supplementary materials


Acta Cryst. (2013). E69, i80    [ doi:10.1107/S1600536813028717 ]

Redetermination of Dy3Ni from single-crystal X-ray data

V. Levytskyy, V. Babizhetskyy, B. Kotur and V. Smetana

Abstract top

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.

Comment top

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.

Related literature top

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 top

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.

Refinement top

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.

Computing details top

Data collection: X-AREA (Stoe & Cie, 2009); cell refinement: X-AREA (Stoe & Cie, 2009); data reduction: X-AREA (Stoe & Cie, 2009); 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).

Figures top
[Figure 1] 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.
[Figure 2] Fig. 2. The ac projection of the unit cell and coordination polyhedra for all types of atoms in the Dy3Ni structure.
Tridysprosium nickel top
Crystal data top
Dy3NiDx = 8.781 Mg m3
Mr = 546.21Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, PnmaCell parameters from 2575 reflections
a = 6.863 (3) Åθ = 3.7–29.5°
b = 9.553 (3) ŵ = 57.86 mm1
c = 6.302 (2) ÅT = 293 K
V = 413.2 (3) Å3Block, metallic gray
Z = 40.14 × 0.11 × 0.10 mm
F(000) = 904
Data collection top
Stoe IPDS II
diffractometer
447 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.042
ω scansθmax = 29.6°, θmin = 3.9°
Absorption correction: numerical
(X-RED; Stoe & Cie, 2009)
h = 09
Tmin = 0.007, Tmax = 0.026k = 012
973 measured reflectionsl = 88
582 independent reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary 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 = 1.12Δρmax = 2.82 e Å3
582 reflectionsΔρmin = 2.65 e Å3
23 parametersExtinction correction: SHELXL2013 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.00030 (10)
Crystal data top
Dy3NiV = 413.2 (3) Å3
Mr = 546.21Z = 4
Orthorhombic, PnmaMo Kα radiation
a = 6.863 (3) ŵ = 57.86 mm1
b = 9.553 (3) ÅT = 293 K
c = 6.302 (2) Å0.14 × 0.11 × 0.10 mm
Data collection top
Stoe IPDS II
diffractometer
582 independent reflections
Absorption correction: numerical
(X-RED; Stoe & Cie, 2009)
447 reflections with I > 2σ(I)
Tmin = 0.007, Tmax = 0.026Rint = 0.042
973 measured reflectionsθmax = 29.6°
Refinement top
R[F2 > 2σ(F2)] = 0.042Δρmax = 2.82 e Å3
wR(F2) = 0.052Δρmin = 2.65 e Å3
S = 1.12Absolute structure: ?
582 reflectionsAbsolute structure parameter: ?
23 parametersRogers parameter: ?
0 restraints
Special details top

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 (Å2) top
xyzUiso*/Ueq
Dy10.17975 (10)0.06439 (6)0.17745 (9)0.01479 (17)
Dy20.03218 (14)0.25000.63694 (13)0.0147 (2)
Ni0.3917 (4)0.25000.4477 (4)0.0197 (5)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Dy10.0150 (3)0.0151 (3)0.0143 (2)0.0001 (3)0.0003 (3)0.0004 (2)
Dy20.0158 (5)0.0144 (4)0.0138 (4)0.0000.0014 (3)0.000
Ni0.0131 (12)0.0268 (14)0.0192 (11)0.0000.0003 (10)0.000
Geometric parameters (Å, º) top
Dy1—Nii2.770 (2)Dy2—Dy1xii3.5361 (12)
Dy1—Ni2.856 (2)Dy2—Dy1vi3.5433 (12)
Dy1—Niii3.3700 (15)Dy2—Dy1viii3.5944 (14)
Dy1—Dy1iii3.5174 (11)Dy2—Dy1i3.5944 (14)
Dy1—Dy1iv3.5174 (11)Dy2—Dy1xiii3.6047 (12)
Dy1—Dy2v3.5361 (12)Dy2—Dy1iii3.6047 (12)
Dy1—Dy23.5433 (12)Dy2—Dy2xiv3.7156 (15)
Dy1—Dy1vi3.5462 (16)Dy2—Dy2xi3.7156 (15)
Dy1—Dy1vii3.5502 (15)Ni—Dy1x2.770 (2)
Dy1—Dy1viii3.5512 (15)Ni—Dy1ix2.770 (2)
Dy1—Dy1ix3.5512 (15)Ni—Dy2xiv2.790 (3)
Dy1—Dy2x3.5944 (14)Ni—Dy1vi2.856 (2)
Dy2—Ni2.740 (3)Ni—Dy1xiii3.3700 (15)
Dy2—Nixi2.790 (3)Ni—Dy1iii3.3700 (15)
Dy2—Dy1v3.5361 (12)
Nii—Dy1—Ni97.80 (5)Dy1—Dy2—Dy1vi60.06 (3)
Nii—Dy1—Niii110.14 (3)Ni—Dy2—Dy1viii111.46 (6)
Ni—Dy1—Niii152.06 (4)Nixi—Dy2—Dy1viii106.54 (6)
Nii—Dy1—Dy1iii132.42 (6)Dy1v—Dy2—Dy1viii59.11 (2)
Ni—Dy1—Dy1iii62.83 (4)Dy1xii—Dy2—Dy1viii108.94 (3)
Niii—Dy1—Dy1iii96.49 (5)Dy1—Dy2—Dy1viii59.67 (3)
Nii—Dy1—Dy1iv99.46 (5)Dy1vi—Dy2—Dy1viii89.35 (3)
Ni—Dy1—Dy1iv127.71 (7)Ni—Dy2—Dy1i111.46 (6)
Niii—Dy1—Dy1iv48.95 (4)Nixi—Dy2—Dy1i106.54 (6)
Dy1iii—Dy1—Dy1iv127.23 (4)Dy1v—Dy2—Dy1i108.94 (3)
Nii—Dy1—Dy2v110.13 (6)Dy1xii—Dy2—Dy1i59.11 (2)
Ni—Dy1—Dy2v122.64 (5)Dy1—Dy2—Dy1i89.35 (3)
Niii—Dy1—Dy2v47.57 (5)Dy1vi—Dy2—Dy1i59.67 (3)
Dy1iii—Dy1—Dy2v61.27 (3)Dy1viii—Dy2—Dy1i59.12 (3)
Dy1iv—Dy1—Dy2v96.43 (3)Ni—Dy2—Dy1xiii62.42 (3)
Nii—Dy1—Dy273.05 (5)Nixi—Dy2—Dy1xiii97.07 (4)
Ni—Dy1—Dy249.28 (6)Dy1v—Dy2—Dy1xiii155.48 (3)
Niii—Dy1—Dy2139.07 (5)Dy1xii—Dy2—Dy1xiii59.64 (3)
Dy1iii—Dy1—Dy261.40 (2)Dy1—Dy2—Dy1xiii108.55 (3)
Dy1iv—Dy1—Dy2170.23 (3)Dy1vi—Dy2—Dy1xiii58.947 (18)
Dy2v—Dy1—Dy292.13 (2)Dy1viii—Dy2—Dy1xiii144.99 (2)
Nii—Dy1—Dy1vi50.21 (4)Dy1i—Dy2—Dy1xiii89.83 (3)
Ni—Dy1—Dy1vi51.63 (4)Ni—Dy2—Dy1iii62.42 (3)
Niii—Dy1—Dy1vi153.03 (4)Nixi—Dy2—Dy1iii97.07 (4)
Dy1iii—Dy1—Dy1vi110.47 (2)Dy1v—Dy2—Dy1iii59.64 (3)
Dy1iv—Dy1—Dy1vi110.47 (2)Dy1xii—Dy2—Dy1iii155.48 (3)
Dy2v—Dy1—Dy1vi148.141 (19)Dy1—Dy2—Dy1iii58.947 (18)
Dy2—Dy1—Dy1vi59.972 (15)Dy1vi—Dy2—Dy1iii108.55 (3)
Nii—Dy1—Dy1vii63.03 (5)Dy1viii—Dy2—Dy1iii89.83 (3)
Ni—Dy1—Dy1vii160.83 (5)Dy1i—Dy2—Dy1iii144.99 (2)
Niii—Dy1—Dy1vii47.11 (5)Dy1xiii—Dy2—Dy1iii112.85 (4)
Dy1iii—Dy1—Dy1vii129.32 (4)Ni—Dy2—Dy2xiv48.35 (6)
Dy1iv—Dy1—Dy1vii60.32 (3)Nixi—Dy2—Dy2xiv87.67 (7)
Dy2v—Dy1—Dy1vii68.17 (3)Dy1v—Dy2—Dy2xiv104.66 (3)
Dy2—Dy1—Dy1vii119.32 (4)Dy1xii—Dy2—Dy2xiv104.66 (3)
Dy1vi—Dy1—Dy1vii110.28 (2)Dy1—Dy2—Dy2xiv92.83 (3)
Nii—Dy1—Dy1viii51.95 (5)Dy1vi—Dy2—Dy2xiv92.83 (3)
Ni—Dy1—Dy1viii109.78 (6)Dy1viii—Dy2—Dy2xiv146.39 (2)
Niii—Dy1—Dy1viii88.29 (5)Dy1i—Dy2—Dy2xiv146.39 (2)
Dy1iii—Dy1—Dy1viii91.96 (3)Dy1xiii—Dy2—Dy2xiv57.75 (2)
Dy1iv—Dy1—Dy1viii119.71 (3)Dy1iii—Dy2—Dy2xiv57.75 (2)
Dy2v—Dy1—Dy1viii61.14 (2)Ni—Dy2—Dy2xi176.75 (7)
Dy2—Dy1—Dy1viii60.88 (2)Nixi—Dy2—Dy2xi47.22 (6)
Dy1vi—Dy1—Dy1viii90.0Dy1v—Dy2—Dy2xi59.55 (2)
Dy1vii—Dy1—Dy1viii59.38 (3)Dy1xii—Dy2—Dy2xi59.55 (2)
Nii—Dy1—Dy1ix139.72 (4)Dy1—Dy2—Dy2xi125.27 (3)
Ni—Dy1—Dy1ix49.80 (5)Dy1vi—Dy2—Dy2xi125.27 (3)
Niii—Dy1—Dy1ix104.55 (5)Dy1viii—Dy2—Dy2xi65.79 (3)
Dy1iii—Dy1—Dy1ix60.29 (3)Dy1i—Dy2—Dy2xi65.79 (3)
Dy1iv—Dy1—Dy1ix88.04 (3)Dy1xiii—Dy2—Dy2xi118.64 (2)
Dy2v—Dy1—Dy1ix108.20 (2)Dy1iii—Dy2—Dy2xi118.64 (2)
Dy2—Dy1—Dy1ix93.77 (3)Dy2xiv—Dy2—Dy2xi134.90 (5)
Dy1vi—Dy1—Dy1ix90.0Dy2—Ni—Dy1x140.04 (4)
Dy1vii—Dy1—Dy1ix146.49 (3)Dy2—Ni—Dy1ix140.04 (4)
Dy1viii—Dy1—Dy1ix150.16 (4)Dy1x—Ni—Dy1ix79.59 (8)
Nii—Dy1—Dy2x90.43 (6)Dy2—Ni—Dy2xiv84.43 (7)
Ni—Dy1—Dy2x71.33 (6)Dy1x—Ni—Dy2xiv91.17 (8)
Niii—Dy1—Dy2x107.50 (5)Dy1ix—Ni—Dy2xiv91.17 (8)
Dy1iii—Dy1—Dy2x118.81 (4)Dy2—Ni—Dy178.53 (7)
Dy1iv—Dy1—Dy2x59.62 (2)Dy1x—Ni—Dy1126.22 (9)
Dy2v—Dy1—Dy2x151.42 (2)Dy1ix—Ni—Dy178.25 (5)
Dy2—Dy1—Dy2x113.33 (3)Dy2xiv—Ni—Dy1137.35 (5)
Dy1vi—Dy1—Dy2x60.442 (16)Dy2—Ni—Dy1vi78.53 (7)
Dy1vii—Dy1—Dy2x106.94 (4)Dy1x—Ni—Dy1vi78.25 (5)
Dy1viii—Dy1—Dy2x142.39 (2)Dy1ix—Ni—Dy1vi126.22 (9)
Dy1ix—Dy1—Dy2x59.45 (3)Dy2xiv—Ni—Dy1vi137.35 (5)
Ni—Dy2—Ni3xi136.02 (9)Dy1—Ni—Dy1vi76.74 (7)
Ni—Dy2—Dy1v120.95 (2)Dy2—Ni—Dy1xiii71.46 (5)
Nixi—Dy2—Dy1v63.09 (3)Dy1x—Ni—Dy1xiii69.86 (3)
Ni—Dy2—Dy1xii120.95 (2)Dy1ix—Ni—Dy1xiii142.80 (9)
Nixi—Dy2—Dy1xii63.09 (3)Dy2xiv—Ni—Dy1xiii69.34 (4)
Dy1v—Dy2—Dy1xii116.28 (4)Dy1—Ni—Dy1xiii137.33 (9)
Ni—Dy2—Dy152.19 (4)Dy1vi—Ni—Dy1xiii68.22 (3)
Nixi—Dy2—Dy1149.959 (16)Dy2—Ni—Dy1iii71.46 (5)
Dy1v—Dy2—Dy187.87 (3)Dy1x—Ni—Dy1iii142.80 (9)
Dy1xii—Dy2—Dy1144.38 (2)Dy1ix—Ni—Dy1iii69.86 (3)
Ni—Dy2—Dy1vi52.19 (4)Dy2xiv—Ni—Dy1iii69.34 (4)
Nixi—Dy2—Dy1vi149.959 (16)Dy1—Ni—Dy1iii68.22 (3)
Dy1v—Dy2—Dy1vi144.38 (2)Dy1vi—Ni—Dy1iii137.33 (9)
Dy1xii—Dy2—Dy1vi87.87 (2)Dy1xiii—Ni—Dy1iii126.05 (8)
Symmetry codes: (i) x1/2, y+1/2, z+1/2; (ii) x+1/2, y1/2, z1/2; (iii) x+1/2, y, z+1/2; (iv) x+1/2, y, z1/2; (v) x, y, z+1; (vi) x, y+1/2, z; (vii) x, y, z; (viii) x1/2, y, z+1/2; (ix) x+1/2, y, z+1/2; (x) x+1/2, y+1/2, z+1/2; (xi) x1/2, 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.

Experimental details

Crystal data
Chemical formulaDy3Ni
Mr546.21
Crystal system, space groupOrthorhombic, Pnma
Temperature (K)293
a, b, c (Å)6.863 (3), 9.553 (3), 6.302 (2)
V3)413.2 (3)
Z4
Radiation typeMo Kα
µ (mm1)57.86
Crystal size (mm)0.14 × 0.11 × 0.10
Data collection
DiffractometerStoe IPDS II
diffractometer
Absorption correctionNumerical
(X-RED; Stoe & Cie, 2009)
Tmin, Tmax0.007, 0.026
No. of measured, independent and
observed [I > 2σ(I)] reflections
973, 582, 447
Rint0.042
(sin θ/λ)max1)0.696
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.042, 0.052, 1.12
No. of reflections582
No. of parameters23
No. of restraints0
Δρmax, Δρmin (e Å3)2.82, 2.65

Computer programs: X-AREA (Stoe & Cie, 2009), SIR2011 (Burla et al., 2012), SHELXL2013 (Sheldrick, 2008) and WinGX (Farrugia, 2012), DIAMOND (Brandenburg, 2006), publCIF (Westrip, 2010).

references
References top

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