A5RE4X[TO4]4crystal growth and photoluminescence. Fluoride flux synthesis of sodium and potassium rare earth silicate oxyfluorides

Latshaw, Allison M.; Wilkins, Branford O.; Hughey, Kendall D.; Yeon, Jeongho; Williams, Derek E.; Tran, T. Thao; Halasyamani, P. Shiv; Loye, Hans‐Conrad zur

doi:10.1039/c5ce00671f

Cited by 24 publications

(18 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While one may expect to make radically different sheet structures using Cl − due to the commonly terminal nature and large size of this anion, causing it to stick out of the plane of the sheet, as seen in K 4 U 5 O 16 Cl 2 and Cs 5 U 7 O 22 Cl 3 (Read et al, 2014), the inclusion of F − could lead to new sheet structures or to those already observed in oxides. This arises partially due to the similarity in size of O and F, and examples can be seen in the existence of both rare earth oxides and oxyfluorides that adopt the prominent apatite structure (Latshaw et al, 2014, 2015). In rare earth silicates, the coordination of the rare earth to F limits the available connectivity to the silicate tetrahedra, as SiO 3 F tetrahedra are unreported in crystalline structures (Leinenweber et al, 2005; Morrison et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Observation of the Same New Sheet Topology in Both the Layered Uranyl Oxide-Phosphate Cs11[(UO2)12(PO4)3O13] and the Layered Uranyl Oxyfluoride-Phosphate Rb11[(UO2)12(PO4)3O12F2] Prepared by Flux Crystal Growth

et al. 2019

Self Cite

View full text Add to dashboard Cite

Single crystals of four new layered uranyl phosphates, including three oxyfluoride-phosphates, were synthesized by molten flux methods using alkali chloride melts, and their structures were determined by single-crystal X-ray diffraction. Cs 11 [(UO 2 ) 12 (PO 4 ) 3 O 13 ] ( 1 ) and Rb 11 [UO 2 ) 12 (PO 4 ) 3 O 12 F 2 ] ( 2 ) contain uranyl phosphate layers exhibiting a new sheet topology that can be related to that of β-U 3 O 8 , while Cs 4.4 K 0.6 [(UO 2 ) 6 O 4 F(PO 4 ) 4 (UO 2 )] ( 3 ) and Rb 4.4 K 0.6 [(UO 2 ) 6 O 4 F(PO 4 ) 4 (UO 2 )] ( 4 ) contain layers of a known isomer of the prominent phosphuranylite topology. The location of the fluorine in structures 2 - 4 is discussed using bond valence sums. First principles calculations were used to explore why a pure oxide structure is obtained for the Cs containing phase ( 1 ) and in contrast an oxyfluoride phase for the Rb containing phase ( 2 ). Ion exchange experiments were performed on 1 and 2 and demonstrate the ability of these structures to exchange approximately half of the parent alkali cation with a target alkali cation in an aqueous concentrated salt solution. Optical measurements were performed on 1 and 2 and the UV-vis and fluorescence spectra show features characteristic of the uranyl group.

show abstract

Section: Introductionmentioning

confidence: 99%

Observation of the Same New Sheet Topology in Both the Layered Uranyl Oxide-Phosphate Cs11[(UO2)12(PO4)3O13] and the Layered Uranyl Oxyfluoride-Phosphate Rb11[(UO2)12(PO4)3O12F2] Prepared by Flux Crystal Growth

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…Fluoride fluxes have been demonstrated to readily dissolve starting material oxides, including rare earth oxides, silicon dioxide, and germanium oxide. Since it is known that rare earth silicate oxides and oxyfluorides have been grown out of alkali fluoride fluxes, these fluxes represent good choices when trying to grow new rare earth tetragen oxyfluorides [2,[4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

“…The previously reported silicon analogues of the title compounds, Nd, Sm-Tm), were studied for their magnetic, luminescent, and SHG properties [4,6]. It was determined that in the oxyhydroxide analogues, the Tb analogue ordered antiferromagnetically, the Eu, Gd, and Tb members luminesce with fluorescence quantum yields from 2 -21 %, and second harmonic generation (SHG) was not observed.…”

Section: Introductionmentioning

confidence: 99%

A5RE4X[TO4]4 crystal growth: Fluoride flux synthesis of Na5Ln4F[GeO4]4 (Ln=Pr, Nd), the first quaternary germanate oxyfluorides

Latshaw

Wilkins

Morrison

et al. 2016

Journal of Solid State Chemistry

Self Cite

View full text Add to dashboard Cite

Crystals of Na 5 Pr 4 F[GeO 4 ] 4 and Na 5 Nd 4 F[GeO 4 ] 4 were synthesized using a eutectic sodium fluoride, sodium chloride flux. Both compounds crystallize in the tetragonal space group I-4 with lattice parameters of a = 12.1173(4) Å and c = 5.6795(2) Å (Pr) and of a = 12.0642(17) Å and c = 5.6674(11) Å (Nd). The structure of the reported compounds is three-dimensional with face and corner sharing lanthanide polyhedra which edge and corner share with isolated germanium tetrahedra. These novel compositions represent the first example of quaternary germanium containing oxyfluorides.

show abstract

“…Silicates are an expansive class of extended structures that are based on linked SiO4 tetrahedral building blocks and that encompass many diverse compositions [1][2][3][4][5][6] including numerous examples of complex rare earth containing silicate structures. The presence of rare earth elements in the silicate structure can lead to interesting optical [5,[7][8][9][10] and magnetic [4,[11][12][13][14] properties. Furthermore, a unique feature of the rare earth silicates is the existence of a series of structural analogs and, at times, new structure types when a rare earth cation size limit is reached above or below the point at which a given structure ceases to form.…”

Section: Introductionmentioning

confidence: 99%

“…The synthesis of new silicates can be accomplished by a number of methods, including solid-state reactions to obtain polycrystalline samples and solution based routes to obtain single crystals. For the latter case fluoride containing fluxes have been shown to be very effective means of dissolving SiO2 as well as rare earth oxides to produce rare earth containing compositions [12,17,18]. When using fluoride-containing fluxes with rare earths and silica, products are usually rare earth silicate oxides or oxyfluorides.…”

Section: Introductionmentioning

confidence: 99%

Influence of rare earth cation size on the crystal structure in rare earth silicates, Na2RESiO4(OH) (RE = Sc, Yb) and NaRESiO4 (RE = La, Yb)

Latshaw

Wilkins

Chance

et al. 2016

Solid State Sciences

Self Cite

View full text Add to dashboard Cite

= 5. For n = 2-13, the transition or switch from weak (primarily dipole-dipole-type) inter-monomer interactions to a preference for polar covalent bonding occurs within n = 5-9. Thermodynamic evidence for this transition is provided. The results demonstrate a significant risk associated with crystal structure prediction from the ground up (i.e., based on bonding patterns in small clusters). The path from monomers through extended solids with increasing n is discussed to be associated with transitions in structure and bonding that are not anticipated by the bonding in small clusters. 2O3 with 98% H2SO4 (porcelain crucible, 230 C resp. 210 C, 5 d; cooling to 100 C at a rate of 2 C/h, 89 and 91% yield for the K and Cs compound, resp.). KSb(SO 4 ) 2 crystallizes in the monoclinic space group P2 1 /c (Z = 4, single crystal XRD), and CsSb(SO 4 ) 2 in the orthorhombic space group P2 1 2 1 2 1 (Z = 4). Both compounds show the Sb 3+ cations in a seesaw-type coordination of O atoms from different anions, but exhibit complex 2D and 1D linked anionic structures. The alkali cations are located between the layers or chains. The band gaps are estimated to be 4.64 eV for KSb(SO 4 ) 2 and 4.68 eV for CsSb (SO 4 -Eu 7 Cd 4 Sb 8-x As x (x = 2, 3, 4, and 5) solid solutions are prepared from the elements in a molten Sn flux (alumina crucible in evacuated silica tubes, 1. 600 C, 6 h; 2. 1000 C, 96 h; cooling to 600 C at a rate of 5 C/h). The title phases crystallizes in the I-centered monoclinic space group I2/m (Z = 4, single crystal XRD) and contain parallel double pentagonal tubes resulting from Cd-Pn (Pn: Sb, As) and Pn-Pn bonding. These double pentagons are formed through corner sharing of Cd-centered CdPn 4 tetrahedra and a Pn-Pn interaction of two adjacent CdPn 4 tetrahedra. Theoretical calculations predict that Sb-rich compounds should be metallic or semimetallic and that they should become more insulating as As levels increase. Members of the solid-solution order ferromagnetically between 5 and 6 K and exhibit electrical resistivities ranging from 0.57 (50 K) to 26 m·cm (300 K) which increase with As levels. -Single crystals of Na 2 ScSiO 4 (OH) (I) and Na 2 YbSiO 4 (OH) (II) are prepared by hydrothermal reaction of a 2:1 molar mixture of Na 2 SiO 3 and Sc 2 O 3 (Yb 2 O 3 ) in a NaOH based hydroflux (autoclave, 230 C, 48 h; cooling to 80 C at a rate of 0.1 C/min for (I) or quenching to 25 C). Crystals of NaLaSiO 4 (III) and NaYbSiO 4 (IV) are grown from La 2 O 3 (Yb 2 O 3 ), Na 2 CO 3 , and SiO 2 using a NaF/NaCl eutectic flux (Ag crucible, 900 C, 48 h). Compounds (I) to (II) crystallize in the orthorhombic space group Pca2 1 (Z = 8, single crystal XRD) while the structure of (III) is refined in the orthorhombic space group Pca2 1 (Z = 4) and (IV) in the orthorhombic space group Pnma (Z =4 [CuCl 4 ] crystallizes in the orthorhombic space group P2 1 2 1 2 1 with Z = 8 (single crystal XRD). Its asymmetric unit consists of four unique Et 2 cations and three unique anions. Two of the three Cu atoms adopt a d...

show abstract

A₅RE₄X[TO₄]₄crystal growth and photoluminescence. Fluoride flux synthesis of sodium and potassium rare earth silicate oxyfluorides

Cited by 24 publications

References 29 publications

Observation of the Same New Sheet Topology in Both the Layered Uranyl Oxide-Phosphate Cs11[(UO2)12(PO4)3O13] and the Layered Uranyl Oxyfluoride-Phosphate Rb11[(UO2)12(PO4)3O12F2] Prepared by Flux Crystal Growth

Observation of the Same New Sheet Topology in Both the Layered Uranyl Oxide-Phosphate Cs11[(UO2)12(PO4)3O13] and the Layered Uranyl Oxyfluoride-Phosphate Rb11[(UO2)12(PO4)3O12F2] Prepared by Flux Crystal Growth

A5RE4X[TO4]4 crystal growth: Fluoride flux synthesis of Na5Ln4F[GeO4]4 (Ln=Pr, Nd), the first quaternary germanate oxyfluorides

Influence of rare earth cation size on the crystal structure in rare earth silicates, Na2RESiO4(OH) (RE = Sc, Yb) and NaRESiO4 (RE = La, Yb)

Contact Info

Product

Resources

About