Theoretical study of the polymer molecules (TeO2)n as model systems for the local structure in TeO2 glass

Nonlinear optical properties of TeO2crystalline phases from first principles

“…To the best of our knowledge, the only χ (3) available data for tellurium oxides has been measured on the corresponding glass. 1 However, Raman spectroscopy measurements 8 have shown that the structure of γ -TeO 2 is close to the structure of this glass, so it is tempting to think that the order of magnitude of the third-order susceptibility should be the same in both the glass and the crystalline γ -TeO 2 phase.…”

“…This conclusion was extrapolated, by extension, to the case of TeO 2 -based glasses. However, another series of theoretical studies, [7][8][9][10] also carried out in the framework of DFT with hybrid functionals on (XO 2 ) n (X = Si or Te) polymer clusters of different shapes (chains, rings, and cage geometries) and sizes (monitored by the number n of XO 2 units) suggested another origin for the unusually high values of the NLO susceptibilities, highlighting the relevance of the structural features themselves, in particular, how the structural blocks (i.e., TeO 2 units) are linked together. Only one type of such molecules, the linear chains, seems to be capable of realistically reproducing the high hypersusceptibility values for the tellurium oxides.…”

Structural analysis of Cd–Te–O films prepared by RF reactive sputtering

“…This band is related with a certain degree of medium order that appears upon crystallization of the system with the substrate temperature [18]. The A and B bands could be related with the motion of the heavy elements (Te and Cd) in the structure [19,20] and B also with the v 21 TeO 3 torsion in the Te 2 O 6À 7 structure [13]. The C band is related with the m 4 d scissors mode of the (TeO 2 ) eq , with the m 19 TeO 3 torsion and with the m 20 TeO 3 rock vibrations in the Te 2 O 6À 7 structure [13,20].…”

“…The A and B bands could be related with the motion of the heavy elements (Te and Cd) in the structure [19,20] and B also with the v 21 TeO 3 torsion in the Te 2 O 6À 7 structure [13]. The C band is related with the m 4 d scissors mode of the (TeO 2 ) eq , with the m 19 TeO 3 torsion and with the m 20 TeO 3 rock vibrations in the Te 2 O 6À 7 structure [13,20]. The Te 2 O 6À 7 structure consists of a TeO 4 tbp bind to a TeO 3 through a Te-O-Te bridge [13].…”

High nonlinear optical properties in TeO2-based glasses: A modifier’s influence study from the localized hyperpolarizability approach

“…The first step of such a study has been to establish the structural unit of the tellurium oxide based glasses network. Then, several ab initio calculations on the structural properties of TeO 2 -based glasses [2][3][4][5][6][7][8] were conducted, complemented by hyperpolarizability calculations in a second step [9][10][11]. If the question of the best structural unit for calculation is still under discussion, it now appears that the localized molecular orbital method is the most efficient tool for attacking this problem.…”