions in the tetrahedral 4a site are substituted by Mn2+ ions. This substitution lowers the average Mn oxidation state below 3.5+, resulting in a Jahn-Teller distortion of the MnO6 octahedron.
Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270100019430/sk1365sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270100019430/sk1365Isup2.hkl |
Computing details top
Data collection: STOE IPDS; cell refinement: Rigaku AFC-6R; data reduction: X-RED and X-SHAPE (Stoe & Cie, 1996); program(s) used to refine structure: DUPALS (Lundgren, 1983); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: DISTAN (Lundgren, 1983).
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Crystal data top
(Li0.91Mn0.09)Mn2O4 | ? #Insert any comments here. |
Mr = 185.13 | Dx = 4.304 Mg m−3 |
Tetragonal, I41/amd | Mo Kα1 radiation, λ = 0.71073 Å |
Hall symbol: -I 4bd 2 | Cell parameters from 25 reflections |
a = 5.7502 (9) Å | θ = 19.0–20.0° |
c = 8.637 (3) Å | µ = 8.78 mm−1 |
V = 285.58 (11) Å3 | T = 293 K |
Z = 4 | Octahedral, black |
F(000) = 476 | 0.3 × 0.3 × 0.2 mm |
Data collection top
STOE IPDS diffractometer | 103 independent reflections |
Radiation source: xray tube | 1225 reflections with Inet > −15.0σ(Inet) |
Graphite monochromator | Rint = 0.049 |
ω scan b/P/b | θmax = 28.0°, θmin = 4.3° |
Absorption correction: numerical JANA'98 (Petriçek & Dušek, 1997) | h = −7→7 |
Tmin = 0.182, Tmax = 0.377 | k = −7→7 |
1225 measured reflections | l = −11→11 |
Refinement top
Refinement on F2 | w = 1/[σ2(F)2 + 0.01F2] |
Least-squares matrix: full | (Δ/σ)max = 0.1 |
R[F2 > 2σ(F2)] = 0.038 | Δρmax = 0.52 e Å−3 |
wR(F2) = 0.083 | Δρmin = −0.55 e Å−3 |
S = 3.94 | Extinction correction: Becker & Coppens (1974), isotropic type 2 |
1225 reflections | Extinction coefficient: 0.8 (1) x 103 |
14 parameters |
Special details top
Experimental. ? #Insert any special details here. |
Refinement. ? #Insert any special details here. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
x | y | z | Uiso*/Ueq | Occ. (<1) | |
Mn1 | 0.5000 | 0.0000 | 0.0000 | 0.0103 (2) | |
O | 0.2762 (2) | 0.2500 | 0.01191 (17) | 0.0195 (8) | |
Mn2 | 0.0000 | 0.7500 | 0.1250 | 0.0190 (8)* | 0.093 (3) |
Li | 0.0000 | 0.7500 | 0.1250 | 0.0190 (8)* | 0.907 (3) |
Atomic displacement parameters (Å2) top
U11 | U22 | U33 | U12 | U13 | U23 | |
Mn1 | 0.0079 (2) | 0.0070 (2) | 0.0159 (2) | 0.0000 | 0.0000 | −0.00166 (10) |
O | 0.0125 (8) | 0.0125 (9) | 0.0336 (9) | 0.0000 | −0.0028 (7) | 0.0000 |
Geometric parameters (Å, º) top
Mn1i—Mn1 | 2.9657 (5) | Oi—O | 2.670 (3) |
Mn1ii—Mn1 | 2.8751 (4) | Ov—O | 2.574 (3) |
Mn1—O | 1.9322 (10) | Ovi—O | 2.8824 (5) |
Mn1—Oiii | 2.0619 (16) | Mn2vii—O | 1.9800 (15) |
Oiv—O | 2.9734 (5) | Livii—O | 1.9800 (15) |
O—Mn1—Oiii | 96.17 (6) | Mn1—O—Li | 120.16 (5) |
O—Mn1—Oviii | 180 | Mn1i—O—Mn2vii | 122.48 (7) |
O—Mn1—Ov | 83.53 (6) | Mn1—O—Li | 122.48 (7) |
O—Mn1—Ovi | 96.47 (6) | Oxi—Mn2—Oxii | 110.90 (4) |
O—Mn1—Oix | 83.83 (6) | Oxi—Mn2—Oxiii | 106.66 (9) |
Mn1—O—Mn1i | 95.84 (5) | Oxi—Li—Oxii | 110.90 (4) |
Mn1—O—Mn1x | 96.14 (6) | Oxi—Li—Oxiii | 106.66 (9) |
Mn1—O—Mn2vii | 120.16 (5) |
Symmetry codes: (i) y+1/4, −x+3/4, −z+1/4; (ii) −x+1, −y−1/2, z; (iii) y+1/4, −x+1/4, z−1/4; (iv) −y+1/4, x−1/4, z+1/4; (v) −x+1, y, z; (vi) x, −y, −z; (vii) x, y−1/2, −z; (viii) −x+1, −y, −z; (ix) −y+3/4, x−1/4, −z+1/4; (x) −x+1, −y+1/2, z; (xi) −y+1/4, x+3/4, z+1/4; (xii) −x, y+1/2, −z; (xiii) y−1/4, −x+3/4, z+1/4. |