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Structure of the borate Li14Be5B(BO3)9
Abstract
The new compound Li14Be5B(BO3)9 has been synthesized and structurally characterized by single-crystal X-ray methods. It crystallizes in the hexagonal system (space group P6(3)/m, Z = 2) in a cell of dimensions a = 7.730(2) angstrom, c = 18.853(2) angstrom, and V = 975.5(3) angstrom3. The model has been refined with 1725 unique reflections to the final residuals R = 0.048 and R(w) = 0.067. LiO3 and BO3 triangles, LiO4 and BeO4 tetrahedra, and LiO6 trigonal prisms join by sharing vertices to form a unique, dense three-dimensional structure.
Beryllium (Be) has high ionization energy (9.32 eV) with the greatest degree of covalency in the group IIA elements, and BeO4 tetrahedra (and BeO3 triangles) with covalent character are generally presented in beryllates. An unprecedented BeO6 trigonal prism with ultralong Be−O bonds as well as a BeO4 common tetrahedron is discovered in a new deep ultraviolet crystal Li13BeBe6B9O27 (LBeBBO) with a∞2 [Be6B9O33] double-layer framework. The BeO6 unit and its bond character are verified by an isostructural crystal Li13(Mg0.45Be0.55)Be6B9O27, while the orbital theory and charge density difference further clarify the ionic character of the BeO6 unit. Phonon dispersion confirms the structural stability of LBeBBO.
Li3K3Y7(BO3)9 was prepared by high-temperature solid state synthesis at 900 °C in a platinum crucible from lithium carbonate, potassium carbonate, boric acid, and yttrium(III) oxide. The compound crystallizes in the orthorhombic space group Pca21 (no. 29) (Z = 4). The structure was refined from single-crystal X-ray diffraction data: a = 20.743(8), b = 6.387(4), c = 17.474(4) Å, V = 2315.2(2) ų, R1 = 0.0473, and wR2 = 0.0637 for all data. The crystal structure of Li3K3Y7(BO3)9 consists of isolated BO3 groups forming [Li3B4O21] units in combination with LiO6 octahedra in the ac plane, which are interconnected to each other by additional planar BO3 groups. The Y³⁺ and K⁺ cations are arranged in layers along the a-axis.
A new lithium zincoborate Li6Zn3(BO3)4 has been successfully prepared via a high-temperature solution method, which is composed of the LiO4 and ZnO4 tetrahedra, and nearly coplanar BO3 units. The face-sharing LiO4 configuration was found in the title compound, and the comparisons of Li-O configurations were systemically investigated among all the Li-containing borates. Interestingly, Li6Zn3(BO3)4 has two reversible phase transitions at about 341 and 706 oC, which implies that Li6Zn3(BO3)4 is a potential candidate for phase change material. The in situ high-temperature X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis were used to verify the two reversible phase transitions. The linear optical properties were detailed researched using the ab initio density functional theory (DFT) method.
This document is part of Subvolume A3 'Structure Types. Part 4: Space Groups (189) P-62m- (174) P-6' of Volume 43 'Crystal Structures of Inorganic Compounds' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains the standardized crystallographic data set of Li14Be5B(BO3)9 representing the structure type Li14(Be0.83B0.17)6[BO3]9. Associated space group: (176) P63/m Contained elements: B-Be-Li-O
A new strontium beryllium borate fluoride, Sr3[(BexB1-x)3B3O10][Be(O1-xFx)3] x = 0.30 (SBBOF), designed to be used in the deep-UV nonlinear optical (NLO) application, was grown by the spontaneous crystallization of a molten flux of SrO-B2O3-LiF. It crystallizes in the space group R3m (No. 160) with the following unit cell dimensions: a = 10.3179(11) Å, c= 8.3958(13) Å, V = 774.1(2) Å3 and Z = 3. SBBOF consists of [(BexB1-x)3B3O10] anionic groups and isolated [Be(O1-xFx)3] planar groups. Importantly, a new strategy to improve the birefringence was introduced by changing the local configuration of isolated structural units from trigonal pyramids to planar triangles. UV-Vis diffuse reflectance spectroscopy indicates that the short-wavelength absorption edge of SBBOF is below 200 nm. The band structure and refractive index were calculated. Second harmonic generation (SHG) was measured using the Kurtz and Perry technique, which showed that SBBOF is a phase-matchable material in both visible and UV regions, and its measured SHG coefficient is 2.2 times as large as that of d36 (KDP) at 1064nm.
Crystal design and growth of huntite-type and alkaline beryllium borates used for UV and deep-UV frequency conversion are summarized. A series borates crystallizing in the trigonal-huntite structure, ReM3(BO3)4 (Re = La, Ga, Y, Lu; M = Y, Lu, Sc, Ga, Al), has been discovered through structural design with respect to the size tuning on trigonal prism or/and octahedral site in the structure. The structural, optical, and chemical–physical properties are detailed. They all have large NLO coefficients, moderate birefringence for UV phase matching, and robust chemical and physical properties. The NLO coefficients of those containing Bi are larger due to the contribution from the lone-pair electron of Bi, while the UV cutoff of these crystals is redshift for about 100 nm. The systematical synthesis of a series of new alkaline beryllium borates with the stoichiometry NaBeB3O6, ABe2B3O7 (A = K, Rb), and Na2CsBe6B5O15 in order to obtain deep-UV NLO crystals containing new beryllium borate anionic groups or framework was presented. A new beryllium borate anionic group [Be2B3O11]9− was found in the structure of NaBeB3O6 and α-KBe2B3O7. β-KBe2B3O7, γ-KBe2B3O7, RbBe2B3O7, and Na2CsBe6B5O15 consist of 2D alveolate beryllium borate network [Be2BO5]∞. Furthermore, the adjacent [Be2BO5]∞ layers in these compounds were connected by covalent bonds.
The phase diagram in the Li2O-BeO-B2O3 system has been systematically investigated by the methods of visual polythermal analysis, spontaneous crystallization, and X-ray diffraction. Three new alkaline beryllium borates, namely, LiBeBO3, Li6Be3B4O12, and Li8Be5B6O18, were synthesized with molten fluxes based on Li2O-B2O3 solvent in this system. All of the materials are centrosymmetric. The similarity of the fundamental building block of the title compounds has been compared. Thermal analysis and powder XRD studies were applied to determine phase relation and their incongruent melting behavior. The UV-vis diffuse reflectance spectroscopy demonstrated that the UV cutoff edges of the aforementioned materials are all below 200 nm.
The combination of Pb2+ cations with lone-pair electrons and F- anions with the largest electronegativity into the carbonate generates a new nonlinear optical material, CsPbCO3F, with the largest powder SHG response among carbonates of about 13.4 times that of KDP (KH2PO4), and transparency over the near-UV to middle-IR region. The optical characterization of the compound indicates that it is phase matchable. Its crystal structure exhibits the stacking of [CsF]∞ and [Pb(CO3)]∞ layers, and the coplanar alignment of [CO3] triangles which are oriented in the same direction. Yet the Pb2+ cation has an inert or non-stereoactive lone-pair, as indicated by its more spherical shape. Theoretical calculations confirm that the extremely large SHG efficiency indeed originates from enhancement via p-π interaction between Pb2+ and [CO3]2- within the [Pb(CO3)] layers.
A new noncentrosymmetric lanthanum beryllium borate compound, LaBeB3O7, has been designed and synthesized by spontaneous crystallization with molten flux. In its crystal structure, boron and beryllium atoms are mutual disorder occupied and coordinated with four oxygen atoms forming XO4 tetrahedra (X = B, Be). The XO4 tetrahedra pile up with each other in the alignment toward the c-axis and build up BeB5O18 six-membered rings along the ab plane with La cations located inside the ring channels. Its structure is isotypic to the SrB4O7. LaBeB3O7 melts congruently at 1100 °C and exhibits the short wavelength absorption edge at 220 nm. Second harmonic generation (SHG) on polycrystalline samples was measured using the Kurtz and Perry technique, which indicated that this compound is phase-matchable and the measured SHG coefficient was about 1–2 times that of KH2PO4 (KDP). Theoretical calculations were carried out to explain the increasing of birefringence in this crystal structure. Our preliminary results indicate that LaBeB3O7 is a promising NLO crystal.
The new lithium borate HP-LiB3O5 was synthesized under high-pressure/high-temperature conditions of 6GPa and 1050°C in a multianvil press with a Walker-type module. The compound crystallizes in the space group Pnma (no. 62) with the lattice parameters a=829.7(2), b=759.6(2), and c=1726.8(4)pm (Z=16). The high-pressure compound HP-LiB3O5 is built up from a three-dimensional network of BO4 tetrahedra and BO3 groups, which incorporates Li+ ions in channels along the b-axis. Band assignments of measured IR- and Raman spectra were done via quantum-mechanical calculations. Additionally, the thermal behavior of HP-LiB3O5 was investigated.
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SmNiAl4Ge2 crystallizes from molten Al containing Sm, Ni, and Ge. The compound crystallizes in the rhomohedral space group R3m with a = 4.1121(6) Å, c = 31.109(6) Å, and V = 455.5(1) Å3. The YNiAl4Ge2 analogue is also stable. The crystal structure consists of layers of [NiAl4Ge2]3- separated by monolayers of hexagonally close-packed Sm3+ ions. The Ni atoms are surrounded by eight Al atoms in the structure. Each Sm atom has an octahedral environment of six Ge atoms. The magnetism of SmNiAl4Ge2 is unusual, possibly reflecting the presence of geometrical spin frustration. The magnetization exhibits a well-defined hysteresis loop, without signs of ferromagnetism. It also exhibits irreversibility in the field-cooled and zero-field-cooled magnetization but without the typical characteristic spin glass behavior.
SmNiAl4Ge2 crystallizes from molten Al containing Sm, Ni, and Ge. The compound crystallizes in the rhomohedral space group R3m with a = 4.1121(6) Angstrom, c = 31.109(6) Angstrom, and V = 455.5(1) Angstrom(3). The YNiAl4Ge2 analogue is also stable. The crystal structure consists of layers of [NiAl4Ge2](3-) separated by monolayers of hexagonally close-packed Sm3+ ions. The Ni atoms are surrounded by eight Al atoms in the structure. Each Sm atom has an octahedral environment of six Ge atoms. The magnetism of SmNiAl4Ge2 is unusual, possibly reflecting the presence of geometrical spin frustration. The magnetization exhibits a well-defined hysteresis loop, without signs of ferromagnetism. It also exhibits irreversibility in the field-cooled and zero-field-cooled magnetization but without the typical characteristic spin glass behavior.
New compounds in the system RE-Al-Ge (RE=Tb, Gd, Ho) were prepared in molten aluminum. Large, (up to 5 mm) single crystals of new pseudo-binary phases GdAl3−xGex, (x=0.1), TbAl3−xGex, (x=0.3), and HoAl3−xGex, (x=0.2) were recovered in high yield. The crystal structures were refined by single crystal X-ray diffraction techniques, and found to vary as a function of rare-earth element. Thus, GdAl3−xGex crystallizes in the Ni3Sn structure type (P63/mmc) of GdAl3. For the TbAl3−xGex the BaPb3 structure type (R-3m) is adopted, as it is for TbAl3. In the case of HoAl3−xGex, the structure type of HoAl3 is not stabilized, and the compound crystallizes in the BaPb3 structure (R-3m). Crystal data: GdAl3−xGexa=6.3115(4) Å, c=4.6052(4) Å, V=158.87(2) Å3, P63/mmc (No. 194, Z=2); TbAl3−xGexa=6.1956(9) Å, c=21.025(4) Å, V=698.9(2) Å3, R-3m (No. 166, Z=9); HoAl3−xGexa=6.1579(10) Å, c=21.062(5) Å, V=691.7(2) Å3, R-3m (No. 166, Z=9). Charge transport properties indicate that these materials are good metallic conductors. At low temperatures they order antiferromagnetically, whereas above ∼50 K they are Curie–Weiss paramagnets. The temperature of maximum magnetic susceptibility (Tmax) is 5.93 K, 18.8 K, and 24.0 K for HoAl2.8Ge0.2, TbAl2.7Ge0.3, and GdAl2.9Ge0.1 respectively.
The synthesis and structure of the isostructural acentric compounds Sr(3)Be(2)B(5)O(12)(OH) (1) and Ba(3)Be(2)B(5)O(12)(OH) (2) are reported for the first time. These compounds crystallize in the space group R3m, and the unit cell parameters are a = 10.277(15) Å and c = 8.484(17) Å for 1 and a = 10.5615(15) Å and c = 8.8574(18) Å for 2. The structures consist of a network of [Be(2)B(4)O(12)(OH)] units interwoven with a network consisting of MO(9) polyhedra (M = Sr, Ba) and BO(3) triangles and exemplify how acentric building blocks such as [BO(3)](3-), [BO(4)](5-), and [BeO(4)](6-) can be especially suitable to build noncentrosymmetric long-range structures. Both networks are centered on the 3-fold rotation axis and present themselves in alternating fashion along [001]. Acentricity is imparted by the alignment of the polarities of BO(3) and BeO(4) environments. Infrared spectroscopy has been used to confirm the local geometries of B and Be, as well as the presence of hydroxide in the crystal structure. Another interesting feature of these compounds is the presence of disorder involving Be and B at the tetrahedral Be site. The degree of the disorder has been confirmed by observing a noticeable shortening of average Be-O bond distances.
A new series of alkaline beryllium borates NaBeB(3)O(6), alpha-KBe(2)B(3)O(7), beta-KBe(2)B(3)O(7), gamma-KBe(2)B(3)O(7), and RbBe(2)B(3)O(7) were synthesized by spontaneous crystallization with molten fluxes based on A(2)O-B(2)O(3) (A = Na, K, Rb) solvent. For KBe(2)B(3)O(7), three polymorphous phases were found and are referred to as alpha-, beta-, and gamma-KBe(2)B(3)O(7) relative to their crystallization temperature from high to low. All of the materials are noncentrosymmetric except alpha-KBe(2)B(3)O(7). NaBeB(3)O(6) and alpha-KBe(2)B(3)O(7) consist of a new anionic group [Be(2)B(3)O(11)](9-), which is similar to a naphthalene molecule that is rarely found in inorganic matter. beta-KBe(2)B(3)O(7), gamma-KBe(2)B(3)O(7), and RbBe(2)B(3)O(7) consist of 2D alveolate beryllium borate layers [Be(2)BO(5)](infinity), which are connected by strong covalent bonds. The UV-vis diffuse reflectance spectroscopy on powder samples indicated that the short-wavelength absorption edges of noncentrosymmetric materials are all below 200 nm. Second-harmonic generation (SHG) on powder samples was measured using the Kurtz and Perry technique, which indicated that NaBeB(3)O(6), beta-KBe(2)B(3)O(7), gamma-KBe(2)B(3)O(7), and RbBe(2)B(3)O(7) are all phase matchable materials, and their measured SHG coefficients were approximately 1.60, 0.75, 0.68, and 0.79 times as large as that of d(36) (KDP), respectively.
The compounds RE4FeGa(12-x)Ge(x) (RE = Sm, Tb) were discovered in reactions employing molten Ga as a solvent at 850 degrees C. However, the isostructural Y4FeGa(12-x)Ge(x) was prepared from a direct combination reaction. The crystal structure is cubic with space group Imm, Z = 2, and a = 8.657(4) A and 8.5620(9) A for the Sm and Tb analogues, respectively. Structure refinement based on full-matrix least squares on F(o)2 resulted in R1 = 1.47% and wR2 = 4.13% [I > 2(I)] for RE = Sm and R1 = 2.29% and wR2 = 7.12% [I > 2(I)] for RE = Tb. The compounds crystallize in the U4Re7Si6 structure type, where the RE atoms are located on 8c (1/4, 1/4, 1/4) sites and the Fe atoms on 2a (0, 0, 0) sites. The distribution of Ga and Ge in the structure, investigated with single-crystal neutron diffraction on the Tb analogue, revealed that these atoms are disordered over the 12d (1/4, 0, 1/2) and 12e (x, 0, 0) sites. The amount of Ga/Ge occupying the 12d and 12e sites refined to 89(4)/11 and 70(4)/30%, respectively. Transport property measurements indicate that these compounds are metallic conductors. Magnetic susceptibility measurements and Mössbauer spectroscopy performed on the Tb analogue show a nonmagnetic state for Fe, while the Tb atoms carry a magnetic moment corresponding to a mu(eff) of 9.25 mu(B).
Single crystals of a new rubidium beryllium borate, RbBe4(BO3)3, have been obtained by spontaneous nucleation from a high-temperature melt. This new orthorhombic (Pnma) structure type contains [Be2BO4]- rings, made of two BeO4 tetrahedra and one BO3 triangle, which constitute the basic structural units. The m plane runs through the B and one of the O atoms and intersects the ring. These rings form chains in the a direction, which are connected in the b and c directions to form zeolite-type cages in which the Rb+ cations are located, at sites of m symmetry.
The compound SrBe 2(BO 3) 2
crystallizes in the monoclinic space group P2 1/ n in a cell
of dimensions a = 9.247(1) Å, b = 4.492(2) Å, c = 11.561(1)
Å, and β = 112.17(1)° with Z = 4. Least-squares
refinement affords the final residuals R = 0.034 and Rw =
0.045. The structure consists of layers of composition [Be
2(BO 3) 2] 2- that are
interleaved by Sr atoms. Each layer contains two crystallographically
inequivalent Be and B atoms; the Be atoms occupy distorted O tetrahedra
while the B atoms occupy distorted triangular planar environments. Two
Be atoms of one type share two O atoms to form a dimer of edge-shared
tetrahedra. The Sr atom occupies a distorted monocapped 8-coordinate
site.
The structure of the compound Ba2LiB5O10 has been established by single-crystal X-ray methods. It crystallizes in the monoclinic space group P21/m in a cell of dimensions a = 4.414(1), b = 14.576(2), , and β = 104.26(2)° with Z = 2. Refinement from 2373 independent reflections affords the final residuals R = 0.021 and RW = 0.042. The structure exhibits a unique one-dimensional polyborate anion built from two crystallographically independent BO3 groups and a distinct BO4 group that share vertices. The polyanions are bridged by a Li atom occupying a distorted tetrahedral site and a Ba atom occupying an irregular eightfold coordinate site.
Indium lithium distrontium decaoxotetraborate, InLiSr2B4O10, M(r) = 500.23, monoclinic, P2(1)/n, a = 12.637 (1), b = 5.251 (1), c = 13.748 (1) angstrom, beta = 116.94 (1)degrees, V = 813.2 (4) angstrom3, Z = 4, D(x) = 4.085 g cm-3, lambda(Mo Kalpha) = 0.71069 angstrom, mu = 154.94 cm-1, F(000) = 912, T = 298 K, R = 0.060 for 1731 reflections having F(o)2 greater-than-or-equal-to 3sigma(F(o)2). The structure is composed of a three-dimensional SrO7 polyhedral framework with hexacoordinated In and penta-coordinated Li atoms in interstitial sites. Marked deviations from orthogonality in the distorted octahedral InO6 group include O3-In-O9, 80.8 (3), O1-In-O9, 80.8 (3), O1-In-O9, 84.6 (3) and O2-In-O9, 97.0 (3)-degrees. Pyroborate groups form layers extending in the plane (101BAR).
Beryllium calcium diborate, CaBeB2O5, M(r) = 150.71, monoclinic, P2(1)/n, a = 5.167 (2), b = 3.756 (2), c = 17.160 (2) angstrom, beta = 98.12 (2)degrees, V = 329.7 (2) angstrom3, Z = 4, D(x) = 3.036 g cm-3 lambda(Mo Kalpha) = 0.71069 angstrom, mu = 17.38 cm-1, F(000) = 296, T = 298 K, R = 0.039 for 508 reflections having F(o)2 greater-than-or-equal-to 3sigma(F(o)2). The structure is constructed from two intermingled networks - a CaO9 polyhedral system and a beryllium borate complex constructed from four-coordinate Be and three- and four-coordinate B atoms. The extended beryllium borate complex results from the unique condensation of six-membered rings containing the triangular and distorted tetrahedral beryllate and borate groups.
Absorption effects usually present the most serious source of systematic error in the determination of structure factors from single-crystal X-ray diffraction measurements if the crystal is not ground to a sphere or cylinder. A novel method is proposed for the correction of these effects for data collected on a diffractometer. The method works from the premise that the manifestation of systematic errors due to absorption, unlike most other sources of systematic error, will not be evenly distributed through reciprocal space, but will be localized. A Fourier series in the polar angles of the incident and diffracted beam paths is used to model an absorption surface for the difference between the observed and calculated structure factors. Knowledge of crystal dimensions or linear absorption coefficient is not required, and the method does not necessitate the measurement of azimuthal scans or any extra data beyond the unique set. Moreover, application of the correction is not dependent upon the Laue symmetry of the crystal or the geometry of the diffractometer. The method is compared with other commonly used corrections and results are presented which demonstrate its potential.
The new compound BaBeâ(BOâ)â is readily prepared by a solid-state reaction. It crystallizes in the orthorombic space group Fddd (Z = 8) in a cell of dimensions a = 11.725(2) â«, b = 13.004(1) â«, c = 6.286(1), â«, and V = 958.4(2) â«Â³. Residuals from least-squares refinement with 1689 unique reflections are R = 0.024 and R{sub w} = 0.042. The structure is composed of two interpretrating polyhedral frameworks. A beryllium-borate matrix containing dimers of edge-sharing Be-centered tetrahedra linked via regular, planar triangular BOâ groups is penetrated by a framework constructed from Ba-centered dodecahedra sharing multiple edges. The optical emission characteristics of samples doped with the ions Eu{sup 2+} and Eu{sup 3+} are reported.
New compounds of formula LiBa3M3Ti5O21 (M = Nb, Ta, Sb) have been obtained by insertion of lithium in the lattice of Ba3M4Ti4O21 (M = Nb, Ta, Sb). They crystallize in the hexagonal system with a filled cage structure of A3M8O21 type. Crystallographic studies by X-ray and neutron diffraction show a partial order between TiIV and MV ions (Nb, Ta, Sb) in the octahedral sites of the cell (space group P63/mcm).
A comprehensive X-ray study of lithium niobate at room temperature has been made, prompted by the recently discovered excellent nonlinear optical properties and unusual ferroelectric behavior of this crystal. Lithium niobate is rhombohedral with lattice constants aH = 5·14829 ± 0·00002, cH = 13·8631 ± 0·0004 Å and space group R3c(C3v6), at 23°C. The cry structure has been solved without reference to earlier work, and refined using three-dimensional Patterson and Fourier series in addition to the method of least squares. The integrated intensities of 247 independent, 486 dispersively-unequal hkl and khl, reflections in all forms within a hemisphere of Å−1 were measured with PEXRAD. The final agreement factor was 0.038. The absolute configuration of the atomic arrangement has been established, and for the first time in a ferroelectric crystal, related to the sense of the ferroelectric polarization, as determined by pyroelectric measurement followed by etching. The oxygen atoms are arranged in planar sheets, forming a network of distorted octahedra. At 24°C, the sequence of octahedra along the cH−axis is, Nb, vacancy, Li, Nb, vacancy, Li. The Nb octahedra have two Nb-O distances, of 1·889 ± 0·003 and 2·112 ± 0·004 Å. The Li octahedra also have two metal-oxygen distances, Li-O being 2·068 ± 0·011 and 2·238 ± 0·023 Å. There is metallic contact between Nb and Li, with puckered sheets of Nb and Li atoms 3.054 Å apart normal to cH connected by 3.010 Å contacts parallel to cH.The thermal vibrations of all atoms are isotropic and correspond to a characteristic Debye temperature of 503°K.