Single crystals of europium(III) scandate(III), with ideal formula EuScO3, were grown from the melt using the micro-pulling-down method. The title compound crystallizes in an ortho­rhom­bic distorted perovskite-type structure, where Eu occupies the eightfold coordinated A sites (site symmetry m) and Sc resides on the centres of corner-sharing [ScO6] octa­hedra (B sites with site symmetry ). The structure of EuScO3 has been reported previously based on powder diffraction data [Liferovich & Mitchell (2004). J. Solid State Chem. 
               177, 2188–2197]. The results of the current redetermination based on single-crystal diffraction data shows an improvement in the precision of the structral and geometric parameters and reveals a defect-type structure. Site-occupancy refinements indicate an Eu deficiency on the A site coupled with O defects on one of the two O-atom positions. The crystallochemical formula of the investigated sample may thus be written as A(□0.032Eu0.968)BScO2.952

Boža Veličkov

Dirk Maier

Liferovich

Maier

Sheldrick

Veličkov

Volker Kahlenberg

Zhao

English

PubMed

Single crystals of europium(III) scandate(III), with ideal formula EuScO3, were grown from the melt using the micro-pulling-down method. The title compound crystallizes in an orthorhombic distorted perovskite-type structure, where Eu occupies the eightfold coordinated A sites (site symmetry m) and Sc resides on the centres of corner-sharing [ScO6] octahedra (B sites with site symmetry overline{1}). The structure of EuScO3 has been reported previously based on powder diffraction data [Liferovich &amp; Mitchell (2004). J. Solid State Chem. 177, 2188&#8211;2197]. The results of the current redetermination based on single-crystal diffraction data shows an improvement in the precision of the structral and geometric parameters and reveals a defect-type structure. Site-occupancy refinements indicate an Eu deficiency on the A site coupled with O defects on one of the two O-atom positions. The crystallochemical formula of the investigated sample may thus be written as A(&#9633;0.032Eu0.968)BScO2.952

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Redetermination of EuScO3

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Redetermination of EuScO
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Single crystals of europium(III) scandate(III), with ideal formula EuScO3, were grown from the melt using the micro-pulling-down method. The title compound crystallizes in an ortho-rhom-bic distorted perovskite-type structure, where Eu occupies the eightfold coordinated A sites (site symmetry m) and Sc resides on the centres of corner-sharing [ScO6] octa-hedra (B sites with site symmetry ). The structure of EuScO3 has been reported previously based on powder diffraction data [Liferovich & Mitchell (2004). J. Solid State Chem. 177, 2188-2197]. The results of the current redetermination based on single-crystal diffraction data shows an improvement in the precision of the structral and geometric parameters and reveals a defect-type structure. Site-occupancy refinements indicate an Eu deficiency on the A site coupled with O defects on one of the two O-atom positions. The crystallochemical formula of the investigated sample may thus be written as A(0.032Eu0.968)BScO2.952

Kahlenberg, V.

Maier, D.

Veličkov, B.

Repositorium für Naturwissenschaften und Technik

Redetermination of EuScO3Volker Kahlenberg,a Dirk Maierb and Boža Veličkovb*aUniversity of Innsbruck, Institute for Mineralogy and Petrography, Innrain 52, 6020Innsbruck, Austria, and bLeibniz-Institute for Crystal Growth, Max-Born-Strasse 2,12489 Berlin, GermanyCorrespondence e-mail: Velickov@ikz-berlin.deReceived 19 December 2008; accepted 12 January 2009Key indicators: single-crystal X-ray study; T = 293 K; mean (Sc–O) = 0.002 Å;disorder in main residue; R factor = 0.021; wR factor = 0.051; data-to-parameterratio = 11.7.Single crystals of europium(III) scandate(III), with idealformula EuScO3, were grown from the melt using the micro-pulling-down method. The title compound crystallizes in anorthorhombic distorted perovskite-type structure, where Euoccupies the eightfold coordinated A sites (site symmetry m)and Sc resides on the centres of corner-sharing [ScO6]octahedra (B sites with site symmetry 1). The structure ofEuScO3 has been reported previously based on powderdiffraction data [Liferovich & Mitchell (2004). J. Solid StateChem. 177, 2188–2197]. The results of the current redetermi-nation based on single-crystal diffraction data shows animprovement in the precision of the structral and geometricparameters and reveals a defect-type structure. Site-occu-pancy refinements indicate an Eu deficiency on the A sitecoupled with O defects on one of the two O-atom positions.The crystallochemical formula of the investigated sample maythus be written as A(&0.032Eu0.968)BScO2.952.Related literatureDetails of the synthesis are described by Maier et al. (2007).Rietveld refinements on powders of LnScO3 with Ln = La3+ toHo3+ are reported by Liferovich & Mitchell (2004). The crystalstructures of the Dy, Gd, Sm and Nd members refined fromsingle-crystal diffraction data have been recently provided byVeličkov et al. (2007). The crystal structure of the isotypicTbScO3 is described by Veličkov et al. (2008). Specificgeometrical parameters have been calculated by means of theatomic coordinates following the concept of Zhao et al. (1993).ExperimentalCrystal dataEu0.968ScO2.952Mr = 239.24Orthorhombic, Pnmaa = 5.7554 (7) Åb = 7.9487 (10) Åc = 5.5087 (6) ÅV = 252.01 (5) Å3Z = 4Mo K radiation = 26.28 mm1T = 293 (2) K0.14  0.12  0.02 mmData collectionStoe IPDS-2 diffractometerAbsorption correction: analytical(Alcock, 1970)Tmin = 0.139, Tmax = 0.3972168 measured reflections362 independent reflections345 reflections with I > 2(I)Rint = 0.055RefinementR[F 2 > 2(F 2)] = 0.021wR(F 2) = 0.051S = 1.27362 reflections31 parameters1 restraintmax = 1.40 e Å3min = 0.84 e Å3Table 1Selected bond lengths (Å).Eu1—O1i 2.276 (5)Eu1—O2ii 2.304 (3)Eu1—O1iii 2.375 (5)Eu1—O2iv 2.611 (3)Eu1—O2v 2.845 (3)Sc2—O2ii 2.094 (3)Sc2—O2vi 2.107 (3)Sc2—O1vii 2.1108 (16)Symmetry codes: (i) x 12; y;zþ12; (ii) x;yþ 1;zþ 1; (iii) x; y; z 1; (iv)x þ 12; y12; z12; (v) x; y 1; z 1; (vi)xþ12;yþ 1; z12; (vii) x12; y;zþ32.Data collection: X-AREA (Stoe & Cie, 2006); cell refinement: X-AREA; data reduction: X-RED (Stoe & Cie, 2006); program(s) usedto solve structure: SHELXS97 (Sheldrick, 2008); program(s) used torefine structure: SHELXL97 (Sheldrick, 2008); molecular graphics:ATOMS for Windows (Dowty, 2004); software used to preparematerial for publication: SHELXL97.Supplementary data and figures for this paper are available from theIUCr electronic archives (Reference: WM2214).ReferencesAlcock, N. W. (1970). Crystallographic Computing, edited by F. R. Ahmed, S.R. Hall & C. P. Huber, p. 271. Copenhagen: Munksgaard.Dowty, E. (2004). ATOMS for Windows. Shape Software, Kingsport,Tennessee, USA.Liferovich, R. P. & Mitchell, R. H. (2004). J. Solid State Chem. 177, 2188–2197.Maier, D., Rhede, D., Bertram, R., Klimm, D. & Fornari, R. (2007). Opt. Mater.30, 11–14.Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.Stoe & Cie (2006). X-AREA and X-RED. Stoe & Cie, Darmstadt, Germany.Veličkov, B., Kahlenberg, V., Bertram, R. & Bernhagen, M. (2007). Z.Kristallogr. 222, 466–473.Veličkov, B., Kahlenberg, V., Bertram, R. & Uecker, R. (2008). Acta Cryst.E64, i79.Zhao, Y., Weidner, D. J., Parise, J. B. & Cox, D. E. (1993). Phys. Earth Planet.Inter., 76, 1–16.inorganic compoundsi8 Kahlenberg et al. doi:10.1107/S1600536809001433 Acta Cryst. (2009). E65, i8Acta Crystallographica Section EStructure ReportsOnlineISSN 1600-5368supporting informationsup-1Acta Cryst. (2009). E65, i8    supporting informationActa Cryst. (2009). E65, i8    [doi:10.1107/S1600536809001433]Redetermination of EuScO3Volker Kahlenberg, Dirk Maier and Boža VeličkovS1. Comment Liferovich & Mitchell (2004) studied the crystal structure of lanthanoid scandates, including EuScO3, by Rietveld analysis from powder diffraction data. Crystallographic data of DyScO3, GdScO3, SmScO3 and NdScO3 obtained from single crystals were recently reported by Veličkov et al. (2007), and for TbScO3 by Veličkov et al. (2008). Based on these results it was possible to resolve disagreements concerning some structural characteristics and their dependence on the Ln-substitution. Whereas Liferovich & Mitchell (2004) observed no obvious continuous evolution, Veličkov et al. (2007) were able to show that the geometry and the distortion of the sites are linearly coupled with the size of the lanthanoid in the series from DyScO3 to NdScO3. With the structural refinement based on diffraction data collected from single crystalline EuScO3, the present results provide further data for this series.The orthorhombic distorted perovskite structure for EuScO3 (Fig. 1) is confirmed from our refinements. Whereas the lattice parameters for EuScO3 compare well with the data of Liferovich & Mitchell (2004), the fractional atomic coordinates show deviations of up to 0.006, resulting in slightly different geometrical parameters. The A-site is occupied by Eu in an eightfold coordination and has an average bond length of [8]<A—O> = 2.521 Å with a polyhedral bond length distortion of AΔ8 = 7.98×10-3 (Δn = 1/n Σ{(ri-r)/r2). The B-site shows bond lengths typical for octahedrally coordinated scandium (<B—O> = 2.104 Å) and is rather distorted with BΔ6 = 0.015×10-3 and a bond angle variance of δ = 2.61°. The tilting of the corner sharing octahedra calculated after Zhao et al. (1993) are θ = 19.70° in [110] and Ø = 12.66° in [001] directions. From our data we can establish linear trends for the crystallochemical parameters from DyScO3 to NdScO3 depending on the Ln-substitution.S2. Experimental An EuScO3 fiber was grown using a micro-pulling-down apparatus with induction heating (Maier et al., 2007). The starting material was prepared from 4 N Eu2O3 and Sc2O3 powders by grinding a total weight of 5 g in a plastic mortar and pressing the mixture into pellets. An 5 ml iridium crucible with 500 mg of the starting material was placed on an iridium after-heater and heated by the inductor coil of a 10 kW rf Generator. The crucible after-heater arrangement was surrounded by a zirconia fiber tube and a high-purity alumina tube for thermal insulation. The experiments were carried out in a vacuum-tight steel chamber. It was evacuated before each experiment to 5 x10-3 mbar and filled with 5 N argon gas. Subsequently, a constant flow of about 900 ml/min was kept. During growth the height of the molten zone and consequently the diameter of the fiber (~1 mm) was carefully controlled by manually increasing or decreasing the rf-power. Several starting compositions with different Eu to Sc ratios were tested, resulting in the optimal batch with 47.5 mol% Eu2O3 and 52.5 mol% Sc2O3.The grown single-crystal was colourless. A part of the single-crystal fiber was crushed and the irregular shaped fragments were screened using a polarizing light microscope to find a sample of good optical quality for the diffraction experiments.supporting informationsup-2Acta Cryst. (2009). E65, i8    S3. Refinement Site occupation refinements indicated deviations from full occupancy on the Eu1 (A-site) and the O2 sites. For the final refinement cycle a constraint ensuring charge neutrality was included. The crystallochemical formula of the investigated sample can thus be written as A(□0.032Eu0.968)BScO2.952. The highest peak and deepest hole of the difference Fourier map are located 0.84 Å and 1.42 Å away from the Eu1 position. In contrast to the previous Rietveld refinement, where the Pbnm setting of space group no. 62 was chosen, the standard setting Pnma was used for the present redetermination.Figure 1The orthorhombic perovskite structure of EuScO3 is characterized by a tilted corner sharing ScO6 framework incorporating the 8-fold coordinated Eu sites. The ScO6 octahedra are yellow, the Eu atoms are given in grey and the O atoms are presented in red. supporting informationsup-3Acta Cryst. (2009). E65, i8    Figure 2Projection of the EuScO3 structure along [010], showing the Eu atoms and the Sc coordination with displacement ellipsoids at the 80% probability level. europium(III) scandate(III) Crystal data Eu0.968ScO2.952Mr = 239.24Orthorhombic, PnmaHall symbol: -P 2ac 2na = 5.7554 (7) Åb = 7.9487 (10) Åc = 5.5087 (6) ÅV = 252.01 (5) Å3Z = 4F(000) = 422.4Dx = 6.307 Mg m−3Mo Kα radiation, λ = 0.71073 ÅCell parameters from 2218 reflectionsθ = 2.6–29.2°µ = 26.28 mm−1T = 293 KPlaty fragment, colourless0.14 × 0.12 × 0.02 mmData collection Stoe IPDS-2 diffractometerRadiation source: fine-focus sealed tubeGraphite monochromatorDetector resolution: 6.67 pixels mm-1ω scansAbsorption correction: analytical (Alcock, 1970)Tmin = 0.139, Tmax = 0.3972168 measured reflections362 independent reflections345 reflections with I > 2σ(I)Rint = 0.055supporting informationsup-4Acta Cryst. (2009). E65, i8    θmax = 29.1°, θmin = 4.5°h = −7→7k = −10→9l = −7→7Refinement Refinement on F2Least-squares matrix: fullR[F2 > 2σ(F2)] = 0.021wR(F2) = 0.051S = 1.27362 reflections31 parameters1 restraintPrimary atom site location: structure-invariant direct methodsSecondary atom site location: difference Fourier mapw = 1/[σ2(Fo2) + (0.0211P)2 + 0.9412P] where P = (Fo2 + 2Fc2)/3(Δ/σ)max = 0.011Δρmax = 1.40 e Å−3Δρmin = −0.84 e Å−3Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4Extinction coefficient: 0.113 (5)Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) x y z Uiso*/Ueq Occ. (<1)Eu1 0.05854 (5) 0.25 0.01589 (6) 0.0090 (2) 0.9677 (13)Sc2 0 0 0.5 0.0078 (3)O1 0.4506 (8) 0.25 0.8815 (9) 0.0111 (9)O2 0.1954 (6) 0.9378 (4) 0.8078 (6) 0.0112 (7) 0.9758 (10)Atomic displacement parameters (Å2) U11 U22 U33 U12 U13 U23Eu1 0.0070 (3) 0.0102 (3) 0.0098 (3) 0 0.00051 (11) 0Sc2 0.0064 (6) 0.0079 (6) 0.0090 (6) 0.0006 (6) 0.0000 (3) 0.0000 (3)O1 0.011 (2) 0.008 (2) 0.014 (2) 0 −0.0025 (17) 0O2 0.0096 (16) 0.0121 (17) 0.0119 (14) −0.0019 (12) −0.0018 (11) 0.0005 (12)Geometric parameters (Å, º) Eu1—O1i 2.276 (5) Sc2—O2ii 2.094 (3)Eu1—O2ii 2.304 (3) Sc2—O2xii 2.094 (3)Eu1—O2iii 2.304 (3) Sc2—O2vi 2.107 (3)Eu1—O1iv 2.375 (5) Sc2—O2xiii 2.107 (3)Eu1—O2v 2.611 (3) Sc2—O1xiv 2.1108 (16)Eu1—O2vi 2.611 (3) Sc2—O1x 2.1108 (16)Eu1—O2vii 2.845 (3) Sc2—Eu1xv 3.2268 (4)Eu1—O2viii 2.845 (3) Sc2—Eu1i 3.2268 (4)supporting informationsup-5Acta Cryst. (2009). E65, i8    Eu1—Sc2ix 3.2268 (4) Sc2—Eu1xvi 3.3428 (4)Eu1—Sc2x 3.2268 (4) Sc2—Eu1xvii 3.4841 (4)Eu1—Sc2xi 3.3428 (4) Sc2—Eu1xviii 3.4841 (4)Eu1—Sc2 3.3428 (4)O1i—Eu1—O2ii 103.43 (12) O2xii—Sc2—O2vi 90.88 (6)O1i—Eu1—O2iii 103.43 (12) O2ii—Sc2—O2xiii 90.88 (6)O2ii—Eu1—O2iii 80.77 (17) O2xii—Sc2—O2xiii 89.12 (6)O1i—Eu1—O1iv 87.69 (11) O2vi—Sc2—O2xiii 180O2ii—Eu1—O1iv 137.24 (9) O2ii—Sc2—O1xiv 87.46 (16)O2iii—Eu1—O1iv 137.24 (9) O2xii—Sc2—O1xiv 92.54 (16)O1i—Eu1—O2v 137.77 (9) O2vi—Sc2—O1xiv 92.67 (15)O2ii—Eu1—O2v 117.06 (6) O2xiii—Sc2—O1xiv 87.33 (15)O2iii—Eu1—O2v 73.38 (8) O2ii—Sc2—O1x 92.54 (16)O1iv—Eu1—O2v 71.14 (12) O2xii—Sc2—O1x 87.46 (16)O1i—Eu1—O2vi 137.77 (9) O2vi—Sc2—O1x 87.33 (15)O2ii—Eu1—O2vi 73.38 (8) O2xiii—Sc2—O1x 92.67 (15)O2iii—Eu1—O2vi 117.06 (6) O1xiv—Sc2—O1x 180O1iv—Eu1—O2vi 71.14 (12) Sc2xix—O1—Sc2xv 140.6 (2)O2v—Eu1—O2vi 69.74 (15) Sc2xix—O1—Eu1xx 105.10 (13)O1i—Eu1—O2vii 71.82 (8) Sc2xv—O1—Eu1xx 105.10 (13)O2ii—Eu1—O2vii 77.31 (12) Sc2xix—O1—Eu1xviii 91.82 (14)O2iii—Eu1—O2vii 155.61 (9) Sc2xv—O1—Eu1xviii 91.82 (14)O1iv—Eu1—O2vii 67.12 (8) Eu1xx—O1—Eu1xviii 124.0 (2)O2v—Eu1—O2vii 126.63 (6) Sc2xxi—O2—Sc2xxii 143.00 (18)O2vi—Eu1—O2vii 66.38 (5) Sc2xxi—O2—Eu1ii 98.83 (13)O1i—Eu1—O2viii 71.82 (8) Sc2xxii—O2—Eu1ii 117.90 (14)O2ii—Eu1—O2viii 155.61 (9) Sc2xxi—O2—Eu1xxii 85.85 (11)O2iii—Eu1—O2viii 77.31 (12) Sc2xxii—O2—Eu1xxii 89.57 (12)O1iv—Eu1—O2viii 67.12 (8) Eu1ii—O2—Eu1xxii 103.48 (13)O2v—Eu1—O2viii 66.38 (5) Sc2xxi—O2—Eu1xxiii 88.37 (12)O2vi—Eu1—O2viii 126.63 (6) Sc2xxii—O2—Eu1xxiii 79.82 (10)O2vii—Eu1—O2viii 121.45 (13) Eu1ii—O2—Eu1xxiii 102.69 (12)O2ii—Sc2—O2xii 180 Eu1xxii—O2—Eu1xxiii 153.77 (14)O2ii—Sc2—O2vi 89.12 (6)Symmetry codes: (i) x−1/2, y, −z+1/2; (ii) −x, −y+1, −z+1; (iii) −x, y−1/2, −z+1; (iv) x, y, z−1; (v) −x+1/2, y−1/2, z−1/2; (vi) −x+1/2, −y+1, z−1/2; (vii) x, y−1, z−1; (viii) x, −y+3/2, z−1; (ix) x+1/2, −y+1/2, −z+1/2; (x) −x+1/2, −y, z−1/2; (xi) −x, y+1/2, −z+1; (xii) x, y−1, z; (xiii) x−1/2, y−1, −z+3/2; (xiv) x−1/2, y, −z+3/2; (xv) −x+1/2, −y, z+1/2; (xvi) −x, −y, −z+1; (xvii) −x, −y, −z; (xviii) x, y, z+1; (xix) x+1/2, −y+1/2, −z+3/2; (xx) x+1/2, y, −z+1/2; (xxi) x, y+1, z; (xxii) −x+1/2, −y+1, z+1/2; (xxiii) x, y+1, z+1.

ATOMS for Windows. Shape Software,

Crystallographic Computing, edited by

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) x y z Uiso*/Ueq Occ.

From our data we can establish linear trends for the crystallochemical parameters from DyScO3 to NdScO3 depending on the Ln-substitution. Experimental An EuScO3 fiber was grown using a micro-pulling-down apparatus with induction heating (Maier et al.,

Phys. Earth Planet. Inter., 76, 1–16. inorganic compounds i8 Kahlenberg et al. doi:10.1107/S1600536809001433 Acta Cryst.

Projection of the EuScO3 structure along [010], showing the Eu atoms and the Sc coordination with displacement ellipsoids at the 80% probability level. europium(III) scandate(III) Crystal data

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Redetermination of EuScO3

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