An NMR study of silicon coordination in Y–Si–Al–O–N glasses

Aujla, R. S.; Leng-Ward, G.; Lewis, M. H.; Seymour, E F W; Styles, G.A.; West, Gerhard

doi:10.1080/13642818608239002

Cited by 49 publications

(35 citation statements)

References 8 publications

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“…The structure of M-Si-Al-O(-N) is not extensively known, particularly in terms of medium range order, but numerous studies give information on the first coordination sphere of different cations [17][18][19][20][21][22][23][24][25][26][27][28][29][30]. For example Si is a tetrahedrally coordinated structural network former, forming rather covalent bonds with oxygen or nitrogen.…”

Section: Introductionmentioning

confidence: 99%

Irradiation-induced changes in the local environment of Si and Al in LnSiAlON glasses as probed by 27Al and 29Si NMR

Dauce¹,

Floch²,

Sangleboeuf³

et al. 2007

Journal of Non-Crystalline Solids

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Section: Introductionmentioning

confidence: 99%

Irradiation-induced changes in the local environment of Si and Al in LnSiAlON glasses as probed by 27Al and 29Si NMR

Dauce¹,

Floch²,

Sangleboeuf³

et al. 2007

Journal of Non-Crystalline Solids

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“…Regarding the simulation results (Table 3), Q 4 units represent about 6% of the silicate tetrahedra. According [12]. Chemical shifts, FWHMs and percentages of each structural unit are summarized in Table 3.…”

Section: Structurementioning

confidence: 99%

“…In terms of structure, Si and Al are considered to be typical network formers covalently linked via oxygen or nitrogen atoms. In this covalent network, metallic modifiers create non-bridging oxygen atoms (NBO, the occurrence of nonbridging nitrogen has been more seldom reported) [12][13][14][15][16][17][18][19][20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

On the relations between ISE and structure in some RE(Mg)SiAlO(N) glasses

Dauce¹,

Keding²,

Sangleboeuf³

2008

J Mater Sci

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Six oxide and oxynitride glasses were synthesized in the Y-Mg-Si-Al-O-N, Nd-Mg-Si-Al-O-N and La-MgSi-Al-O-N systems. As already known, nitrogen introduction increases the T g , packing factor and mechanical properties of the glasses. Cationic substitution also has an influence on the glasses' behavior, particularly in terms of sensitivity to indentation load/size effect (ISE). The structure of the yttrium-containing glasses was investigated by mean of 27 Al and 29

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“…The 29Si resonance in a series of oxynitride glasses of general composition Yl.04Si1.27AI1.2706-xNx (0 ~x ~ 1.2) was investigated by Aujla et al (1986). Distinct lines from the different Si(0,N)4 tetrahedra were not resolved, but the data could be best fitted with a distribution of tetrahedral units having a shift change of 12.5 ppm for each replacement of an oxygen by a nitrogen and by assuming that each nitrogen enters the network producing 2( ± 0.2) Si-N bonds and 1 AI-N bond (see Chapter 4 for further discussion of oxynitride glass structure).…”

Section: Oxynitride Glassesmentioning

confidence: 99%

MAS NMR: a new spectroscopic technique for structure determination in glasses and ceramics

Dupree¹,

Holland²

1989

Glasses and Glass-Ceramics

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NMR has long been used to obtain structural information about glasses. Fairly recent reviews of standard wide line NMR have been given by MullerWarmuth and Eckert (1982), Bray et at. (1983) and Bray and Gravina (1985). The information given by these studies has, in the main, been concentrated on quadrupolar nuclei, for example the use of llB to determine the relative amounts of 3 and 4 fold co-ordinated boron in glasses. Other main themes have been concerned with using dipolar broadened lineshapes to test for the probability of particular local configurations.Much of the structural information potentially available from NMR experiments is masked in solids by various static anisotropic nuclear interactions which broaden the line and make the small differences in position undetectable. These include the magnetic dipolar interaction, the anisotropic chemical shift interaction and, for nuclei with spin I> 112, the quadrupolar interaction. The dipolar interaction arises from the magnetic field at one nucleus produced by neighbouring nuclei and varies as the inverse cube of the distance between nuclei. The chemical shift is caused by bonding of the atom to its surroundings so that each crystallographic site will have a particular shift with three components corresponding to the three principal axes. For a site of cubic point group the chemical shift will be isotropic, for sites of lower symmetry the shift will be anisotropic and in microcrystalline and glassy (it is the local symmetry that is important) samples lineshapes such as those shown in Fig is defined as (all + a22 + a33)/3, thus a,!:la = a33 -alb 17 are sufficient to describe the chemical shift parameters.For nuclei with spin I> 112 the interaction of the nuclear quadrupole moment (eQ) with the electric field gradient (a 2 VlaZ 2 = eq) at the nucleus will alter the nuclear energy levels depending upon the relative orientation of the electric field gradient and the applied magnetic field and to first order in the quadrupolar interaction will give the powder pattern shown in MAS NMR: a new technique for structure determinationobservable in powders, and it will be broadened and can have a complex shape dependent on the quadrupolar asymmetry parameter; examples are shown in Fig. 1.2(b) and (c).In a liquid the NMR lines are usually very narrow because all of these broadening mechanisms have, in first order, a 3 cos 2 0-1 angular dependence and this averages to zero under the rapid motion present. Recently various line narrowing techniques, such as magic angle spinning (MAS) where the sample is orientated at 54° 44' (cos 0 = 1/y3) to the magnetic field and spun rapidly (Andrew, 1981), have been developed such that in favourable crystalline materials a reduction in linewidth of more than two orders of magnitude can be achieved and the underlying structural information present in the spectrum obtained. The improvement is less marked in glasses because of the disorder but the resolution is often sufficient to give much unique structural information. corresponds to ...

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An NMR study of silicon coordination in Y–Si–Al–O–N glasses

Cited by 49 publications

References 8 publications

Irradiation-induced changes in the local environment of Si and Al in LnSiAlON glasses as probed by 27Al and 29Si NMR

Irradiation-induced changes in the local environment of Si and Al in LnSiAlON glasses as probed by 27Al and 29Si NMR

On the relations between ISE and structure in some RE(Mg)SiAlO(N) glasses

MAS NMR: a new spectroscopic technique for structure determination in glasses and ceramics

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