125Te NMR Study of MO-TeO2(M=Mg, Zn, Sr, Ba and Pb) Glasses.

Features of electronic polarizability and approach to unique properties in tellurite glasses

“…Himei et al also measured X‐ray photoelectron spectra for alkali tellurite glasses and proposed that the peak shift of O1s and Te3d toward smaller binding energies is correlated with the increase in Lewis basicity of oxide ions in the glasses. Sakida et al examined the structure of binary tellurite glasses with different compositions by means of 125 Te static and magic‐angle spinning (MAS) NMR spectroscopies and estimated the fraction of TeO 4 tbp unit without NBO atom (), TeO 4 tbp unit with an NBO atom (), and TeO 3 tp unit with two NBO atoms ().…”

“…Based on the concept of group optical basicity proposed by Duffy and Ingram and the comprehensive data on the structure of tellurite glasses reported by Sakida et al, Dimitrov and Komatsu proposed the group optical basicities λ in tellurite glasses, that is, λ TeO4 ° = 0.99, λ TeO4 − = 1.23, and λ TeO3 − = 0.82. Ab initio quantum chemical calculations reported by Fargin et al and Suehara et al indicate that the polarizability of the TeO 3 unit is substantially less that of the TeO 4 unit, supporting the order of .…”

“…El‐Mallawany also confirmed the high molar refraction of some alkaline and alkaline‐earth binary tellurite glasses. The structure of tellurite glasses is also of interest, because tellurium (Te 4+ ) coordination polyhedron changes from TeO 4 trigonal bipyramids (tbps) to TeO 3 trigonal pyramids (tps) depending on the addition of other oxides such as Na 2 O and ZnO …”

Preparation and Characterization of BaO–TeO2 Thin Films Obtained from Tellurium(VI) Alkoxide by a Sol–Gel Method

“…Therefore, the samples prepared by the sol‐gel method contain TeO 6 units. In contrast, this peak couldn't be observed in spectra of a glass prepared by the melt‐quench method, 17 which contain the TeO 3 and TeO 4 units.…”

Mixed network former effects in tellurite glass systems: Structure/property correlations in the system (Na2O)1/3[(2TeO2)x(B2O3)1−x]2/3

“…Large amounts of four-coordinate boron were also detected in zinc borotellurite glasses [17]. Despite considerable experimental effort on different tellurite glasses [18][19][20][21][22] and crystalline model compounds [23] the interpretation of 125 Te NMR chemical shift data in terms of these structures in these glasses is still rather difficult. Wide distributions of isotropic and anisotropic chemical shifts and long spin-lattice relaxation times generally result in rather noisy MAS-NMR spectra with insufficient peak resolution.…”