A comparison of the long wave optical phonons in trigonal Se and trigonal Te

Abstract

The frequencies of the long wave optical phonons in trigonal Se and Te are compared.Differences in the relative frequencies of the A, and A, modes, and in several of the elastic constants as well, are attributed to differences in the intra-and inter-chain bonding. These comparisons are made quantitative by defining reduced lattice dynamical properties in which the nearest and second nearest neighbor distances are used as scaling parameters respectively for the intra-and inter-chain properties. The comparison is extended to the optic mode frequencies of amorphous Se and Te.Die Frequenzen der langwelligen optischen Phononen in trigonalem Se und Te werden verglichen. Die Unterschiede in den relativen Frequenzen der A,-und A,-Moden und einiger elastischer Konstanten werden Unterschieden in den Bindungen innerhalb der Kette (Intra-Bindung) und den benachbarten Ketten (Inter-Bindung) zugeschrieben. Die Vergleiche werden quantitativ ausgewertet, indem die reduzierten, dynamischen Eigenschaften des Gitters definiert werden. Der Abstand nachster Nachbarn definiert die Intra-Bindungen und der niichste Abstand zwischen Atomen benachbarter Ketten definiert die InterBindungseigenschaften. Der Vergleich wird auch auf die optischen Freqnenzen von amorphem Se und Te ansgedehnt.

Anomalous Raman modes in tellurides

“…[7][8][9]11,14,23,30,40 In order to substantiate this hypothesis, we have compared the ARS in Figure 1 with the unpolarized RS (Figure 2) and polarized RS of crystalline trigonal Te for different polarizations (see Figure S3 in the SI). As regards our unpolarized and polarized RS of crystalline Te, they are similar to those reported in the literature 9,47,[53][54][55] and show three main bands around 91, 120 and 140 cm -1 corresponding to the three first-order Raman modes E 1 (TO), A1 and E 2 (TO) modes of trigonal Te. We have noted the two E modes of trigonal Te with superindexes 1 and 2 to distinguish for the low and highwavenumber modes, respectively.…”

Hydrostatic Pressure Dependence of First‐Order Raman Frequencies in Se and Te

“…Five of the six optical modes are Raman active: one is of type A, and is solely Raman active. the two doubly degenerate type E vibrations are also infrared active (for a review see [13]). We shall denote the low-frequency E-mode E' and the high frequency E-mode E".…”

Tellurium quantum dots: Preparation and optical properties

“…The AFM image of the TeQDs is shown in Figure 2 the TeQDs. 19 The shift towards higher frequencies could be related to the surface effect. As the diameter of the tellurium reduces, the surface area and surface energy would increase drastically.…”