Vibrational spectra of α-Ge(HPO4)2·H2O compound

Moraes, Aline Pereira; Romano, Ricardo; Filho, A. G. Souza; Freire, Paulo; Filho, J. Mendes; Alves, Oswaldo Luiz

doi:10.1016/j.vibspec.2005.09.003

Cited by 9 publications

(2 citation statements)

References 15 publications

(21 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fig. 3, shows FT-IR spectra of α-Ge(HPO 4 ) 2 .1.84H 2 O (nGeP) in the range 4000-400 cm -1 , found to be similar to that reported for α-Ge(HPO 4 ) 2 .H 2 O [21,22]. A tentative assignment of various vibrational modes is proposed based on previous works preformed in other M(IV) phosphate compounds [1,23].the narrow bands at ~ 3550-3357 cm -1 and ~1632 cm -1 are assigned to vibrational modes of H 2 O molecules, suggest that water molecules are located at well defined crystallographic sites.…”

Section: Resultssupporting

confidence: 73%

Polystyrene/Lamellar Germanium Phosphate Nanocomposite Membranes

Shakshooki

El-Akari

El-Fituri

et al. 2013

AMR

View full text Add to dashboard Cite

Novel nanosized lamellar germanium phosphate, α-Ge (HPO4)2.1.84H2O(nGeP), with interlayer spacing (d001) = 7.71Ǻ, was prepared. Preparations of polystyrene/lamellar germanium phosphate nanocomposite membranes were carried out by mixing slurry tetrahydrofuran (THF) solution of (nGeP) , of different weight percentages (2.5, 5 and 15 wt %), with (THF) solution of 5% polystyrene (PS) in concentration at 45°C with stirring for 48 hours. The resultant mixtures were poured into flat surface containers, of desired thickness, respectively, and allowed to dry in air. The resulting fully dried composites were pealed from the glass containers. The composite membranes were transparent flexible thin films and were characterized by XRD, TGA, FT-IR, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Size particles of lamellar germanium phosphate calculated from XRD broadening method using the Scherrer,s equation, found to be 44.6 nm . TEM images of nanocomposites show that the (nGeP) in the nanometer scale, in the range 38-53 nm. The composite materials show to have mechanical and thermal stability properties superior to that of the original polymer, which a result of the enhancement of the thermal properties of PS/nGeP nanocomposites. The exchange capacities of the resultant composite membranes were investigated.

show abstract

Section: Resultssupporting

confidence: 73%

Polystyrene/Lamellar Germanium Phosphate Nanocomposite Membranes

Shakshooki

El-Akari

El-Fituri

et al. 2013

AMR

View full text Add to dashboard Cite

show abstract

“…Although the thickness was reduced (100 µm), the absorbance was below 1300 cm −1 due to the tetrahedral P-O modes, and is evidently out of scale; in the OH-stretching region, two broad bands are observed, centered at 2905 and 2415 cm −1 , respectively (Figure 8). Cooper et al (2013) [31] presented a very similar pattern for the closely related wopmayite and assigned the former component to the (P)-OH stretching mode, while the latter, following the work of Moraes et al (2006) [52] was assigned to an overtone of the P-O modes. This assignment is supported, although not conclusively, by the polarized spectra displayed in Figure 8 that show a significant reduction of the intensity of the 2905 cm −1 component with respect the 2415 cm −1 band when the electric vector (E) is ⊥ c. The intensity of the 2905 cm −1 band for both polarization directions is in agreement with the alignment of the O-H vector along a direction intermediate between the crystallographic axes [53].…”

Section: Ftir Spectroscopymentioning

confidence: 82%

Neutron and XRD Single-Crystal Diffraction Study and Vibrational Properties of Whitlockite, the Natural Counterpart of Synthetic Tricalcium Phosphate

et al. 2021

View full text Add to dashboard Cite

A crystal chemical investigation of a natural specimen of whitlockite, ideally Ca9Mg(PO4)6[PO3(OH)], from Palermo Mine (USA), was achieved by means of a combination of electron microprobe analysis (EMPA) in WDS mode, single-crystal neutron diffraction probe (NDP) and single-crystal X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. The crystal-chemical characterization resulted in the empirical formula (Ca8.682Na0.274Sr0.045)Σ9.000(Ca0.034□0.996)Σ1.000(Mg0.533Fe2+0.342Mn2+0.062Al0.046)Σ0.983(P1.006O4)6[PO3(OH0.968F0.032)Σ1.000]. Crystal-structure refinement, in the space group R3c, converged to R1 = 7.12% using 3273 unique reflections from NDP data and to R1 = 2.43% using 2687 unique reflections from XRD data. Unit cell parameters from NDP are a = 10.357(3) Å, c = 37.095(15) Å and V = 3446(2) Å3, and from XRD, the parameters are a = 10.3685(4) Å, c = 37.1444(13) Å and V = 3458.2(3) Å3. NDP results allowed a deeper definition of the hydrogen-bond system and its relation with the structural unit [PO3(OH)]. The FTIR spectrum is very similar to that of synthetic tricalcium phosphate Ca3(PO4)2 and displays minor band shifts due to slightly different P-O bond lengths and to the presence of additional elements in the structure. A comparison between whitlockite, isotypic phases from the largest merrillite group, and its synthetic counterpart Ca3(PO4)2 is provided, based on the XRD/NDP and FTIR results.

show abstract

Two Cadmium Germanophosphates [CdGe(μ₂ -O)(HPO₄ )₂ - (H₂ O)₂ ]^. H₂ O and Anhydrous Cd₇ Ge(PO₄ )₆ : Syntheses, Crystal Structures and Photoluminescence Properties

et al. 2017

View full text Add to dashboard Cite

Two cadmium germanophosphates (GePOs), namely, [CdGe(μ2‐O)(HPO4)2(H2O)2].H2O (1) and anhydrous Cd7Ge(PO4)6 (2) have been prepared by hydro/solvothermal method. Compound 1 crystallizes in a centrosymmetric (CS) space group P‐1 with a 2D layer structure, which is composed of 1D [Cd(HPO4)4(H2O)2]∞ and [Ge(μ2‐O)2(HPO4)4]∞ infinite chains. Compound 2 crystallizes in a centrosymmetric space group R‐3 with a complicated 3D network, which is built from CdO6 octahedra, GeO6 octahedra and PO4 tetrahedra. TGA results showed that the structure of anhydrous Cd7Ge(PO4)6 was stable under 800 °C. The luminescent properties of two compounds were also investigated at room temperature. The color coordinate of 2 (0.2613, 0.2649) is close to that of the balanced white‐light emission (0.333, 0.333), which indicates that compound 2 is a good blue light emitted material at room temperature under UV irradiation exaction, thus anhydrous compound 2 might be a potential candidate for blue light‐emitted material.

show abstract

Vibrational spectra of α-Ge(HPO4)2·H2O compound

Cited by 9 publications

References 15 publications

Polystyrene/Lamellar Germanium Phosphate Nanocomposite Membranes

Polystyrene/Lamellar Germanium Phosphate Nanocomposite Membranes

Neutron and XRD Single-Crystal Diffraction Study and Vibrational Properties of Whitlockite, the Natural Counterpart of Synthetic Tricalcium Phosphate

Two Cadmium Germanophosphates [CdGe(μ₂ -O)(HPO₄ )₂ - (H₂ O)₂ ]^. H₂ O and Anhydrous Cd₇ Ge(PO₄ )₆ : Syntheses, Crystal Structures and Photoluminescence Properties

Contact Info

Product

Resources

About

Vibrational spectra of α-Ge(HPO4)2·H2O compound

Cited by 9 publications

References 15 publications

Polystyrene/Lamellar Germanium Phosphate Nanocomposite Membranes

Polystyrene/Lamellar Germanium Phosphate Nanocomposite Membranes

Neutron and XRD Single-Crystal Diffraction Study and Vibrational Properties of Whitlockite, the Natural Counterpart of Synthetic Tricalcium Phosphate

Two Cadmium Germanophosphates [CdGe(μ2 -O)(HPO4 )2 - (H2 O)2 ]. H2 O and Anhydrous Cd7 Ge(PO4 )6 : Syntheses, Crystal Structures and Photoluminescence Properties

Contact Info

Product

Resources

About

Two Cadmium Germanophosphates [CdGe(μ₂ -O)(HPO₄ )₂ - (H₂ O)₂ ]^. H₂ O and Anhydrous Cd₇ Ge(PO₄ )₆ : Syntheses, Crystal Structures and Photoluminescence Properties