Solid state 77Se NMR investigations on arsenic-selenium glasses and crystals

Bureau, Bruno; Troles, Johann; Lefloch, M.; Smektala, F.; Silly, Gilles; Lucas, Jacques

doi:10.1016/s1293-2558(02)00102-4

Cited by 71 publications

(79 citation statements)

References 21 publications

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“…In the first approach of the RMC modelling we consider only the possible heteropolar bonds, since homopolar bonds are probably absent. We have applied connectivity constraints for As atoms to be surrounded by three Se neighbours, and for Se atoms to be surrounded by two Se neighbours, as reported in many papers [5,6,[9][10][11][12][13][14][15].…”

Section: Resultsmentioning

confidence: 99%

Study of As₂Se₃and As₂Se₂Te glass structure by neutron- and X-ray diffraction methods

Fábian

Sváb

Pamukchieva

et al. 2010

J. Phys.: Conf. Ser.

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Study of As 2 Se 3 and As 2 Se 2 Te glass structure by neutron-and X-ray diffraction methods From the analysis of the partial atomic correlation functions and structure factors the first and second neighbour distances, coordination numbers and bond-angle distributions were calculated. It is established that substitution of Se by Te does not change the basic glassy network structure. For the As-Se bonding is revealed that the first neighbour distance is at 2.42 Å, the average coordination numbers are CN AsSe =2.60.1 and CN SeAs =1.80.1 atoms and the three-atom-bond angle for , configurations is 95, the same value within limit of error, as obtained from RMC calculations.

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Section: Resultsmentioning

confidence: 99%

Study of As₂Se₃and As₂Se₂Te glass structure by neutron- and X-ray diffraction methods

Fábian

Sváb

Pamukchieva

et al. 2010

J. Phys.: Conf. Ser.

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“…The slight increase of Se-SeSe (∼860 ppm) and As-Se-As (∼380 ppm) and decrease of Se-Se-As (∼580 ppm) sites in the structure of aged ChGs can be found by appropriate fitting of 77 Se NMR spectra (figure 3) too. The lines are identified from NMR data obtained earlier for vitreous As 10 Se 90 , As 23 Se 77 and As 40 Se 60 (figure 3) rich in Se-Se-Se, Se-Se-As and As-Se-As structural fragments, respectively [11,12]. So, although the observed changes are weak (in the case of NMR they only slightly exceed the noise level), both Raman and NMR methods support the idea that two As-Se-Se-As structural units transform into As-SeAs and As-Se-Se-Se-As fragments during prolonged natural storage.…”

Section: Resultsmentioning

confidence: 87%

“…The As core level was fitted by only one As 3d doublet with the intensity of the main component at ∼42.2 eV for both aged and rejuvenated samples (figure 5), which was assigned to the Se-As<(Se) 2 regular environment. The results in table 1 show that the initial ratio of (Se-Se-Se):(Se-Se-As):(As-Se-As) structural fragments for rejuvenated samples is 3%:69%:28%, which is quite close to the values (S 0 in table 1) theoretically predicted by the 'chain crossing model' for this composition: 0%:72%:28% [11,12]. After 20 years of natural storage the proportion deviates much more from this model, becoming 6%:62%:32% (table 1).…”

Section: Resultsmentioning

confidence: 99%

“…Specifically, the As 30 Se 70 composition is selected since its structure is underconstrained and would consist only of As-Se-As and As-Se-Se-As structural fragments according to the 'chain crossing model' [11,12]. Sometimes, this ChG is considered to be within the so-called 'reversibility window', where no ageing effects should occur [13].…”

Section: Introductionmentioning

confidence: 99%

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Long-term physical ageing in As–Se glasses with short chalcogen chains

Golovchak

Shpotyuk

Kozdraś

et al. 2008

J. Phys.: Condens. Matter

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Long-term physical ageing of chalcogenide glasses, which occurs over tens of years, is much less understood than the short-term ageing. With Se-rich underconstrained As 30 Se 70 glass as a model composition (consisting of Se n chains with n 3 on average), a microscopic model is developed for this phenomenon by combining information from differential scanning calorimetry, extended x-ray absorption fine structure, Raman, and 77 Se solid state nuclear magnetic resonance spectroscopies. The accompanying changes in the electronic structure of these glasses are investigated by x-ray photoelectron spectroscopy. The data suggest ageing from cooperative relaxation, presumably involving bond switching or reconfiguration of As-Se-Se-As fragments.

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“…According to B. Bureau [16][17] and for a better understanding of the NMR spectra, lines corresponding to the three expected types of Se coordination, Se-Se-Se, Se-Se-As at and As-Se -As, were added respectively at 820ppm, 550 ppm, 360 ppm. In order to understand the incorporation effect of Te, the As 30 Se 70 composition has been selected as it corresponds to theTe 20 As 30 Se 50 with a substitution of 20 % of tellurium by selenium.…”

Section: Structural Studymentioning

confidence: 99%

Te-As-Se glass destabilization using high energy milling

Calvez

Lavanant

Anna

et al. 2018

Journal of Non-Crystalline Solids

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The Te 20 As 30 Se 50 (TAS) glass has been studied under the extreme conditions of high energy milling. Starting from the raw materials, an amorphization process occurs progressively reaching an unstable intermediate state and the final stable state then. Despite its high resistance against crystallization when made using silica tubes, an intermediate state is reached when mechanically alloyed into powder. The evolution of the glass structure has been investigated using Raman spectroscopy and MAS NMR of 77 Se according to the milling time. Optimized parameters and conditions to compact milled powders by Spark Plasma Sintering show the possibility to design infrared windows transparent from 2 to 20µm. A correlation to the thermo-mechanical properties of densified powder using hot pressing has been made.

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Solid state 77Se NMR investigations on arsenic-selenium glasses and crystals

Cited by 71 publications

References 21 publications

Study of As₂Se₃and As₂Se₂Te glass structure by neutron- and X-ray diffraction methods

Study of As₂Se₃and As₂Se₂Te glass structure by neutron- and X-ray diffraction methods

Long-term physical ageing in As–Se glasses with short chalcogen chains

Te-As-Se glass destabilization using high energy milling

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Solid state 77Se NMR investigations on arsenic-selenium glasses and crystals

Cited by 71 publications

References 21 publications

Study of As2Se3and As2Se2Te glass structure by neutron- and X-ray diffraction methods

Study of As2Se3and As2Se2Te glass structure by neutron- and X-ray diffraction methods

Long-term physical ageing in As–Se glasses with short chalcogen chains

Te-As-Se glass destabilization using high energy milling

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Study of As₂Se₃and As₂Se₂Te glass structure by neutron- and X-ray diffraction methods

Study of As₂Se₃and As₂Se₂Te glass structure by neutron- and X-ray diffraction methods