Raman spectroscopic study of some lead phosphate glasses with tungsten ions

Cozar, O.; Măgdaş, Dana Alina; Nasdala, Lutz; Ardelean, I.; Damian, Grigore

doi:10.1016/j.jnoncrysol.2006.03.066

Cited by 65 publications

(34 citation statements)

References 30 publications

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“…The symmetric stretching vibrations of υ s PO 4 are assigned at 980 cm −1 in the case of some lead phosphate glasses with tungsten ions. [37] In the present study, the symmetric stretching vibrations of PO 4 are observed at 888 cm −1 (IR), at 895 cm −1 (Raman) and at 903 cm −1 theoretically.…”

Section: Ir and Raman Spectrasupporting

confidence: 57%

Vibrational spectroscopic studies and ab initio calculations of phenyl phosphate disodium salt

Anto¹,

Anto²,

Varghese³

et al. 2009

J Raman Spectroscopy

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The Fourier-transform infrared and Fourier-tranform Raman spectra of phenyl phosphate disodium salt were recorded and analyzed. The surface-enhanced Raman scattering (SERS) spectrum was recorded in a silver colloid. The vibrational wavenumbers of the compound were computed using the Hartree-Fock/6-31G * basis and compared with the experimental values. The molecule is adsorbed on the silver surface with the benzene ring in a tilted orientation. The presence of the phenyl ring and the phosphate group vibrations in the SERS spectrum reveal the interactions between the phenyl ring and the phosphate group with the silver surface. The first hyperpolarizability is calculated, and the calculated molecular geometry is compared with those of similar reported structures.

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Section: Ir and Raman Spectrasupporting

confidence: 57%

Vibrational spectroscopic studies and ab initio calculations of phenyl phosphate disodium salt

Anto¹,

Anto²,

Varghese³

et al. 2009

J Raman Spectroscopy

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“…In this region, MoO 3 enters the glass network by breaking up the P-O-P linkages and forming P-O-Mo bonds. Accordingly, the P=O bond will be converted into bridging oxygen and the phosphate bonds will be shortened (Higazy, 1985;Cozar et al, 2006). The overlapping of the absorption bands in this region confirmed the formation of shorter bonds, and the value of O/P larger than 3 confirmed the rupture of P=O bonds.…”

Section: Structural Analysismentioning

confidence: 81%

Multimodal Ultrasonic Imaging for Breast Cancer Detection

Camacho

Medina

Cruza

et al. 2012

Archives of Acoustics

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Ultrasound is used for breast cancer detection as a technique complementary to mammography, the standard screening method. Current practice is based on reflectivity images obtained with conventional instruments by an operator who positions the ultrasonic transducer by hand over the patient's body. It is a non-ionizing radiation, pain-free and not expensive technique that provides a higher contrast than mammography to discriminate among fluid-filled cysts and solid masses, especially for dense breast tissue. However, results are quite dependent on the operator's skills, images are difficult to reproduce, and state-of-the-art instruments have a limited resolution and contrast to show micro-calcifications and to discriminate between lesions and the surrounding tissue. In spite of their advantages, these factors have precluded the use of ultrasound for screening.This work approaches the ultrasound-based early detection of breast cancer with a different concept. A ring array with many elements to cover 360• around a hanging breast allows obtaining repeatable and operator-independent coronal slice images. Such an arrangement is well suited for multi-modal imaging that includes reflectivity, compounded, tomography, and phase coherence images for increased specificity in breast cancer detection. Preliminary work carried out with a mechanical emulation of the ring array and a standard breast phantom shows a high resolution and contrast, with an artifact-free capability provided by phase coherence processing.

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“…Numerous investigators [22][23][24] have undertaken experimental and theoretical research on phosphate glasses. It was established that the network of the vitreous P 2 O 5 is formed from PO 4 tetrahedral, which are connected through P-O-P linkages forming a polymeric structure.…”

Section: Ft-ir Spectroscopymentioning

confidence: 99%

Electrical and physicochemical properties of some Ag2O-containing lithia iron silica phosphate glasses

Ibrahim

Darwish

Gomaa

2011

J Mater Sci: Mater Electron

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The present paper reports the influence of Ag 2 O addition at the expense of Li 2 O on the local structure of xAg 2 OÁ(30 -x)Li 2 OÁ10Fe 2 O 3 Á10SiO 2 Á50P 2 O 5 glass matrix (with x = 0, 0.5, 1, 1.5 and 2 mol %). The phosphate structural units of the network former are assessed from Fourier transform infrared (FT-IR) spectroscopy. The addition of Ag 2 O to the glass network matrix B1 mol % leads to the occurrence of a depolymerization process of the phosphate structure and consequently, to the appearance of a distortion of the PO 4 tetrahedra. When the content of Ag 2 O is increased from 1.5 up to 2 mol %, a remarkable polymerization process has been observed. The density, molar volume, microhardness and chemical durability have been investigated in order to study the effect of Ag 2 O/Li 2 O replacements on the physicochemical properties the studied glasses. The AC electrical properties are affected to a great extent with composition. These results are related to the internal structure of the glass samples. The conductivity, dielectric constant and dielectric loss of the studied glasses were studied using the frequency response in the interval 100 Hz-100 kHz and the effect of compositional changes on the measured properties was investigated. Measurements showed that the electrical responses of glass samples were different and complex for interpretation. The increase of Ag 2 O addition at the expense of Li 2 O contents (from 0 to 1 mol %) led to increase the conductivity, dielectric constant and dielectric losses of samples. The addition of more Ag 2 O at the expense of Li 2 O (from 1.5 to 2 mol %), resulting into decreasing the conductivity, the dielectric constant and dielectric losses of the studied glasses. The experimental data of the glass samples were argued to the internal structure of the glasses and the nature and role-played by weakening or increasing the rigidity of the structure of the sample. It could be concluded, therefore, that the AC electrical properties of the samples were influenced by the distribution of its constituents, connectivity, and number of free charges.

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Raman spectroscopic study of some lead phosphate glasses with tungsten ions

Cited by 65 publications

References 30 publications

Vibrational spectroscopic studies and ab initio calculations of phenyl phosphate disodium salt

Vibrational spectroscopic studies and ab initio calculations of phenyl phosphate disodium salt

Multimodal Ultrasonic Imaging for Breast Cancer Detection

Electrical and physicochemical properties of some Ag2O-containing lithia iron silica phosphate glasses

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