inorganic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

LiDy(PO3)4

aLaboratoire d'Application de la Chimie aux Ressources et Substances Naturelles et à l'Environnement, Faculté des Sciences de Bizerte, 7021 Zarzouna, Tunisia, and bUnité des Matériaux de Terres Rares, Centre National de Recherches en Sciences des Matériaux, BP 95, 2050 Hammam-Lif, Tunisia
*Correspondence e-mail: mokhtar.ferid@inrst.rnrt.tn

(Received 30 May 2008; accepted 3 June 2008; online 13 June 2008)

Single crystals of lithium dysprosium polyphosphate, LiDy(PO3)4, were prepared by the flux method. The atomic arrangement is built up by infinite (PO3)n chains extending along the b axis. Dy3+ and Li+ cations alternate in the middle of four such chains, with Dy⋯Li distances of 3.54 (1) and 3.48 (1) Å. The DyO8 dodeca­hedra and LiO4 tetra­hedra deviate significantly from the ideal geometry. Both Dy and Li occupy special positions (Wyckoff position 4e, site symmetry 2).

Related literature

For related literature, see: Averbuch-Pouchot & Bagieu Beucher (1987[Averbuch-Pouchot, M. T. & Bagieu Beucher, M. (1987). Z. Anorg. Allg. Chem. 552, 171-180.]); Ben Zarkouna et al. (2005[Ben Zarkouna, E., Férid, M. & Driss, A. (2005). Mater. Res. Bull. 40, 198-1992.]; 2007[Ben Zarkouna, E., Horchani-Naifer, K., Férid, M. & Driss, A. (2007). Acta Cryst. E63, i1-i2.]); Ben Zarkouna & Driss (2004[Ben Zarkouna, E. & Driss, A. (2004). Acta Cryst. E60, i102-i104.]); Durif (1995[Durif, A. (1995). Crystal Chemistry of Condensed Phosphates. New York: Plenum Press.]); Ettis et al. (2006[Ettis, H., Naili, H. & Mhiri, T. (2006). J. Solid State Chem. 179, 3107-3113.]); Férid (2006[Férid, M. (2006). Etude des propriétés cristallochimiques et physiques de phosphates condensés de terres rares. Paris: Publibook.]); Hashimoto et al. (1991[Hashimoto, N., Takada, Y., Sato, K. & Ibuki, S. (1991). J. Lumin. 48-49, 893-897.]); Hong (1975[Hong, H. Y. P. (1975). Mater. Res. Bull. 10, 635-640.]); Horchani et al. (2003[Horchani, K., Gâcon, J. C., Férid, M., Trabelsi-Ayadi, M., Krachni, G. K. & Liu, G. K. (2003). Opt. Mater. 24, 169-174.]); Liu & Li (1983[Liu, J.-C. & Li, D.-Y. (1983). Acta Phys. Sinica, 32, 786-790.]); Chehimi-Moumen & Férid (2007[Chehimi-Moumen, F. & Férid, M. (2007). Acta Cryst. E63, i129-i130.]); Koizumi (1976[Koizumi, H. (1976). Acta Cryst. B32, 266-268.]); Yamada et al. (1974[Yamada, T., Otsuka, K. & Nakano, J. (1974). J. Appl. Phys. 45, 5096-5097.]).

Experimental

Crystal data
  • LiDy(PO3)4

  • Mr = 485.32

  • Monoclinic, C 2/c

  • a = 16.269 (1) Å

  • b = 7.0236 (3) Å

  • c = 9.5781 (8) Å

  • β = 126.106 (3)°

  • V = 884.24 (10) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 9.24 mm−1

  • T = 295 (2) K

  • 0.10 × 0.09 × 0.08 mm

Data collection
  • Nonius KappaCCD diffractometer

  • Absorption correction: analytical (de Meulenaer & Tompa, 1965[Meulenaer, J. de & Tompa, H. (1965). Acta Cryst. 19, 1014-1018.]) Tmin = 0.42, Tmax = 0.45

  • 3313 measured reflections

  • 1021 independent reflections

  • 858 reflections with I > 2σ(I)

  • Rint = 0.080

Refinement
  • R[F2 > 2σ(F2)] = 0.038

  • wR(F2) = 0.087

  • S = 0.95

  • 1021 reflections

  • 83 parameters

  • Δρmax = 2.26 e Å−3

  • Δρmin = −2.13 e Å−3

Data collection: COLLECT (Nonius, 1998[Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands.]); cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]); data reduction: DENZO/SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Brandenburg, 1999[Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

Condensed phosphates of rare earth and monovalent cations of general formula MILn(PO3)4 have attracted large interest in the literature of the last three decades due to their possible application as phosphors and laser materials (Yamada et al., 1974; Hashimoto et al., 1991; Horchani et al., 2003).

In order to enrich the chemistry of this compound family, we have successfully synthesized single crystals of lithium dysprosium polyphosphate and investigated its crystal structure.

Structural studies reported for lithium lanthanide polyphosphates LiLn(PO3)4, Ln = Nd (Hong, 1975, Koizumi, 1976), Er (Liu et al., 1983, Ben Zarkouna et al., 2005),Yb (Ben Zarkouna et al., 2004), Gd (Ettis et al., 2006), Tb (Ben Zarkouna et al., 2007), showed that all these compounds crystallize in space group C2/c and have similar unit-cell parameters. However, it was reported that the lithium atom is located in the (4a) site in LiNd(PO3)4 (Hong, 1975) and LiEr(PO3)4 (Liu et al., 1983) and in the (4 e) site in the remaining structures. LiDy(PO3)4 is found to be isotypic with the latter group LiLn(PO3)4 previously reported. The corresponding asymmetric unit (Fig. 1) is formed by dysprosium and lithium atoms, both located in the (4 e) site, and two PO4 tetrahedra with all atoms in general positions.

These tetrahedra share common corners yielding infinite chains, of four tetrahedra period, extending along the 21 screw axes in the b direction. Four such chains cross the unit cell (Fig. 2).

The polyphosphate chains display two type of distances, P—O terminal ranging from 1.475 (5) to 1.500 (5)Å and P—O bridging, noticeably longer, ranging from 1.573 (5) to 1.619 (5) Å. These distances are comparable with those reported for other condensed phosphates (Durif, 1995; Averbuch-Pouchot & Bagieu Beucher, 1987; Chehimi-Moumen & Férid, 2007; Férid, 2006, Ben Zarkouna et al., 2007).

Dy3+ and Li+ cations lie alternatingly on the two-fold axis in the middle of four polyphosphate chains, with Dy—Li distances of 3.55 (1) and 3.48 (1) Å. They are coordinated by eight and four external oxygen atoms, respectively. The resulting DyO8 dodecahedra and LiO4 tetrahedra are considerably distorted (Figure 3). The Dy—O and Li—O distances range from 2.288 (5) to 2.513 (5)Å and 1.95 (1) to 1.99 (1)Å respectively. The DyO8 dodecahedra share corners and edges with neighbouring LiO4 (Fig. 3) and PO4 tetrahedra building a three dimensional network (Fig. 4). It can be noted that, in the present arrangement, the DyO8 dodecahedra are isolated from each other, the shortest Dy—Dy distance is 5.563 (5) Å.

Related literature top

For related literature, see: Averbuch-Pouchot & Bagieu Beucher (1987); Ben Zarkouna, Férid & Driss (2005); Ben Zarkouna & Driss (2004), Ben Zarkouna, Horchani-Naifer et al. (2007); Durif (1995); Ettis et al. (2006); Férid (2006); Hashimoto et al. (1991); Hong (1975); Horchani et al. (2003); Liu & Li (1983); Chehimi-Moumen & Férid (2007); Koizumi (1976); Yamada et al. (1974).

Experimental top

A mixture of Li2CO3 (2 g), Dy2O3 (0.5 g) and H3PO4 (85%, 17 ml), were mixed in a vitreous carbon crucible and preheated progressively to 473 K four 2 h. The temperature was then raised and kept at 600 K for 15 days. Colourless single crystals of LiDy(PO3)4 were isolated from the reaction mixture by washing with hot water.

Refinement top

The distances between dysprosium atoms and the highest peak and the deepest hole are respectively, 1.39 Å and 0.78 Å.

Computing details top

Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO/SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. : The asymmetric unit of LiDy(PO3)4 with anisotropic displacement parameters drawn at the 50% probability level.Symmetry code: (i)-x + 1, y, -z + 1.5.
[Figure 2] Fig. 2. : Projection of the structure of LiDy(PO3)4 along the b axis.
[Figure 3] Fig. 3. : The O-atom coordination around Dy and Li atoms showing the connection of DyO8 and LiO4 polyhedra. [Symmetry codes: (i)-x + 1, y, -z + 1.5; (ii)-x + 1, -y + 1, -z + 2; (iii)x, -y + 1, z - 1/2; (iv)x, y + 1, z; (v)-x + 1, y + 1, -z + 1.5.
[Figure 4] Fig. 4. : Structural arrangement of LiDy(PO3)4 along the 1 0 1 direction.
lithium dysprosium polyphosphate top
Crystal data top
LiDy(PO3)4F(000) = 900
Mr = 485.32Dx = 3.646 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 1631 reflections
a = 16.269 (1) Åθ = 0.7–27.9°
b = 7.0236 (3) ŵ = 9.24 mm1
c = 9.5781 (8) ÅT = 295 K
β = 126.106 (3)°Block, colourless
V = 884.24 (10) Å30.10 × 0.09 × 0.08 mm
Z = 4
Data collection top
Nonius KappaCCD
diffractometer
1021 independent reflections
Radiation source: fine-focus sealed tube858 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.080
ϕ & ω scansθmax = 27.7°, θmin = 3.6°
Absorption correction: analytical
(de Meulenaer & Tompa, 1965)
h = 2120
Tmin = 0.42, Tmax = 0.45k = 97
3313 measured reflectionsl = 129
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullPrimary atom site location: structure-invariant direct methods
R[F2 > 2σ(F2)] = 0.038Secondary atom site location: difference Fourier map
wR(F2) = 0.087 w = 1/[σ2(Fo2) + (0.0468P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.95(Δ/σ)max < 0.001
1021 reflectionsΔρmax = 2.26 e Å3
83 parametersΔρmin = 2.13 e Å3
Crystal data top
LiDy(PO3)4V = 884.24 (10) Å3
Mr = 485.32Z = 4
Monoclinic, C2/cMo Kα radiation
a = 16.269 (1) ŵ = 9.24 mm1
b = 7.0236 (3) ÅT = 295 K
c = 9.5781 (8) Å0.10 × 0.09 × 0.08 mm
β = 126.106 (3)°
Data collection top
Nonius KappaCCD
diffractometer
1021 independent reflections
Absorption correction: analytical
(de Meulenaer & Tompa, 1965)
858 reflections with I > 2σ(I)
Tmin = 0.42, Tmax = 0.45Rint = 0.080
3313 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.03883 parameters
wR(F2) = 0.0870 restraints
S = 0.95Δρmax = 2.26 e Å3
1021 reflectionsΔρmin = 2.13 e Å3
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.

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Dy10.50000.79714 (6)0.75000.01295 (18)
P10.36225 (14)0.5523 (2)0.8849 (2)0.0108 (4)
P20.35333 (14)0.1513 (3)0.8039 (2)0.0124 (4)
O10.3870 (4)0.7158 (6)0.8178 (7)0.0148 (11)
O20.4353 (4)0.5025 (7)1.0727 (6)0.0142 (10)
O30.2555 (4)0.5780 (7)0.8535 (7)0.0141 (11)
O40.3421 (4)0.3778 (7)0.7655 (6)0.0169 (11)
O50.4287 (4)0.0852 (7)0.7730 (7)0.0147 (10)
O60.3726 (4)0.1159 (6)0.9727 (6)0.0180 (12)
Li0.50000.292 (2)0.75000.012 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Dy10.0130 (3)0.0101 (3)0.0150 (3)0.0000.0078 (2)0.000
P10.0103 (9)0.0098 (9)0.0115 (9)0.0003 (6)0.0059 (8)0.0008 (6)
P20.0106 (10)0.0115 (9)0.0123 (9)0.0008 (7)0.0053 (8)0.0007 (7)
O10.016 (3)0.013 (3)0.014 (3)0.002 (2)0.008 (2)0.0012 (19)
O20.008 (3)0.014 (2)0.016 (3)0.0022 (19)0.004 (2)0.001 (2)
O30.007 (3)0.017 (3)0.018 (3)0.0056 (19)0.007 (2)0.006 (2)
O40.023 (3)0.012 (3)0.012 (2)0.004 (2)0.008 (2)0.0057 (19)
O50.015 (3)0.016 (2)0.020 (3)0.0014 (19)0.014 (2)0.0011 (19)
O60.027 (3)0.008 (2)0.019 (3)0.003 (2)0.013 (3)0.0008 (19)
Li0.015 (9)0.004 (8)0.023 (9)0.0000.015 (8)0.000
Geometric parameters (Å, º) top
Dy1—O6i2.288 (5)P2—O3vi1.589 (5)
Dy1—O6ii2.288 (5)P2—O41.619 (5)
Dy1—O12.352 (5)P2—Li2.896 (5)
Dy1—O1iii2.352 (5)O2—Lii1.992 (11)
Dy1—O5iv2.406 (5)O2—Dy1i2.513 (5)
Dy1—O5v2.406 (5)O3—P2vii1.589 (5)
Dy1—O2ii2.513 (5)O5—Li1.951 (11)
Dy1—O2i2.513 (5)O5—Dy1viii2.406 (5)
Dy1—Liv3.476 (14)O6—Dy1i2.288 (5)
Dy1—Li3.548 (14)Li—O5iii1.951 (11)
P1—O11.483 (5)Li—O2i1.992 (11)
P1—O21.500 (5)Li—O2ii1.992 (11)
P1—O41.573 (5)Li—P2iii2.896 (5)
P1—O31.589 (5)Li—P1i3.035 (5)
P1—Lii3.035 (5)Li—P1ii3.035 (5)
P2—O61.475 (5)Li—Dy1viii3.476 (14)
P2—O51.495 (5)
O6i—Dy1—O6ii149.0 (2)O3vi—P2—O4100.9 (3)
O6i—Dy1—O193.73 (18)O6—P2—Li126.0 (2)
O6ii—Dy1—O193.71 (19)O3vi—P2—Li121.1 (2)
O6i—Dy1—O1iii93.71 (19)O4—P2—Li67.6 (3)
O6ii—Dy1—O1iii93.73 (18)P1—O1—Dy1139.8 (3)
O1—Dy1—O1iii151.9 (2)P1—O2—Lii120.0 (4)
O6i—Dy1—O5iv74.10 (17)P1—O2—Dy1i136.6 (3)
O6ii—Dy1—O5iv79.93 (18)Lii—O2—Dy1i103.3 (3)
O1—Dy1—O5iv136.63 (17)P1—O3—P2vii134.3 (4)
O1iii—Dy1—O5iv71.43 (16)P1—O4—P2130.8 (3)
O6i—Dy1—O5v79.93 (18)P2—O5—Li113.7 (4)
O6ii—Dy1—O5v74.10 (17)P2—O5—Dy1viii140.9 (3)
O1—Dy1—O5v71.43 (16)Li—O5—Dy1viii105.4 (3)
O1iii—Dy1—O5v136.63 (17)P2—O6—Dy1i133.6 (3)
O5iv—Dy1—O5v65.5 (2)O5—Li—O5iii83.7 (6)
O6i—Dy1—O2ii137.74 (17)O5—Li—O2i119.6 (2)
O6ii—Dy1—O2ii72.95 (15)O5iii—Li—O2i125.8 (2)
O1—Dy1—O2ii84.22 (17)O5—Li—O2ii125.8 (2)
O1iii—Dy1—O2ii72.18 (16)O5iii—Li—O2ii119.6 (2)
O5iv—Dy1—O2ii132.43 (17)O2i—Li—O2ii87.2 (6)
O5v—Dy1—O2ii137.20 (17)O5—Li—P228.19 (15)
O6i—Dy1—O2i72.95 (15)O5iii—Li—P2111.9 (5)
O6ii—Dy1—O2i137.74 (17)O2i—Li—P299.89 (18)
O1—Dy1—O2i72.18 (16)O2ii—Li—P2108.8 (2)
O1iii—Dy1—O2i84.22 (17)O5—Li—P2iii111.9 (5)
O5iv—Dy1—O2i137.20 (17)O5iii—Li—P2iii28.19 (15)
O5v—Dy1—O2i132.43 (17)O2i—Li—P2iii108.8 (2)
O2ii—Dy1—O2i66.2 (2)O2ii—Li—P2iii99.89 (18)
O6i—Dy1—Liv74.52 (12)P2—Li—P2iii140.1 (5)
O6ii—Dy1—Liv74.52 (12)O5—Li—P1i102.86 (18)
O1—Dy1—Liv104.06 (11)O5iii—Li—P1i108.3 (2)
O1iii—Dy1—Liv104.06 (11)O2i—Li—P1i25.34 (15)
O5iv—Dy1—Liv32.77 (12)O2ii—Li—P1i112.5 (5)
O5v—Dy1—Liv32.77 (12)P2—Li—P1i92.53 (5)
O2ii—Dy1—Liv146.88 (11)P2iii—Li—P1i101.64 (5)
O2i—Dy1—Liv146.88 (11)O5—Li—P1ii108.3 (2)
O6i—Dy1—Li105.48 (12)O5iii—Li—P1ii102.86 (18)
O6ii—Dy1—Li105.48 (12)O2i—Li—P1ii112.5 (5)
O1—Dy1—Li75.94 (11)O2ii—Li—P1ii25.34 (15)
O1iii—Dy1—Li75.94 (11)P2—Li—P1ii101.64 (5)
O5iv—Dy1—Li147.23 (12)P2iii—Li—P1ii92.53 (5)
O5v—Dy1—Li147.23 (12)P1i—Li—P1ii137.8 (5)
O2ii—Dy1—Li33.12 (11)O5—Li—Dy1viii41.9 (3)
O2i—Dy1—Li33.12 (11)O5iii—Li—Dy1viii41.9 (3)
Liv—Dy1—Li180.000 (5)O2i—Li—Dy1viii136.4 (3)
O1—P1—O2118.3 (3)O2ii—Li—Dy1viii136.4 (3)
O1—P1—O4106.4 (3)P2—Li—Dy1viii70.0 (3)
O2—P1—O4111.6 (3)P2iii—Li—Dy1viii70.0 (3)
O1—P1—O3112.1 (3)P1i—Li—Dy1viii111.1 (2)
O2—P1—O3105.0 (3)P1ii—Li—Dy1viii111.1 (2)
O4—P1—O3102.4 (3)O5—Li—Dy1138.1 (3)
O1—P1—Lii90.9 (3)O5iii—Li—Dy1138.1 (3)
O4—P1—Lii144.5 (3)O2i—Li—Dy143.6 (3)
O3—P1—Lii99.2 (2)O2ii—Li—Dy143.6 (3)
O6—P2—O5119.7 (3)P2—Li—Dy1110.0 (3)
O6—P2—O3vi112.5 (3)P2iii—Li—Dy1110.0 (3)
O5—P2—O3vi107.3 (3)P1i—Li—Dy168.9 (2)
O6—P2—O4109.7 (3)P1ii—Li—Dy168.9 (2)
O5—P2—O4104.9 (3)Dy1viii—Li—Dy1180.0
Symmetry codes: (i) x+1, y+1, z+2; (ii) x, y+1, z1/2; (iii) x+1, y, z+3/2; (iv) x+1, y+1, z+3/2; (v) x, y+1, z; (vi) x+1/2, y1/2, z+3/2; (vii) x+1/2, y+1/2, z+3/2; (viii) x, y1, z.

Experimental details

Crystal data
Chemical formulaLiDy(PO3)4
Mr485.32
Crystal system, space groupMonoclinic, C2/c
Temperature (K)295
a, b, c (Å)16.269 (1), 7.0236 (3), 9.5781 (8)
β (°) 126.106 (3)
V3)884.24 (10)
Z4
Radiation typeMo Kα
µ (mm1)9.24
Crystal size (mm)0.10 × 0.09 × 0.08
Data collection
DiffractometerNonius KappaCCD
diffractometer
Absorption correctionAnalytical
(de Meulenaer & Tompa, 1965)
Tmin, Tmax0.42, 0.45
No. of measured, independent and
observed [I > 2σ(I)] reflections
3313, 1021, 858
Rint0.080
(sin θ/λ)max1)0.655
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.087, 0.95
No. of reflections1021
No. of parameters83
Δρmax, Δρmin (e Å3)2.26, 2.13

Computer programs: COLLECT (Nonius, 1998), DENZO/SCALEPACK (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 1999).

 

Acknowledgements

This work was supported by the Ministry of Higher Education, Scientific Research and Technology of Tunisia.

References

First citationAverbuch-Pouchot, M. T. & Bagieu Beucher, M. (1987). Z. Anorg. Allg. Chem. 552, 171–180.  CrossRef CAS Web of Science Google Scholar
First citationBen Zarkouna, E. & Driss, A. (2004). Acta Cryst. E60, i102–i104.  Web of Science CrossRef IUCr Journals Google Scholar
First citationBen Zarkouna, E., Férid, M. & Driss, A. (2005). Mater. Res. Bull. 40, 198–1992.  Web of Science CrossRef Google Scholar
First citationBen Zarkouna, E., Horchani-Naifer, K., Férid, M. & Driss, A. (2007). Acta Cryst. E63, i1–i2.  Web of Science CrossRef IUCr Journals Google Scholar
First citationBrandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationChehimi-Moumen, F. & Férid, M. (2007). Acta Cryst. E63, i129–i130.  Web of Science CrossRef IUCr Journals Google Scholar
First citationDurif, A. (1995). Crystal Chemistry of Condensed Phosphates. New York: Plenum Press.  Google Scholar
First citationEttis, H., Naili, H. & Mhiri, T. (2006). J. Solid State Chem. 179, 3107–3113.  Web of Science CrossRef CAS Google Scholar
First citationFérid, M. (2006). Etude des propriétés cristallochimiques et physiques de phosphates condensés de terres rares. Paris: Publibook.  Google Scholar
First citationHashimoto, N., Takada, Y., Sato, K. & Ibuki, S. (1991). J. Lumin. 48–49, 893–897.  CrossRef CAS Web of Science Google Scholar
First citationHong, H. Y. P. (1975). Mater. Res. Bull. 10, 635–640.  CrossRef CAS Web of Science Google Scholar
First citationHorchani, K., Gâcon, J. C., Férid, M., Trabelsi-Ayadi, M., Krachni, G. K. & Liu, G. K. (2003). Opt. Mater. 24, 169–174.  Web of Science CrossRef CAS Google Scholar
First citationKoizumi, H. (1976). Acta Cryst. B32, 266–268.  CrossRef CAS IUCr Journals Web of Science Google Scholar
First citationLiu, J.-C. & Li, D.-Y. (1983). Acta Phys. Sinica, 32, 786–790.  CAS Google Scholar
First citationMeulenaer, J. de & Tompa, H. (1965). Acta Cryst. 19, 1014–1018.  CrossRef IUCr Journals Web of Science Google Scholar
First citationNonius (1998). COLLECT. Nonius BV, Delft, The Netherlands.  Google Scholar
First citationOtwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationYamada, T., Otsuka, K. & Nakano, J. (1974). J. Appl. Phys. 45, 5096–5097.  CrossRef CAS Web of Science Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds