Tripraseodymium penta-iron(III) dodeca-oxide, Pr(3)Fe(5)O(12): a synchrotron radiation study.

The title compound, penta-iron tripraseodymium dodeca-oxide (PrIG), has an iron garnet structure. There are two Fe site symmetries. One of the Fe atoms is coordinated by six O atoms, forming a slightly distorted octa-hedron, and has site symmetry. The other Fe atom is coordinated by four O atoms, forming a slightly distorted tetra-hedron, and has site symmetry. FeO(6) octa-hedra and FeO(4) tetra-hedra are linked together by corners. The Pr atom is coordinated by eight O atoms, forming a distorted dodeca-hedron, and has 222 site symmetry. The O atoms occupy the general positions.

Related literature

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

Experimental

Crystal data

Pr3Fe5O12

M = 893.98

Cubic,

a = 12.6302 (3) Å

V = 2014.79 (8) Å3

Z = 8

Synchrotron radiation

λ = 0.67171 Å

μ = 17.41 mm−1

T = 298 K

0.035 mm (radius)

Data collection

Rigaku AFC four-circle diffractometer

Absorption correction: for a sphere [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 = 0.413, T max = 0.441

9351 measured reflections

1728 independent reflections

1728 reflections with F > 3σ(F)

R int = 0.016

Refinement

R[F 2 > 2σ(F 2)] = 0.019

wR(F 2) = 0.021

S = 1.06

9351 reflections

17 parameters

Δρmax = 2.52 e Å−3

Δρmin = −3.16 e Å−3

Data collection: AFC-5, specially designed for PF-BL14A (Rigaku, 1984 ▶) and IUANGLE (Tanaka et al., 1994 ▶); cell refinement: RSLC-3 UNICS system (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; molecular graphics: ATOMS for Windows (Dowty, 2000 ▶); software used to prepare material for publication: RDEDIT.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809038100/br2121sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809038100/br2121Isup2.hkl

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

Pr3Fe5O12	Dx = 5.894 Mg m−3
Mr = 893.98	Synchrotron radiation, λ = 0.67171 Å
Cubic, Ia3d	Cell parameters from 9 reflections
Hall symbol: -I 4bd 2c 3	θ = 17.5–52.3°
a = 12.6302 (3) Å	µ = 17.41 mm−1
V = 2014.79 (8) Å3	T = 298 K
Z = 8	Sphere, black
F(000) = 3224	0.04 mm (radius)

Rigaku AFC four-circle diffractometer	1728 independent reflections
Si 111	1728 reflections with F > 3σ(F)
Detector resolution: 1.25 × 1.25° pixels mm-1	Rint = 0.016
ω/2θ scans	θmax = 68.3°, θmin = 3.7°
Absorption correction: for a sphere [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)]	h = −9→34
Tmin = 0.413, Tmax = 0.441	k = −9→32
9351 measured reflections	l = −9→34

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)] = 0.019	(Δ/σ)max = 0.003
wR(F2) = 0.021	Δρmax = 2.52 e Å−3
S = 1.06	Δρmin = −3.16 e Å−3
9351 reflections	Extinction correction: B–C type 1 Gaussian isotropic (Becker & Coppens, 1975)
17 parameters	Extinction coefficient: 0.255 (5)

	x	y	z	Uiso*/Ueq
Pr1	0.125000	0.000000	0.250000	0.00531 (1)
Fe1	0.000000	0.000000	0.000000	0.00512 (1)
Fe2	0.375000	0.000000	0.250000	0.00533 (1)
O1	−0.029622 (2)	0.052553 (2)	0.149166 (2)	0.00711 (5)

	U11	U22	U33	U12	U13	U23
Pr1	0.00406 (2)	0.00594 (2)	0.00594 (2)	0	0	0.00111 (1)
Fe1	0.00512 (2)	0.00512 (2)	0.00512 (2)	−0.00023 (1)	−0.00023 (1)	−0.00023 (1)
Fe2	0.00411 (3)	0.00594 (2)	0.00594 (2)	0	0	0
O1	0.00718 (8)	0.00829 (8)	0.00587 (7)	−0.00004 (6)	0.00080 (6)	0.00038 (6)

Pr1—O1	2.42410 (10)	Fe1—O1i	2.03220 (10)
Pr1—O1i	2.54010 (10)	Fe1—O1viii	2.03220 (10)
Pr1—O1ii	2.42410 (10)	Fe1—O1ix	2.03220 (10)
Pr1—O1iii	2.54010 (10)	Fe1—O1x	2.03220 (10)
Pr1—O1iv	2.42410 (10)	Fe1—O1xi	2.03220 (10)
Pr1—O1v	2.54010 (10)	Fe2—O1xii	1.87450 (10)
Pr1—O1vi	2.42410 (10)	Fe2—O1iv	1.87450 (10)
Pr1—O1vii	2.54010 (10)	Fe2—O1xiii	1.87450 (10)
Fe1—O1	2.03220 (10)	Fe2—O1vi	1.87450 (10)
O1—Pr1—O1i	67.75 (1)	O1—Fe1—O1viii	85.87 (1)
O1—Pr1—O1ii	72.66 (1)	O1—Fe1—O1ix	180.00
O1—Pr1—O1iii	124.91 (1)	O1—Fe1—O1x	94.13 (1)
O1—Pr1—O1iv	111.18 (1)	O1—Fe1—O1xi	94.13 (1)
O1—Pr1—O1v	73.25 (1)	O1xii—Fe2—O1vi	114.39 (1)
O1—Pr1—O1vi	159.51 (1)	O1xii—Fe2—O1iv	114.39 (1)
O1—Pr1—O1vii	95.43 (1)	O1xii—Fe2—O1xiii	100.02 (1)
O1—Fe1—O1i	85.87 (1)

Pr1—O1	2.42410 (10)
Pr1—O1i	2.54010 (10)
Fe1—O1	2.03220 (10)
Fe2—O1ii	1.87450 (10)

O1—Fe1—O1i	85.87 (1)
O1ii—Fe2—O1iii	114.39 (1)
O1ii—Fe2—O1iv	100.02 (1)

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