research papers
The structure of the = 2 tubular compound Bi4Sr12Co8O30−δ, bismuth strontium cobalt oxide, was determined by single-crystal X-ray diffraction. This phase of orthorhombic symmetry exhibits a very strong tetragonal pseudosymmetry. The structure consists of 90°-oriented Bi2Sr2CoO6+δ slices, four Co atoms wide, forming [Sr4Co4O13]∞ pillars at their intersection. The Co atoms in these pillars form four corner-sharing CoO5 bipyramids. In the resulting [Co4O13] cluster, an anionic disorder is evidenced and discussed. Then, an accurate description of the particular structure of the pillars is given. Finally, a comparison with the Mn tubular compound Bi3.6Sr12.4Mn8O30−δ is carried out.
Keywords: tubular oxides.
Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768101018444/ck0008sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108768101018444/ck0008Isup2.hkl |
Computing details top
(I) top
Crystal data top
BiCo2Sr3O8.25 | F(000) = 4976 |
Mr = 721.7 | Dx = 6.301 Mg m−3 |
Orthorhombic, C222 | Mo Kα radiation, λ = 0.7107 Å |
a = 23.4782 Å | Cell parameters from 25 reflections |
b = 23.4857 Å | µ = 49.80 mm−1 |
c = 5.5171 Å | T = 293 K |
V = 3042.14 Å3 | Needle, black |
Z = 16 | 0.20 × 0.06 × 0.03 mm |
Data collection top
Brucker-SMART diffractometer | 5185 reflections with 3 |
Absorption correction: gaussian Integration | Rint = 0.038 |
Tmin = 0.050, Tmax = 0.200 | h = → |
27412 measured reflections | k = → |
13706 independent reflections | l = → |
Refinement top
Refinement on F | Weighting scheme based on measured s.u.'s w = 1/σ2(F) |
R[F2 > 2σ(F2)] = 0.059 | (Δ/σ)max = 0.001 |
wR(F2) = 0.049 | Δρmax = 5.6 e Å−3 |
S = 2.66 | Δρmin = −5.6 e Å−3 |
5185 reflections | Extinction correction: B-C type 1 Gaussian isotropic |
165 parameters | Extinction coefficient: 0.040441 |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
x | y | z | Uiso*/Ueq | ||
Bi1 | 0.061551 (18) | 0.055780 (19) | 0.7689 (2) | 0.00694 (13) | |
Bi2 | 0.444236 (18) | 0.061594 (19) | 0.7336 (2) | 0.00782 (13) | |
Co1 | 0.16481 (6) | 0.24775 (8) | 0.2447 (11) | 0.0124 (4) | |
Co2 | 0.05601 (6) | 0.24203 (7) | 0.7537 (9) | 0.0119 (4) | |
Co3 | 0.25214 (7) | 0.16459 (7) | 0.2622 (11) | 0.0114 (5) | |
Co4 | 0.25768 (7) | 0.05615 (7) | 0.7471 (9) | 0.0122 (4) | |
Sr1 | 0.05603 (5) | 0.16706 (5) | 0.2477 (6) | 0.0103 (3) | |
Sr2 | 0.16954 (5) | 0.16468 (4) | 0.7503 (6) | 0.0159 (3) | |
Sr3 | 0.17582 (5) | 0.05396 (6) | 0.2465 (7) | 0.0094 (4) | |
Sr4 | 0.44631 (5) | 0.17588 (6) | 0.2478 (7) | 0.0093 (4) | |
Sr5 | 0.33520 (4) | 0.16952 (5) | 0.7561 (5) | 0.0156 (3) | |
Sr6 | 0.33289 (4) | 0.05591 (6) | 0.2461 (6) | 0.0101 (3) | |
O1 | 0 | 0.2450 (6) | 0 | 0.010 (3)* | |
O2 | 0 | 0.2495 (9) | 0.5 | 0.021 (6)* | |
O3 | 0.1141 (6) | 0.2443 (5) | 0.006 (3) | 0.019 (3)* | |
O4 | 0.1182 (9) | 0.2477 (8) | 0.533 (4) | 0.024 (6)* | |
O5 | 0.2512 (9) | 0.1107 (15) | 0.005 (6) | 0.033 (11)* | |
O6 | 0.2538 (4) | 0.1196 (4) | 0.525 (2) | 0.0027 (17)* | |
O7 | 0.2572 (7) | 0 | 0.5 | 0.016 (4)* | |
O8 | 0.2521 (6) | 0 | 0 | 0.011 (4)* | |
O9 | 0.0561 (3) | 0.1472 (3) | 0.7122 (18) | 0.0036 (15)* | |
O10 | 0.1697 (4) | 0.1653 (4) | 0.252 (3) | 0.020 (2)* | |
O11 | 0.1505 (3) | 0.0547 (4) | 0.749 (2) | 0.0131 (16)* | |
O12 | 0.5544 (3) | 0.1496 (3) | 0.250 (2) | 0.0120 (16)* | |
O13 | 0.6656 (4) | 0.1689 (4) | 0.766 (3) | 0.022 (2)* | |
O14 | 0.6475 (3) | 0.0561 (3) | 0.2126 (18) | 0.0056 (15)* | |
O15 | 0.0691 (3) | 0.0623 (4) | 0.1427 (17) | 0.0124 (19)* | |
O16 | 0.5617 (4) | 0.0702 (4) | 0.6424 (17) | 0.017 (2)* | |
O17 | 0.25 | 0.25 | 0.25 | 0.181852 | |
O18 | 0.25 | 0.25 | 0.75 | 0.056138 |
Atomic displacement parameters (Å2) top
U11 | U22 | U33 | U12 | U13 | U23 | |
Bi1 | 0.00683 (17) | 0.00604 (14) | 0.0079 (3) | 0.00025 (17) | −0.0008 (2) | 0.0003 (3) |
Bi2 | 0.00655 (16) | 0.00595 (15) | 0.0110 (3) | 0.00048 (17) | −0.0007 (3) | 0.0000 (2) |
Co1 | 0.0108 (7) | 0.0061 (6) | 0.0202 (10) | 0.0000 (6) | −0.0071 (17) | −0.0022 (8) |
Co2 | 0.0068 (6) | 0.0214 (8) | 0.0074 (8) | 0.0012 (6) | −0.0058 (12) | 0.0043 (12) |
Co3 | 0.0069 (7) | 0.0099 (7) | 0.0174 (12) | −0.0010 (6) | −0.0025 (8) | −0.0048 (15) |
Co4 | 0.0223 (8) | 0.0061 (6) | 0.0083 (8) | −0.0008 (6) | 0.0047 (12) | −0.0020 (13) |
Sr1 | 0.0089 (4) | 0.0081 (4) | 0.0140 (7) | 0.0014 (4) | −0.0022 (9) | 0.0011 (8) |
Sr2 | 0.0140 (4) | 0.0121 (4) | 0.0217 (7) | −0.0021 (4) | −0.0031 (9) | 0.0008 (7) |
Sr3 | 0.0082 (5) | 0.0078 (5) | 0.0123 (9) | 0.0010 (4) | 0.0029 (11) | 0.0047 (11) |
Sr4 | 0.0086 (5) | 0.0072 (5) | 0.0120 (9) | 0.0008 (4) | 0.0042 (11) | 0.0009 (11) |
Sr5 | 0.0139 (4) | 0.0133 (4) | 0.0195 (7) | −0.0006 (4) | 0.0015 (7) | 0.0021 (9) |
Sr6 | 0.0086 (4) | 0.0086 (4) | 0.0132 (7) | −0.0004 (4) | 0.0034 (7) | −0.0058 (9) |
O17 | 0.012334 | 0.007316 | 0.525906 | −0.006822 | 0 | 0 |
O18 | 0.024537 | 0.011623 | 0.132254 | −0.011415 | 0 | 0 |
Bond lengths (Å) top
Bi1—Bi1i | 3.9010 (6) | Co2—O12xii | 4.549 (10) |
Bi1—Bi1ii | 3.9580 (12) | Co2—O12xvii | 2.546 (7) |
Bi1—Bi1iii | 3.6564 (12) | Co2—O13xvii | 4.385 (14) |
Bi1—Bi1iv | 4.1418 (12) | Co2—O13xviii | 4.244 (14) |
Bi1—Bi1v | 3.8546 (11) | Co2—O15vi | 4.745 (10) |
Bi1—Co2 | 4.3769 (18) | Co2—O16xvii | 4.923 (10) |
Bi1—Co4 | 4.6063 (17) | Co2—O18 | 4.5584 (15) |
Bi1—Sr1 | 3.888 (3) | Co3—Co1 | 2.833 (2) |
Bi1—Sr1vi | 3.718 (3) | Co3—Co1xi | 2.837 (2) |
Bi1—Sr1iv | 3.8026 (12) | Co3—Co3xi | 4.013 (2) |
Bi1—Sr2 | 3.6028 (12) | Co3—Co4xiv | 3.818 (6) |
Bi1—Sr3 | 3.938 (3) | Co3—Co4 | 3.696 (6) |
Bi1—Sr3vi | 3.761 (3) | Co3—Sr1 | 4.605 (2) |
Bi1—Sr3ii | 3.7212 (13) | Co3—Sr2xiv | 3.426 (6) |
Bi1—O1vi | 4.845 (14) | Co3—Sr2 | 3.319 (6) |
Bi1—O2 | 4.999 (18) | Co3—Sr3 | 3.158 (2) |
Bi1—O3vi | 4.780 (13) | Co3—Sr4 | 4.567 (2) |
Bi1—O4 | 4.876 (19) | Co3—Sr5xiv | 3.408 (5) |
Bi1—O5vi | 4.82 (2) | Co3—Sr5 | 3.353 (5) |
Bi1—O6 | 4.943 (9) | Co3—Sr6 | 3.181 (2) |
Bi1—O8vi | 4.834 (13) | Co3—O3 | 4.000 (14) |
Bi1—O9 | 2.173 (7) | Co3—O3xi | 4.053 (14) |
Bi1—O9iv | 4.392 (8) | Co3—O4 | 3.99 (2) |
Bi1—O9v | 4.521 (8) | Co3—O4xi | 3.97 (2) |
Bi1—O10 | 4.601 (13) | Co3—O5 | 1.90 (3) |
Bi1—O10vi | 4.491 (13) | Co3—O5vi | 4.29 (3) |
Bi1—O11 | 2.092 (7) | Co3—O6xiv | 4.201 (12) |
Bi1—O11ii | 4.390 (10) | Co3—O6 | 1.795 (12) |
Bi1—O11iii | 4.261 (10) | Co3—O7 | 4.084 (2) |
Bi1—O15 | 3.463 (9) | Co3—O8 | 4.127 (3) |
Bi1—O15vi | 2.076 (9) | Co3—O10 | 1.937 (9) |
Bi1—O15vii | 4.621 (9) | Co3—O10xi | 4.398 (9) |
Bi1—O15ii | 2.822 (10) | Co3—O11xiv | 4.512 (11) |
Bi1—O15iv | 3.110 (8) | Co3—O11 | 4.425 (11) |
Bi2—Bi2viii | 3.9021 (6) | Co3—O13xvii | 4.409 (10) |
Bi2—Bi2ii | 3.8748 (12) | Co3—O13ix | 1.940 (9) |
Bi2—Bi2iii | 4.1245 (13) | Co3—O14xix | 4.347 (9) |
Bi2—Bi2ix | 3.6742 (12) | Co3—O14ix | 4.520 (9) |
Bi2—Bi2x | 3.9367 (13) | Co3—O15 | 4.967 (9) |
Bi2—Co2xi | 4.6134 (18) | Co3—O16ix | 4.928 (9) |
Bi2—Co4 | 4.3825 (17) | Co3—O17 | 2.0076 (17) |
Bi2—Sr4 | 3.793 (3) | Co3—O18xiv | 3.466 (5) |
Bi2—Sr4vi | 3.906 (3) | Co3—O18 | 3.357 (5) |
Bi2—Sr4ix | 3.7174 (14) | Co4—Bi1 | 4.6063 (17) |
Bi2—Sr5 | 3.6048 (12) | Co4—Bi2 | 4.3825 (17) |
Bi2—Sr6 | 3.753 (2) | Co4—Co3 | 3.696 (6) |
Bi2—Sr6vi | 3.853 (2) | Co4—Co3vi | 3.818 (6) |
Bi2—Sr6ii | 3.8029 (13) | Co4—Co4ii | 3.793 (5) |
Bi2—O1xii | 4.949 (14) | Co4—Co4iii | 3.840 (5) |
Bi2—O2xi | 4.802 (19) | Co4—Sr2 | 3.283 (2) |
Bi2—O3xii | 4.992 (13) | Co4—Sr3 | 3.365 (5) |
Bi2—O4xi | 4.840 (19) | Co4—Sr3vi | 3.360 (5) |
Bi2—O5vi | 4.91 (2) | Co4—Sr3ii | 3.222 (2) |
Bi2—O6 | 4.813 (9) | Co4—Sr5 | 3.226 (2) |
Bi2—O7 | 4.800 (15) | Co4—Sr6 | 3.280 (5) |
Bi2—O8vi | 4.959 (13) | Co4—Sr6vi | 3.271 (5) |
Bi2—O12 | 4.254 (10) | Co4—Sr6ii | 3.170 (2) |
Bi2—O12vi | 4.367 (10) | Co4—O5 | 4.29 (3) |
Bi2—O12ix | 2.069 (7) | Co4—O5vi | 1.92 (3) |
Bi2—O13ix | 4.540 (14) | Co4—O5ii | 4.15 (3) |
Bi2—O13x | 4.541 (14) | Co4—O6 | 1.931 (11) |
Bi2—O14viii | 4.533 (9) | Co4—O6vi | 4.545 (12) |
Bi2—O14xiii | 4.390 (9) | Co4—O6ii | 4.394 (10) |
Bi2—O14ix | 2.178 (6) | Co4—O7 | 1.897 (4) |
Bi2—O16 | 2.811 (9) | Co4—O7vi | 4.358 (5) |
Bi2—O16viii | 3.140 (10) | Co4—O8 | 4.329 (5) |
Bi2—O16ii | 4.636 (10) | Co4—O8vi | 1.924 (4) |
Bi2—O16ix | 2.089 (10) | Co4—O10 | 4.276 (14) |
Bi2—O16x | 3.452 (10) | Co4—O10vi | 4.314 (14) |
Co1—Co1xi | 4.002 (2) | Co4—O11 | 2.516 (7) |
Co1—Co2xiv | 3.726 (6) | Co4—O11ii | 4.540 (10) |
Co1—Co2 | 3.798 (6) | Co4—O11iii | 4.563 (10) |
Co1—Co3 | 2.833 (2) | Co4—O12ix | 4.927 (7) |
Co1—Co3xi | 2.837 (2) | Co4—O13ix | 4.275 (15) |
Co1—Sr1 | 3.180 (2) | Co4—O13x | 4.179 (14) |
Co1—Sr2xiv | 3.356 (6) | Co4—O14viii | 4.539 (9) |
Co1—Sr2 | 3.406 (6) | Co4—O14xiii | 4.302 (9) |
Co1—Sr3 | 4.559 (2) | Co4—O14ix | 2.237 (6) |
Co1—Sr4xi | 3.166 (2) | Co4—O15vi | 4.938 (9) |
Co1—Sr5xv | 3.323 (6) | Co4—O16ix | 4.765 (10) |
Co1—Sr5xi | 3.425 (6) | Co4—O18 | 4.5562 (17) |
Co1—Sr6xi | 4.611 (2) | Sr1—O1 | 2.637 (11) |
Co1—O1 | 4.099 (2) | Sr1—O2 | 2.724 (14) |
Co1—O2 | 4.118 (2) | Sr1—O3 | 2.632 (14) |
Co1—O3 | 1.776 (15) | Sr1—O4 | 2.86 (2) |
Co1—O3vi | 4.367 (16) | Sr1—O9xiv | 2.991 (11) |
Co1—O4xiv | 4.07 (2) | Sr1—O9 | 2.605 (11) |
Co1—O4 | 1.93 (2) | Sr1—O9iv | 2.684 (7) |
Co1—O5 | 4.03 (3) | Sr1—O10 | 2.669 (9) |
Co1—O5xi | 4.08 (3) | Sr1—O15 | 2.546 (10) |
Co1—O6 | 3.977 (10) | Sr2—O3vi | 2.680 (14) |
Co1—O6xi | 3.968 (10) | Sr2—O4 | 2.59 (2) |
Co1—O9xiv | 4.552 (9) | Sr2—O5vi | 2.69 (3) |
Co1—O9 | 4.329 (9) | Sr2—O6 | 2.565 (10) |
Co1—O10 | 1.941 (10) | Sr2—O9 | 2.702 (7) |
Co1—O10xi | 4.391 (9) | Sr2—O10 | 2.747 (19) |
Co1—O12xvi | 4.469 (11) | Sr2—O10vi | 2.770 (19) |
Co1—O12xvii | 4.506 (11) | Sr2—O11 | 2.622 (9) |
Co1—O13xvii | 1.958 (10) | Sr2—O18 | 2.7538 (11) |
Co1—O13ix | 4.391 (9) | Sr3—O5 | 2.59 (3) |
Co1—O15 | 4.933 (10) | Sr3—O6 | 2.845 (10) |
Co1—O16xvii | 4.952 (10) | Sr3—O7 | 2.686 (12) |
Co1—O17 | 2.0010 (14) | Sr3—O8 | 2.582 (10) |
Co1—O18xiv | 3.384 (5) | Sr3—O10 | 2.618 (9) |
Co1—O18 | 3.431 (5) | Sr3—O11xiv | 2.806 (13) |
Co2—Bi1 | 4.3769 (18) | Sr3—O11 | 2.838 (13) |
Co2—Bi2xi | 4.6134 (18) | Sr3—O11ii | 2.620 (9) |
Co2—Co1 | 3.798 (6) | Sr3—O15 | 2.578 (8) |
Co2—Co1vi | 3.726 (6) | Sr4—O1xi | 2.628 (11) |
Co2—Co2iv | 3.841 (5) | Sr4—O2xi | 2.568 (14) |
Co2—Co2v | 3.782 (5) | Sr4—O3xi | 2.702 (14) |
Co2—Sr1 | 3.301 (5) | Sr4—O4xi | 2.83 (2) |
Co2—Sr1vi | 3.245 (5) | Sr4—O12 | 2.613 (7) |
Co2—Sr1iv | 3.165 (2) | Sr4—O12xix | 2.813 (13) |
Co2—Sr2 | 3.2257 (19) | Sr4—O12ix | 2.840 (13) |
Co2—Sr4xi | 3.393 (5) | Sr4—O13ix | 2.634 (9) |
Co2—Sr4xii | 3.339 (5) | Sr4—O16ix | 2.561 (10) |
Co2—Sr4xvii | 3.217 (2) | Sr5—O3xii | 2.723 (13) |
Co2—Sr5xi | 3.2923 (19) | Sr5—O4xi | 2.55 (2) |
Co2—O1 | 4.362 (5) | Sr5—O5vi | 2.77 (3) |
Co2—O1vi | 1.892 (4) | Sr5—O6 | 2.578 (10) |
Co2—O2 | 1.929 (4) | Sr5—O12ix | 2.633 (7) |
Co2—O2vi | 4.326 (5) | Sr5—O13ix | 2.882 (19) |
Co2—O3 | 4.344 (15) | Sr5—O13x | 2.635 (19) |
Co2—O3vi | 1.951 (15) | Sr5—O14ix | 2.699 (8) |
Co2—O3iv | 4.209 (14) | Sr5—O18 | 2.7521 (11) |
Co2—O4 | 1.90 (2) | Sr6—O5 | 2.67 (3) |
Co2—O4vi | 4.55 (2) | Sr6—O6 | 2.838 (10) |
Co2—O4iv | 4.39 (2) | Sr6—O7 | 2.616 (12) |
Co2—O9 | 2.239 (7) | Sr6—O8 | 2.676 (10) |
Co2—O9iv | 4.301 (9) | Sr6—O13ix | 2.655 (10) |
Co2—O9v | 4.536 (9) | Sr6—O14viii | 2.678 (8) |
Co2—O10 | 4.245 (14) | Sr6—O14xix | 2.572 (10) |
Co2—O10vi | 4.236 (14) | Sr6—O14ix | 3.021 (10) |
Co2—O11 | 4.928 (9) | Sr6—O16ix | 2.572 (9) |
Co2—O12xi | 4.575 (10) |
Symmetry codes: (i) −x, −y, z; (ii) x, −y, −z+1; (iii) x, −y, −z+2; (iv) −x, y, −z+1; (v) −x, y, −z+2; (vi) x, y, z+1; (vii) −x, −y, z+1; (viii) −x+1, −y, z; (ix) −x+1, y, −z+1; (x) −x+1, y, −z+2; (xi) −x+1/2, −y+1/2, z; (xii) −x+1/2, −y+1/2, z+1; (xiii) −x+1, −y, z+1; (xiv) x, y, z−1; (xv) −x+1/2, −y+1/2, z−1; (xvi) x−1/2, −y+1/2, −z; (xvii) x−1/2, −y+1/2, −z+1; (xviii) x−1/2, −y+1/2, −z+2; (xix) −x+1, y, −z. |