Trineodymium(III) penta­iron(III) dodeca­oxide, Nd₃Fe₅O₁₂

Abstract

The title compound, Nd₃Fe₅O₁₂ (NdIG), has an iron garnet structure. One of the Fe atoms is coordinated by six O atoms in a slightly distorted octa­hedral geometry and has site symmetry. The other Fe atom is coordinated by four O atoms in a slightly distorted tetra­hedral geometry and has site symmetry. The FeO₆ octa­hedron and FeO₄ tetra­hedron are linked together by corners. The Nd atom is coordinated by eight O atoms in a distorted dodeca­hedral geometry and has 222 site symmetry. The O atoms occupy general positions.

Related literature

The title compound is isotypic with the Ia d form of Y₃Fe₅O₁₂ (YIG), see: Bonnet et al. (1975 ▶). For crystal growth from low-temperature liquid-phase epitaxy, see: Fratello et al. (1986 ▶). X-ray intensities were measured avoiding multiple diffraction, see: Takenaka et al. (2008 ▶). For details of the full-matrix least-squares program QNTAO, see: Tanaka et al. (2008 ▶). For the anisotropic extinction refinement, see: Becker & Coppens (1975 ▶).

Experimental

Crystal data

• Nd₃Fe₅O₁₂

• M _r = 903.97

• Cubic,

• a = 12.6128 (2) Å

• V = 2006.48 (6) ų

• Z = 8

• Synchrotron radiation

• λ = 0.67171 Å

• μ = 18.30 mm⁻¹

• T = 298 K

• 0.025 mm (radius)

Data collection

• Rigaku AFC four-circle diffractometer

• Absorption correction: spherical [transmission coefficients for spheres tabulated in International Tables C (1992 ▶), Table 6.3.3.3, were interpolated with Lagrange’s method (four point interpolation; Yamauchi et al., 1965 ▶)] T _min = 0.502, T _max = 0.527

• 6653 measured reflections

• 1159 independent reflections

• 1159 reflections with F > 3σ(F)

• R _int = 0.017

Refinement

• R[F ² > 2σ(F ²)] = 0.016

• wR(F ²) = 0.018

• S = 1.42

• 6653 reflections

• 23 parameters

• Δρ_max = 1.61 e Å⁻³

• Δρ_min = −1.75 e Å⁻³

Data collection: AFC-5, specially designed for PF-BL14A (Rigaku Corporation, 1984 ▶) and IUANGLE (Tanaka et al., 1994 ▶).; cell refinement: RSLC-3 (Sakurai & Kobayashi, 1979 ▶); data reduction: RDEDIT (Tanaka, 2008 ▶); program(s) used to solve structure: QNTAO (Tanaka et al., 2008 ▶); program(s) used to refine structure: QNTAO (Tanaka et al., 2008 ▶); molecular graphics: ATOMS for Windows (Dowty, 2000 ▶); software used to prepare material for publication: RDEDIT.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected geometric parameters (Å, °).

Nd1—O1	2.41820 (10)
Nd1—O1i	2.52960 (10)
Fe1—O1	2.03300 (10)
Fe2—O1ii	1.87550 (10)

O1—Fe1—O1i	85.59 (1)
O1ii—Fe2—O1iii	114.47 (1)
O1ii—Fe2—O1iv	99.87 (1)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .

supplementary crystallographic information

Comment

The title compound, Nd₃Fe₅O₁₂ (NdIG), was difficult to be grown. It was grown by the low-temperature-liquid-phase epitaxy for the first time by Fratello et al. (1986). Though the crystal structure was assumed as iron-garnet-type structure by lattice constant and extinction rule, the complete structure was not determined. In this paper, we determine the O atom position and the complete structure by the full matrix least-squares program QNTAO. Since the R-factor is small and the residual density has no significant peaks where no atoms exists, the structure was finally determined to be iron-garnet structure. It is isotypic with the Ia3d form of Y₃Fe₅O₁₂ (YIG). (Bonnet et al., 1975). The Nd atom is coordinated by eight oxygen atoms. It forms a distorted dodecahedron. There are two Fe site symmetries. One of the Fe atom is coordinated by six oxygen atoms with site symmetry 3. It forms a slightly distorted octahedron. The other Fe atom is coordinated by four oxygen atoms, site symmetry 4. It forms a slightly distorted tetrahedron. FeO₆ octahedron and FeO₄ tetrahedron are linked together by corners. The structure of NdIG is drawn in Fig.1. And displacement ellipsoids of NdO₈ is drawn in Fig.2.

Experimental

Single crystals of neodymium iron garnet were prepared by low temperature liquid phase epitaxy on Sm₃(ScGa)₅O₁₂ seeds with lattice parameters near the projected values for NdIG.

Refinement

The Becker–Coppens type 1 Gaussian anisotropic extinction parameters were employed (× 10^-4 seconds). z11 = 10.2 (5), z22 = 10 (2), z33 = 12 (2), z12 = 1(1), z13 = -0.5 (7), z23 = -1(1). X-ray intensities were measured avoiding multiple diffraction. (Takenaka et al., 2008).

Figures

Fig. 1.

The structure of Nd3Fe5O12. Small red and large green spheres represent O and Nd atoms, respectively. Purple octahedron and blue tetrahedron represent FeO6 and FeO4 units, respectively.

Fig. 2.

View of NdO8 with displacement ellipsoids at the 90% probability level. Green and red ellipsoids represent Nd and O atoms, in Fig.1.

Crystal data

Nd3Fe5O12	Dx = 5.985 Mg m−3
Mr = 903.97	Synchrotron radiation, λ = 0.67171 Å
Cubic, Ia3d	Cell parameters from 24 reflections
Hall symbol: -I 4bd 2c 3	θ = 35.7–42.4°
a = 12.6128 (2) Å	µ = 18.30 mm−1
V = 2006.48 (6) Å3	T = 298 K
Z = 8	Sphere, black
F(000) = 3248	0.03 mm (radius)

Data collection

Rigaku AFC four-circle diffractometer	1159 independent reflections
Si 111	1159 reflections with F > 3σ(F)
Detector resolution: 1.25×1.25 degrees pixels mm-1	Rint = 0.017
ω/2θ scans	θmax = 53.9°, θmin = 3.7°
Absorption correction: for a sphere Transmission coefficients for spheres tabulated in International Tables C (1992\bbr00), Table 6.3.3.3, were interpolated with Lagrange's method (four point interpolation; Yamauchi et al., 1965).	h = −8→30
Tmin = 0.502, Tmax = 0.527	k = −8→30
6653 measured reflections	l = −8→30

Refinement

Refinement on F	Primary atom site location: isomorphous structure methods
Least-squares matrix: full	Weighting scheme based on measured s.u.'s
R[F2 > 2σ(F2)] = 0.016	(Δ/σ)max = 0.003
wR(F2) = 0.018	Δρmax = 1.61 e Å−3
S = 1.42	Δρmin = −1.75 e Å−3
6653 reflections	Extinction correction: (B-C type 1 Gaussian anisotropic; Becker & Coppens (1975)
23 parameters	Extinction coefficient: 0.308 (5)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Nd1	0.125000	0.000000	0.250000	0.00557 (1)
Fe1	0.000000	0.000000	0.000000	0.00501 (1)
Fe2	0.375000	0.000000	0.250000	0.00564 (1)
O1	−0.029295 (2)	0.053092 (2)	0.149342 (2)	0.00762 (5)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Nd1	0.00421 (1)	0.00525 (1)	0.00525 (1)	0	0	0.00121 (1)
Fe1	0.00501 (2)	0.00501 (2)	0.00501 (2)	−0.00024 (2)	−0.00024 (2)	−0.00024 (2)
Fe2	0.00442 (3)	0.00625 (2)	0.00625 (2)	0	0	0
O1	0.00791 (8)	0.00880 (9)	0.00614 (7)	−0.00027 (7)	0.00102 (6)	0.00041 (7)

Geometric parameters (Å, °)

Nd1—O1	2.41820 (10)	Fe1—O1i	2.03300 (10)
Nd1—O1i	2.52960 (10)	Fe1—O1viii	2.03300 (10)
Nd1—O1ii	2.41820 (10)	Fe1—O1ix	2.03300 (10)
Nd1—O1iii	2.52960 (10)	Fe1—O1x	2.03300 (10)
Nd1—O1iv	2.41820 (10)	Fe1—O1xi	2.03300 (10)
Nd1—O1v	2.52960 (10)	Fe2—O1xii	1.87550 (10)
Nd1—O1vi	2.41820 (10)	Fe2—O1iv	1.87550 (10)
Nd1—O1vii	2.52960 (10)	Fe2—O1xiii	1.87550 (10)
Fe1—O1	2.03300 (10)	Fe2—O1vi	1.87550 (10)
O1—Nd1—O1i	67.83 (1)	O1—Fe1—O1viii	85.59 (1)
O1—Nd1—O1ii	72.82 (1)	O1—Fe1—O1ix	180.00
O1—Nd1—O1iii	124.94 (1)	O1—Fe1—O1x	94.41 (1)
O1—Nd1—O1iv	110.91 (1)	O1—Fe1—O1xi	94.41 (1)
O1—Nd1—O1v	72.97 (1)	O1xii—Fe2—O1vi	114.47 (1)
O1—Nd1—O1vi	159.79 (1)	O1xii—Fe2—O1iv	114.47 (1)
O1—Nd1—O1vii	95.60 (1)	O1xii—Fe2—O1xiii	99.87 (1)
O1—Fe1—O1i	85.59 (1)

Symmetry codes: (i) z, x, y; (ii) x, −y, −z+1/2; (iii) z, −x, −y+1/2; (iv) −x+1/4, −z+1/4, −y+1/4; (v) −z+1/4, −y+1/4, −x+1/4; (vi) −x+1/4, z−1/4, y+1/4; (vii) −z+1/4, y−1/4, x+1/4; (viii) y, z, x; (ix) −x, −y, −z; (x) −z, −x, −y; (xi) −y, −z, −x; (xii) x+1/2, y, −z+1/2; (xiii) x+1/2, −y, z.