Structural study by Raman spectroscopy and 77Se NMR of GeSe4 and 80GeSe2–20Ga2Se3 glasses synthesized by mechanical milling

Study of the Ge20Te80-xSex glassy structures by combining solid state NMR, vibrational spectroscopies and DFT modelling

“…Either the work focused on a single composition of the Ge-Te-Se ternary system, or on a selenium or tellurium rich part of the system along the pseudo-binary line GeSe 4 -GeTe 4 . [15][16][17][18][19]21,26] However, different assignments of vibration bands have been reported showing the difficulties of interpretations. To interpret these results, the methodology used combine experimental acquisitions (Raman and IR) and DFT calculations on selected clusters to help in the assignment of the vibrational modes observed.…”

“…The echo delay between consecutive 180° pulses was set to 700 µs to allow for the recording of the entire full echo signal. Each Free Induction Decay (FID) signal was stored in a 2D buffer and FT was performed in a 2D mode as described elsewhere [21]. The recovery delay was set to 0.5 s for full relaxation, and Double Frequency Sweep (DFS) was used to enhance the intensity of the central transition signal [22].…”

“…Binary glasses Ge 20 According to the literature, these modes are assigned respectively to the symmetrical stretching of the GeSe 4 tetrahedra, the symmetrical stretching of the GeSe 4 edge-sharing tetrahedra, and finally, the stretching of the Se-Se homopolar bond into chains of variable length. [8,21] In the infrared spectrum, two broad peaks are apparent at 255 and 320 cm -1 ,mainly due to the observation of asymmetrical stretching modes of the GeSe 4 tetrahedra. presented in the Table 1.…”

Femtosecond Laser Deposition of Germanium Selenide onto Silicon Platform at Different Substrate Temperatures

“…Furthermore, the XRD pattern of the bulk GeSe4 target glass in Figure5areveals four distinct wide-stretched amorphous halo structures pinpointed at 2θ = 13, 17, 28, and 51° without any sharp peaks, which are fitted with multiple Gaussian functions. These wide-stretched bands correspond to amorphous phases of GeSe, GeSe2, and GeSe4[21,[43][44][45][46]…”

“…The XRD patterns obtained from the silicon substrate in Figure5aexhibit a strong diffraction peak centred at 2θ = 56.07 and indexed as (311). It corresponds to Bragg's reflection of cubic silicon[40][41][42][43][44][45][46][47][48][49] with the International Centre for Diffraction Data (ICDD) reference pattern No. 00-005-0565.…”