Literature DB >> 21581742

Redetermination of EuScO(3).

Volker Kahlenberg, Dirk Maier, Boža Veličkov.

Abstract

Single crystals of europium(III) scandate(III), with ideal formula EuScO(3), 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 [ScO(6)] octa-hedra (B sites with site symmetry ). The structure of EuScO(3) 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)(□(0.032)Eu(0.968))(B)ScO(2.952).

Entities: Chemical Disease Gene

Year: 2009 PMID： 21581742 PMCID： PMC2968298 DOI： 10.1107/S1600536809001433

Source DB: PubMed Journal: Acta Crystallogr Sect E Struct Rep Online ISSN： 1600-5368

Related literature

Details of the synthesis are described by Maier et al. (2007 ▶). Rietveld refinements on powders of LnScO3 with Ln = La3+ to Ho3+ are reported by Liferovich & Mitchell (2004 ▶). The crystal structures of the Dy, Gd, Sm and Nd members refined from single-crystal diffraction data have been recently provided by Veličkov et al. (2007 ▶). The crystal structure of the isotypic TbScO3 is described by Veličkov et al. (2008 ▶). Specific geometrical parameters have been calculated by means of the atomic coordinates following the concept of Zhao et al. (1993 ▶).

Experimental

Crystal data

Eu0.968ScO2.952 M = 239.24 Orthorhombic, a = 5.7554 (7) Å b = 7.9487 (10) Å c = 5.5087 (6) Å V = 252.01 (5) Å3 Z = 4 Mo Kα radiation μ = 26.28 mm−1 T = 293 (2) K 0.14 × 0.12 × 0.02 mm

Data collection

Stoe IPDS-2 diffractometer Absorption correction: analytical (Alcock, 1970 ▶) T min = 0.139, T max = 0.397 2168 measured reflections 362 independent reflections 345 reflections with I > 2σ(I) R int = 0.055

Refinement

R[F 2 > 2σ(F 2)] = 0.021 wR(F 2) = 0.051 S = 1.27 362 reflections 31 parameters 1 restraint Δρmax = 1.40 e Å−3 Δρmin = −0.84 e Å−3 Data collection: X-AREA (Stoe & Cie, 2006 ▶); cell refinement: X-AREA; data reduction: X-RED (Stoe & Cie, 2006 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ATOMS for Windows (Dowty, 2004 ▶); software used to prepare material for publication: SHELXL97. Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809001433/wm2214sup1.cif Structure factors: contains datablocks I. DOI: 10.1107/S1600536809001433/wm2214Isup2.hkl Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Eu_0.968ScO_2.952	F(000) = 422.4
M_r = 239.24	D_x = 6.307 Mg m⁻³
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 2218 reflections
a = 5.7554 (7) Å	θ = 2.6–29.2°
b = 7.9487 (10) Å	µ = 26.28 mm⁻¹
c = 5.5087 (6) Å	T = 293 K
V = 252.01 (5) Å³	Platy fragment, colourless
Z = 4	0.14 × 0.12 × 0.02 mm

Stoe IPDS-2 diffractometer	362 independent reflections
Radiation source: fine-focus sealed tube	345 reflections with I > 2σ(I)
graphite	R_int = 0.055
Detector resolution: 6.67 pixels mm^-1	θ_max = 29.1°, θ_min = 4.5°
ω scans	h = −7→7
Absorption correction: analytical (Alcock, 1970)	k = −10→9
T_min = 0.139, T_max = 0.397	l = −7→7
2168 measured reflections

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.021	w = 1/[σ²(F_o²) + (0.0211P)² + 0.9412P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.051	(Δ/σ)_max = 0.011
S = 1.27	Δρ_max = 1.40 e Å⁻³
362 reflections	Δρ_min = −0.84 e Å⁻³
31 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
1 restraint	Extinction coefficient: 0.113 (5)

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.

	x	y	z	U_iso*/U_eq	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)

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Eu1	0.0070 (3)	0.0102 (3)	0.0098 (3)	0	0.00051 (11)	0
Sc2	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)	0
O2	0.0096 (16)	0.0121 (17)	0.0119 (14)	−0.0019 (12)	−0.0018 (11)	0.0005 (12)

Eu1—O1ⁱ	2.276 (5)	Sc2—O2ⁱⁱ	2.094 (3)
Eu1—O2ⁱⁱ	2.304 (3)	Sc2—O2^xii	2.094 (3)
Eu1—O2ⁱⁱⁱ	2.304 (3)	Sc2—O2^vi	2.107 (3)
Eu1—O1^iv	2.375 (5)	Sc2—O2^xiii	2.107 (3)
Eu1—O2^v	2.611 (3)	Sc2—O1^xiv	2.1108 (16)
Eu1—O2^vi	2.611 (3)	Sc2—O1^x	2.1108 (16)
Eu1—O2^vii	2.845 (3)	Sc2—Eu1^xv	3.2268 (4)
Eu1—O2^viii	2.845 (3)	Sc2—Eu1ⁱ	3.2268 (4)
Eu1—Sc2^ix	3.2268 (4)	Sc2—Eu1^xvi	3.3428 (4)
Eu1—Sc2^x	3.2268 (4)	Sc2—Eu1^xvii	3.4841 (4)
Eu1—Sc2^xi	3.3428 (4)	Sc2—Eu1^xviii	3.4841 (4)
Eu1—Sc2	3.3428 (4)

O1ⁱ—Eu1—O2ⁱⁱ	103.43 (12)	O2^xii—Sc2—O2^vi	90.88 (6)
O1ⁱ—Eu1—O2ⁱⁱⁱ	103.43 (12)	O2ⁱⁱ—Sc2—O2^xiii	90.88 (6)
O2ⁱⁱ—Eu1—O2ⁱⁱⁱ	80.77 (17)	O2^xii—Sc2—O2^xiii	89.12 (6)
O1ⁱ—Eu1—O1^iv	87.69 (11)	O2^vi—Sc2—O2^xiii	180
O2ⁱⁱ—Eu1—O1^iv	137.24 (9)	O2ⁱⁱ—Sc2—O1^xiv	87.46 (16)
O2ⁱⁱⁱ—Eu1—O1^iv	137.24 (9)	O2^xii—Sc2—O1^xiv	92.54 (16)
O1ⁱ—Eu1—O2^v	137.77 (9)	O2^vi—Sc2—O1^xiv	92.67 (15)
O2ⁱⁱ—Eu1—O2^v	117.06 (6)	O2^xiii—Sc2—O1^xiv	87.33 (15)
O2ⁱⁱⁱ—Eu1—O2^v	73.38 (8)	O2ⁱⁱ—Sc2—O1^x	92.54 (16)
O1^iv—Eu1—O2^v	71.14 (12)	O2^xii—Sc2—O1^x	87.46 (16)
O1ⁱ—Eu1—O2^vi	137.77 (9)	O2^vi—Sc2—O1^x	87.33 (15)
O2ⁱⁱ—Eu1—O2^vi	73.38 (8)	O2^xiii—Sc2—O1^x	92.67 (15)
O2ⁱⁱⁱ—Eu1—O2^vi	117.06 (6)	O1^xiv—Sc2—O1^x	180
O1^iv—Eu1—O2^vi	71.14 (12)	Sc2^xix—O1—Sc2^xv	140.6 (2)
O2^v—Eu1—O2^vi	69.74 (15)	Sc2^xix—O1—Eu1^xx	105.10 (13)
O1ⁱ—Eu1—O2^vii	71.82 (8)	Sc2^xv—O1—Eu1^xx	105.10 (13)
O2ⁱⁱ—Eu1—O2^vii	77.31 (12)	Sc2^xix—O1—Eu1^xviii	91.82 (14)
O2ⁱⁱⁱ—Eu1—O2^vii	155.61 (9)	Sc2^xv—O1—Eu1^xviii	91.82 (14)
O1^iv—Eu1—O2^vii	67.12 (8)	Eu1^xx—O1—Eu1^xviii	124.0 (2)
O2^v—Eu1—O2^vii	126.63 (6)	Sc2^xxi—O2—Sc2^xxii	143.00 (18)
O2^vi—Eu1—O2^vii	66.38 (5)	Sc2^xxi—O2—Eu1ⁱⁱ	98.83 (13)
O1ⁱ—Eu1—O2^viii	71.82 (8)	Sc2^xxii—O2—Eu1ⁱⁱ	117.90 (14)
O2ⁱⁱ—Eu1—O2^viii	155.61 (9)	Sc2^xxi—O2—Eu1^xxii	85.85 (11)
O2ⁱⁱⁱ—Eu1—O2^viii	77.31 (12)	Sc2^xxii—O2—Eu1^xxii	89.57 (12)
O1^iv—Eu1—O2^viii	67.12 (8)	Eu1ⁱⁱ—O2—Eu1^xxii	103.48 (13)
O2^v—Eu1—O2^viii	66.38 (5)	Sc2^xxi—O2—Eu1^xxiii	88.37 (12)
O2^vi—Eu1—O2^viii	126.63 (6)	Sc2^xxii—O2—Eu1^xxiii	79.82 (10)
O2^vii—Eu1—O2^viii	121.45 (13)	Eu1ⁱⁱ—O2—Eu1^xxiii	102.69 (12)
O2ⁱⁱ—Sc2—O2^xii	180	Eu1^xxii—O2—Eu1^xxiii	153.77 (14)
O2ⁱⁱ—Sc2—O2^vi	89.12 (6)

Table 1

Selected bond lengths (Å)

Eu1—O1ⁱ	2.276 (5)
Eu1—O2ⁱⁱ	2.304 (3)
Eu1—O1ⁱⁱⁱ	2.375 (5)
Eu1—O2^iv	2.611 (3)
Eu1—O2^v	2.845 (3)
Sc2—O2ⁱⁱ	2.094 (3)
Sc2—O2^vi	2.107 (3)
Sc2—O1^vii	2.1108 (16)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) .

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1. A short history of SHELX.

Authors: George M Sheldrick
Journal: Acta Crystallogr A Date: 2007-12-21 Impact factor: 2.290

2. Redetermination of terbium scandate, revealing a defect-type perovskite derivative.

Authors: Boža Veličkov; Volker Kahlenberg; Rainer Bertram; Reinhard Uecker
Journal: Acta Crystallogr Sect E Struct Rep Online Date: 2008-10-31

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