Redetermination of Dy₃Ni from single-crystal X-ray data

Abstract

The classification of the title compound, tridysprosium nickel, into the Fe₃C (or Al₃Ni) structure type has been deduced from powder X-ray diffraction data with lattice parameters reported in a previous study [Lemaire & Paccard (1967 ▶). Bull. Soc. Fr. Mineral. Cristallogr. 40, 311–315]. The current re-investigation of Dy₃Ni based on single-crystal X-ray data revealed atomic positional parameters and anisotropic displacement parameters with high precision. The asymmetric unit consists of two Dy and one Ni atoms. One Dy atom has site symmetry .m. (Wyckoff position 4c) and is surrounded by twelve Dy and three Ni atoms. The other Dy atom (site symmetry 1, 8d) has eleven Dy and three Ni atoms as neighbours, forming a distorted Frank–Kasper polyhedron. The coordination polyhedron of the Ni atom (.m., 4c) is a tricapped trigonal prism formed by nine Dy atoms.

Related literature  

For a previous crystallographic investigation of the title compound, see: Lemaire & Paccard (1967 ▶). For the Fe₃C structure, see: Hendricks (1930 ▶), and for the Al₃Ni structure, see: Bradley & Taylor (1937 ▶). For the Dy–Ni phase diagram, see: Zheng & Wang (1982 ▶). For magnetic properties of Dy₃Ni, see: Talik et al. (1996 ▶), and for magnetic properties of Dy₃Co, see: Baranov et al. (1995 ▶). For isotypic compounds, see: Tsvyashchenko (1986 ▶); Romaka et al. (2011 ▶); Buschow & van der Goot (1969 ▶); Givord & Lemaire (1971 ▶). For structure refinements of other compounds in the Dy–Ni system, see: Levytskyy et al. (2012a ▶,b ▶).

Experimental  

Crystal data  

• Dy₃Ni

• M _r = 546.21

• Orthorhombic,

• a = 6.863 (3) Å

• b = 9.553 (3) Å

• c = 6.302 (2) Å

• V = 413.2 (3) ų

• Z = 4

• Mo Kα radiation

• μ = 57.86 mm⁻¹

• T = 293 K

• 0.14 × 0.11 × 0.10 mm

Data collection  

• Stoe IPDS II diffractometer

• Absorption correction: numerical (X-RED; Stoe & Cie, 2009 ▶) T _min = 0.007, T _max = 0.026

• 973 measured reflections

• 582 independent reflections

• 447 reflections with I > 2σ(I)

• R _int = 0.042

Refinement  

• R[F ² > 2σ(F ²)] = 0.042

• wR(F ²) = 0.052

• S = 1.12

• 582 reflections

• 23 parameters

• Δρ_max = 2.82 e Å⁻³

• Δρ_min = −2.65 e Å⁻³

Data collection: X-AREA (Stoe & Cie, 2009 ▶); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SIR2011 (Burla et al., 2012 ▶); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008 ▶) and WinGX (Farrugia, 2012 ▶); molecular graphics: DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

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

supplementary crystallographic information

1. Comment

Lattice parameters for RE₃Ni compounds with RE = Y, La, Pr, Nd, Sm, Gd–Tm, have been determined and their crystal structures reported to be isotypic with the Fe₃C (or Al₃Ni) type structure which includes also Dy₃Ni (Lemaire & Paccard, 1967). According to the phase diagram of the Dy–Ni system (Zheng & Wang, 1982), Dy₃Ni is stable below 1035 K and is formed by the peritectic reaction: Dy + L→ Dy₃Ni.

Similar isotypic RE₃Co compounds were also reported (Buschow & van der Goot, 1969) for RE = Y, La, Pr, Nd, Sm, Gd–Er. Lu₃Co has been prepared by Givord & Lemaire (1971), Lu₃Ni by Romaka et al. (2011). Tsvyashchenko (1986) synthesized Yb₃Co and Yb₃Ni at high pressure. According to Tsvyashchenko (1986), Yb₃Co adopts the Fe₃C type structure and Yb₃Ni the Al₃Ni structure type. On the other hand, Lemaire & Paccard (1967) claimed the RE₃Ni compounds to have the same structure as the RE₃Co compounds. To clarify the confusion with the assigned structure types, we have studied literature data for the Fe₃C (Hendricks, 1930) and the Al₃Ni (Bradley & Taylor, 1937) prototype structures, concluding that Al₃Ni and Fe₃C are isotypic. In accordance with the majority in literature, we will use the Fe₃C structure type for classification as it has been reported earlier.

Recently, two binary compounds of the Dy–Ni system have been redetermined using single-crystal X-ray data (Levytskyy et al., 2012a,b). Here we present the results of the single-crystal X-ray analysis of Dy₃Ni. Details of the crystal structure have not been investigated before, and only isotypism with the Fe₃C was reported together with lattice parameters (Lemaire & Paccard, 1967).

The structure of Dy₃Ni is characterized by formation of trigonal prisms of Dy atoms with Ni atom enclosed in the centre. A view of the crystal structure of Dy₃Ni is shown in Fig. 1. The value of the displacement parameter U₂₂ for the Ni atom displays a high anisotropy in the b direction which may have an influence on some physical properties of the compound. Magnetic properties of Dy₃Ni were reported by Talik et al. (1996) and generally confirm this assumption which is also valid for the isotypic Dy₃Co (Baranov et al., 1995).

In Fig. 2 the ac projection of the unit cell and the coordination polyhedra for all atom types in Dy₃Ni are shown. The coordination number for Dy1 (site symmetry .m., Wyckoff site 4 c) is 15 with bonding to 12 Dy and 3 Ni atoms. The coordination number for Dy2 (site symmetry 1, Wyckoff site 8 d) is 14, resulting in a distorted Frank–Kasper polyhedron defined by 11 Dy and 3 Ni atoms. The coordination number for Ni (site symmetry .m., Wyckoff site 4 c) is 9, resulting in a slightly distorted tricapped trigonal prism made up of 9 Dy atoms.

The analysis of interatomic distances shows a slight decrease of some Dy–Ni distances. This feature is in good agreement with the observed Ho–Co distances for previously reported Ho₃Co (Buschow & van der Goot, 1969). The explanation of this fact may be deduced from an electronic band structure calculation.

2. Experimental

The sample was prepared from powdered commercially available pure elements: sublimed bulk pieces of dysprosium metal with a claimed purity of 99.99 at.% (Alfa Aesar, Johnson Matthey) and electrolytic nickel (99.99% pure) pieces (Aldrich). A mixture of the powders was compacted into a pellet. It was arc-melted under an argon atmosphere on a water-cooled copper hearth. The alloy button (~1 g) was turned over and remelted three times to improve homogeneity. Subsequently, the sample was annealed in an evacuated silica tube under an argon atmosphere for four weeks at 870 K. Shiny metallic gray plate-like crystals were isolated mechanically with a help of microscope by crushing the sample.

3. Refinement

The atomic positions found from the direct methods structure solution were in good agreement with those from the Fe₃C structure type (Hendricks, 1930) and were used as starting point for the structure refinement. The highest Fourier difference peak of 2.82 e Å^-3 is at (0.0340 0.75 0.1598) and 1.36 Å away from the Dy2 atom. The deepest hole of -2.65 e Å^-3 is at (0.0358 0.25 0.0220) and 1.01 Å away from the Ni atom.

Figures

Fig. 1.

Perspective view of the crystal structure of Dy3Ni. The unit cell and coordination trigonal prisms for Ni atoms are emphasized. The stacking edge of these prisms is marked by red colour. Atoms are represented by their anisotropic displacement ellipsoids at the 99.9% probability level.

Fig. 2.

The ac projection of the unit cell and coordination polyhedra for all types of atoms in the Dy3Ni structure.

Crystal data

Dy3Ni	Dx = 8.781 Mg m−3
Mr = 546.21	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pnma	Cell parameters from 2575 reflections
a = 6.863 (3) Å	θ = 3.7–29.5°
b = 9.553 (3) Å	µ = 57.86 mm−1
c = 6.302 (2) Å	T = 293 K
V = 413.2 (3) Å3	Block, metallic gray
Z = 4	0.14 × 0.11 × 0.10 mm
F(000) = 904

Data collection

Stoe IPDS II diffractometer	447 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.042
ω scans	θmax = 29.6°, θmin = 3.9°
Absorption correction: numerical (X-RED; Stoe & Cie, 2009)	h = 0→9
Tmin = 0.007, Tmax = 0.026	k = 0→12
973 measured reflections	l = −8→8
582 independent reflections

Refinement

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)] = 0.042	w = 1/[σ2(Fo2) + (0.0141P)2] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.052	(Δ/σ)max < 0.001
S = 1.12	Δρmax = 2.82 e Å−3
582 reflections	Δρmin = −2.65 e Å−3
23 parameters	Extinction correction: SHELXL2013 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraints	Extinction coefficient: 0.00030 (10)

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.

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

	x	y	z	Uiso*/Ueq
Dy1	0.17975 (10)	0.06439 (6)	0.17745 (9)	0.01479 (17)
Dy2	0.03218 (14)	0.2500	0.63694 (13)	0.0147 (2)
Ni	0.3917 (4)	0.2500	0.4477 (4)	0.0197 (5)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Dy1	0.0150 (3)	0.0151 (3)	0.0143 (2)	0.0001 (3)	0.0003 (3)	−0.0004 (2)
Dy2	0.0158 (5)	0.0144 (4)	0.0138 (4)	0.000	0.0014 (3)	0.000
Ni	0.0131 (12)	0.0268 (14)	0.0192 (11)	0.000	0.0003 (10)	0.000

Geometric parameters (Å, º)

Dy1—Nii	2.770 (2)	Dy2—Dy1xii	3.5361 (12)
Dy1—Ni	2.856 (2)	Dy2—Dy1vi	3.5433 (12)
Dy1—Niii	3.3700 (15)	Dy2—Dy1viii	3.5944 (14)
Dy1—Dy1iii	3.5174 (11)	Dy2—Dy1i	3.5944 (14)
Dy1—Dy1iv	3.5174 (11)	Dy2—Dy1xiii	3.6047 (12)
Dy1—Dy2v	3.5361 (12)	Dy2—Dy1iii	3.6047 (12)
Dy1—Dy2	3.5433 (12)	Dy2—Dy2xiv	3.7156 (15)
Dy1—Dy1vi	3.5462 (16)	Dy2—Dy2xi	3.7156 (15)
Dy1—Dy1vii	3.5502 (15)	Ni—Dy1x	2.770 (2)
Dy1—Dy1viii	3.5512 (15)	Ni—Dy1ix	2.770 (2)
Dy1—Dy1ix	3.5512 (15)	Ni—Dy2xiv	2.790 (3)
Dy1—Dy2x	3.5944 (14)	Ni—Dy1vi	2.856 (2)
Dy2—Ni	2.740 (3)	Ni—Dy1xiii	3.3700 (15)
Dy2—Nixi	2.790 (3)	Ni—Dy1iii	3.3700 (15)
Dy2—Dy1v	3.5361 (12)
Nii—Dy1—Ni	97.80 (5)	Dy1—Dy2—Dy1vi	60.06 (3)
Nii—Dy1—Niii	110.14 (3)	Ni—Dy2—Dy1viii	111.46 (6)
Ni—Dy1—Niii	152.06 (4)	Nixi—Dy2—Dy1viii	106.54 (6)
Nii—Dy1—Dy1iii	132.42 (6)	Dy1v—Dy2—Dy1viii	59.11 (2)
Ni—Dy1—Dy1iii	62.83 (4)	Dy1xii—Dy2—Dy1viii	108.94 (3)
Niii—Dy1—Dy1iii	96.49 (5)	Dy1—Dy2—Dy1viii	59.67 (3)
Nii—Dy1—Dy1iv	99.46 (5)	Dy1vi—Dy2—Dy1viii	89.35 (3)
Ni—Dy1—Dy1iv	127.71 (7)	Ni—Dy2—Dy1i	111.46 (6)
Niii—Dy1—Dy1iv	48.95 (4)	Nixi—Dy2—Dy1i	106.54 (6)
Dy1iii—Dy1—Dy1iv	127.23 (4)	Dy1v—Dy2—Dy1i	108.94 (3)
Nii—Dy1—Dy2v	110.13 (6)	Dy1xii—Dy2—Dy1i	59.11 (2)
Ni—Dy1—Dy2v	122.64 (5)	Dy1—Dy2—Dy1i	89.35 (3)
Niii—Dy1—Dy2v	47.57 (5)	Dy1vi—Dy2—Dy1i	59.67 (3)
Dy1iii—Dy1—Dy2v	61.27 (3)	Dy1viii—Dy2—Dy1i	59.12 (3)
Dy1iv—Dy1—Dy2v	96.43 (3)	Ni—Dy2—Dy1xiii	62.42 (3)
Nii—Dy1—Dy2	73.05 (5)	Nixi—Dy2—Dy1xiii	97.07 (4)
Ni—Dy1—Dy2	49.28 (6)	Dy1v—Dy2—Dy1xiii	155.48 (3)
Niii—Dy1—Dy2	139.07 (5)	Dy1xii—Dy2—Dy1xiii	59.64 (3)
Dy1iii—Dy1—Dy2	61.40 (2)	Dy1—Dy2—Dy1xiii	108.55 (3)
Dy1iv—Dy1—Dy2	170.23 (3)	Dy1vi—Dy2—Dy1xiii	58.947 (18)
Dy2v—Dy1—Dy2	92.13 (2)	Dy1viii—Dy2—Dy1xiii	144.99 (2)
Nii—Dy1—Dy1vi	50.21 (4)	Dy1i—Dy2—Dy1xiii	89.83 (3)
Ni—Dy1—Dy1vi	51.63 (4)	Ni—Dy2—Dy1iii	62.42 (3)
Niii—Dy1—Dy1vi	153.03 (4)	Nixi—Dy2—Dy1iii	97.07 (4)
Dy1iii—Dy1—Dy1vi	110.47 (2)	Dy1v—Dy2—Dy1iii	59.64 (3)
Dy1iv—Dy1—Dy1vi	110.47 (2)	Dy1xii—Dy2—Dy1iii	155.48 (3)
Dy2v—Dy1—Dy1vi	148.141 (19)	Dy1—Dy2—Dy1iii	58.947 (18)
Dy2—Dy1—Dy1vi	59.972 (15)	Dy1vi—Dy2—Dy1iii	108.55 (3)
Nii—Dy1—Dy1vii	63.03 (5)	Dy1viii—Dy2—Dy1iii	89.83 (3)
Ni—Dy1—Dy1vii	160.83 (5)	Dy1i—Dy2—Dy1iii	144.99 (2)
Niii—Dy1—Dy1vii	47.11 (5)	Dy1xiii—Dy2—Dy1iii	112.85 (4)
Dy1iii—Dy1—Dy1vii	129.32 (4)	Ni—Dy2—Dy2xiv	48.35 (6)
Dy1iv—Dy1—Dy1vii	60.32 (3)	Nixi—Dy2—Dy2xiv	87.67 (7)
Dy2v—Dy1—Dy1vii	68.17 (3)	Dy1v—Dy2—Dy2xiv	104.66 (3)
Dy2—Dy1—Dy1vii	119.32 (4)	Dy1xii—Dy2—Dy2xiv	104.66 (3)
Dy1vi—Dy1—Dy1vii	110.28 (2)	Dy1—Dy2—Dy2xiv	92.83 (3)
Nii—Dy1—Dy1viii	51.95 (5)	Dy1vi—Dy2—Dy2xiv	92.83 (3)
Ni—Dy1—Dy1viii	109.78 (6)	Dy1viii—Dy2—Dy2xiv	146.39 (2)
Niii—Dy1—Dy1viii	88.29 (5)	Dy1i—Dy2—Dy2xiv	146.39 (2)
Dy1iii—Dy1—Dy1viii	91.96 (3)	Dy1xiii—Dy2—Dy2xiv	57.75 (2)
Dy1iv—Dy1—Dy1viii	119.71 (3)	Dy1iii—Dy2—Dy2xiv	57.75 (2)
Dy2v—Dy1—Dy1viii	61.14 (2)	Ni—Dy2—Dy2xi	176.75 (7)
Dy2—Dy1—Dy1viii	60.88 (2)	Nixi—Dy2—Dy2xi	47.22 (6)
Dy1vi—Dy1—Dy1viii	90.0	Dy1v—Dy2—Dy2xi	59.55 (2)
Dy1vii—Dy1—Dy1viii	59.38 (3)	Dy1xii—Dy2—Dy2xi	59.55 (2)
Nii—Dy1—Dy1ix	139.72 (4)	Dy1—Dy2—Dy2xi	125.27 (3)
Ni—Dy1—Dy1ix	49.80 (5)	Dy1vi—Dy2—Dy2xi	125.27 (3)
Niii—Dy1—Dy1ix	104.55 (5)	Dy1viii—Dy2—Dy2xi	65.79 (3)
Dy1iii—Dy1—Dy1ix	60.29 (3)	Dy1i—Dy2—Dy2xi	65.79 (3)
Dy1iv—Dy1—Dy1ix	88.04 (3)	Dy1xiii—Dy2—Dy2xi	118.64 (2)
Dy2v—Dy1—Dy1ix	108.20 (2)	Dy1iii—Dy2—Dy2xi	118.64 (2)
Dy2—Dy1—Dy1ix	93.77 (3)	Dy2xiv—Dy2—Dy2xi	134.90 (5)
Dy1vi—Dy1—Dy1ix	90.0	Dy2—Ni—Dy1x	140.04 (4)
Dy1vii—Dy1—Dy1ix	146.49 (3)	Dy2—Ni—Dy1ix	140.04 (4)
Dy1viii—Dy1—Dy1ix	150.16 (4)	Dy1x—Ni—Dy1ix	79.59 (8)
Nii—Dy1—Dy2x	90.43 (6)	Dy2—Ni—Dy2xiv	84.43 (7)
Ni—Dy1—Dy2x	71.33 (6)	Dy1x—Ni—Dy2xiv	91.17 (8)
Niii—Dy1—Dy2x	107.50 (5)	Dy1ix—Ni—Dy2xiv	91.17 (8)
Dy1iii—Dy1—Dy2x	118.81 (4)	Dy2—Ni—Dy1	78.53 (7)
Dy1iv—Dy1—Dy2x	59.62 (2)	Dy1x—Ni—Dy1	126.22 (9)
Dy2v—Dy1—Dy2x	151.42 (2)	Dy1ix—Ni—Dy1	78.25 (5)
Dy2—Dy1—Dy2x	113.33 (3)	Dy2xiv—Ni—Dy1	137.35 (5)
Dy1vi—Dy1—Dy2x	60.442 (16)	Dy2—Ni—Dy1vi	78.53 (7)
Dy1vii—Dy1—Dy2x	106.94 (4)	Dy1x—Ni—Dy1vi	78.25 (5)
Dy1viii—Dy1—Dy2x	142.39 (2)	Dy1ix—Ni—Dy1vi	126.22 (9)
Dy1ix—Dy1—Dy2x	59.45 (3)	Dy2xiv—Ni—Dy1vi	137.35 (5)
Ni—Dy2—Ni3xi	136.02 (9)	Dy1—Ni—Dy1vi	76.74 (7)
Ni—Dy2—Dy1v	120.95 (2)	Dy2—Ni—Dy1xiii	71.46 (5)
Nixi—Dy2—Dy1v	63.09 (3)	Dy1x—Ni—Dy1xiii	69.86 (3)
Ni—Dy2—Dy1xii	120.95 (2)	Dy1ix—Ni—Dy1xiii	142.80 (9)
Nixi—Dy2—Dy1xii	63.09 (3)	Dy2xiv—Ni—Dy1xiii	69.34 (4)
Dy1v—Dy2—Dy1xii	116.28 (4)	Dy1—Ni—Dy1xiii	137.33 (9)
Ni—Dy2—Dy1	52.19 (4)	Dy1vi—Ni—Dy1xiii	68.22 (3)
Nixi—Dy2—Dy1	149.959 (16)	Dy2—Ni—Dy1iii	71.46 (5)
Dy1v—Dy2—Dy1	87.87 (3)	Dy1x—Ni—Dy1iii	142.80 (9)
Dy1xii—Dy2—Dy1	144.38 (2)	Dy1ix—Ni—Dy1iii	69.86 (3)
Ni—Dy2—Dy1vi	52.19 (4)	Dy2xiv—Ni—Dy1iii	69.34 (4)
Nixi—Dy2—Dy1vi	149.959 (16)	Dy1—Ni—Dy1iii	68.22 (3)
Dy1v—Dy2—Dy1vi	144.38 (2)	Dy1vi—Ni—Dy1iii	137.33 (9)
Dy1xii—Dy2—Dy1vi	87.87 (2)	Dy1xiii—Ni—Dy1iii	126.05 (8)

Symmetry codes: (i) x−1/2, −y+1/2, −z+1/2; (ii) −x+1/2, y−1/2, z−1/2; (iii) −x+1/2, −y, z+1/2; (iv) −x+1/2, −y, z−1/2; (v) −x, −y, −z+1; (vi) x, −y+1/2, z; (vii) −x, −y, −z; (viii) x−1/2, y, −z+1/2; (ix) x+1/2, y, −z+1/2; (x) x+1/2, −y+1/2, −z+1/2; (xi) x−1/2, −y+1/2, −z+3/2; (xii) −x, y+1/2, −z+1; (xiii) −x+1/2, y+1/2, z+1/2; (xiv) x+1/2, −y+1/2, −z+3/2.