Structure and nonlinear optical properties of sodium–niobium phosphate glasses

Flambard, Alexandrine; Videau, J.J.; Delevoye, Laurent; Cardinal, Thierry; Labrugère, Christine; Rivero, Clara; Couzi, M.; Montagne, Lionel

doi:10.1016/j.jnoncrysol.2008.03.017

Cited by 81 publications

(73 citation statements)

References 31 publications

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“…These samples have very low GeO 2 molar contents and thus, the main band at 800 cm À1 can be only assigned to vibrations of [NbO 6 ]. This band has been previously observed in glasses with large Nb 2 O 5 molar contents (> 20 mol%), [8][9][10]27 and assigned to Nb-O vibrations in [NbO 6 ] chains. The band shows shoulders at low (600-750 cm À1 ) and high (> 800 cm À1 ) frequencies, which are assigned to slightly and highly distorted [NbO 6 ], respectively.…”

Section: Methodssupporting

confidence: 69%

“…The band at 500-650 cm À1 is related to a three-dimensional network formed by slightly distorted [NbO 6 ] octahedra, whereas the peak at 880 cm À1 is assigned to vibrations of isolated [NbO 6 ] octahedra with NBO. [8][9][10][24][25][26] Finally, the sharp peak at 720 cm À1 is also associated to Nb-O vibrations in [NbO 6 ] octahedra. 30 Raman spectra of ternary bulk samples present a combination of the vibrational modes observed in the binary samples.…”

Section: Methodsmentioning

confidence: 94%

“…The coordination of Nb 5þ in oxide crystals is typically octahedral and rarely tetrahedral. 29 In the case of glasses most works assign the bands observed in Raman spectra to [NbO 6 ] octahedra, [8][9][10][24][25][26] although the existence of [NbO 4 ] has been proposed in the case of niobium germanate glasses. 28,30 Still, Nb-O bond lengths in [NbO 6 ] (2.0 Å ) and [NbO 4 ] (1.9 Å ) are so close that is extremely difficult to neatly assign Raman bands to modes associated to any of these units.…”

Section: Methodsmentioning

confidence: 99%

“…In this context, glasses containing Nb 2 O 5 are of particular interest due to the close relationship between the nonlinear optical response and the Nb 2 O 5 content in the glass. [8][9][10][11] This behavior has been related to the formation of three dimensional arrangements of [NbO 6 ] octahedra, which enhance the hyperpolarizability of the system. However, the bulk glass formation region may be limited to Nb 2 O 5 contents below %50 mol% as it has been observed in the case of lead niobium germanate (NPG) glasses.…”

Section: Introductionmentioning

confidence: 99%

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Structural origin of the nonlinear optical properties of lead niobium germanate film glasses

Muñoz-Martín¹,

Cruz²,

Fernández-Navarro³

et al. 2011

Journal of Applied Physics

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Linear and nonlinear optical susceptibilities and hyperpolarizability of borate LiNaB4O7 single crystals: Theory and experiment J. Appl. Phys. 112, 053526 (2012) Effect of Lorentz local field for optical second order nonlinear susceptibility in ZnO nanorod J. Appl. Phys. 111, 103112 (2012) Size dependent optical properties of the CdSe-CdS core-shell quantum dots in the strong confinement regime J. Appl. Phys. 111, 074312 (2012) Methyl groups at dielectric and metal surfaces studied by sum-frequency generation in co-and counterpropagating configurations J. Chem. Phys. 135, 044704 (2011) The third-order nonlinear optical coefficients of Si, Ge, and Si1−xGex in the midwave and longwave infrared J. Appl. Phys. 110, 011301 (2011) Additional information on J. Appl. Phys. The structural origin of the nonlinear optical susceptibility (/v (3) /) of lead-niobium-germanate film glasses with large Nb 2 O 5 contents has been investigated. /v (3) / shows a strong enhancement with the Nb content in the films with /v (3) / values close to 2 Â 10 À11 esu at 800 nm for a Nb content as high as 0.71. Boling-Glass-Owyoung and Lines' semiempirical models predict accurately the values of /v (3) / for transparent bulk glasses but not for film glasses. This discrepancy is related to the remarkable structural differences between them. Raman spectroscopy suggests the formation of a three-dimensional (3D) structure of [NbO 6 ] octahedra in the case of film glasses having large Nb contents, while X-ray photoelectron spectroscopy shows that a significant fraction of these units contain Nb 4þ ions. The combination of a 3D structure of [NbO 6 ] with the presence of Nb 4þ polarons and their migration through electron intervalence transfer is proposed as the origin of the observed enhancement of /v (3) / in the film glasses.

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Section: Methodssupporting

confidence: 69%

Section: Methodsmentioning

confidence: 94%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Structural origin of the nonlinear optical properties of lead niobium germanate film glasses

Muñoz-Martín¹,

Cruz²,

Fernández-Navarro³

et al. 2011

Journal of Applied Physics

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“…The ratio of bridging oxygen to non-bridging oxygen in the polyphosphate glass was calculated by dividing the intensity of BO and NBO peaks obtained from XPS analysis. This approach has been extensively used in literature [42][43][44][45][46][47][48][49][50]. Also the binding energy difference between the Zn3s and P2p peaks in the XPS spectra was used to give complementary information.…”

Section: Chemistry Of the Tribofilmmentioning

confidence: 99%

A new insight into the interfacial mechanisms of the tribofilm formed by zinc dialkyl dithiophosphate

Parsaeian

Ghanbarzadeh

Eijk

et al. 2017

Applied Surface Science

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Understanding the true interfacial mechanisms involved in the growth of tribofilms generated by Zinc Dialkyl Dithiophosphate (ZDDP) is important because it is the most widely used antiwear additive and there is legislative pressure to find efficient environmentally-friendly replacements. The main focus of this study is to investigate the durability of the ZDDP tribofilm and correlate it to the chemical and physical properties of the glassy polyphosphates.A novel experimental method has been developed to study the effect of lubricant temperature and contact load on tribofilm growth and durability. Results show that physical parameters such as temperature and pressure significantly influence the tribofilm durability. XPS analyses were carried out before suspending the test and after changing the oil to assess the difference in chemical structure of the tribofilm before and after stopping the test. The chemical analyses suggest that there are different chemical properties across the thickness of the tribofilm and these determine the durability characteristics.

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