Amorphous chalcogenides as random octahedrally bonded solids: I. Implications for the first sharp diffraction peak, photodarkening, and Boson peak

2017 ◽  
Vol 147 (11) ◽  
pp. 114505 ◽  
Author(s):  
Alexey Lukyanov ◽  
Vassiliy Lubchenko
2021 ◽  
Vol 24 (3) ◽  
pp. 312-318
Author(s):  
A.V. Stronski ◽  
◽  
T.S. Kavetskyy ◽  
L.O. Revutska ◽  
I. Kaban ◽  
...  

The parameters of the boson peak (BP) and the first sharp diffraction peak (FSDP) in (As2S3)x(GeS2)1x glasses measured using high-resolution Raman spectroscopy and high-energy synchrotron X-ray diffraction measurements are examined as a function of x. It has been found that there is no correlation between the positions of BP and FSDP. The BP position shows a nonlinear composition behavior with a maximum at about x = 0.4, whereas the FSDP position changes virtually linearly with x. The intensities of both BP and FSDP show nonlinear composition dependences with the slope changes at x = 0.4, although there is no direct proportionality. Analysis of the partial structure factors for the glasses with x = 0.2, 0.4 and 0.6 obtained in another study has shown that the cation-cation atomic pairs of Ge–Ge, Ge–As and As–As make the largest contribution to FSDP, where the Ge–Ge and Ge–As pairs are dominant.


Author(s):  
Frastica Deswardani ◽  
Helga Dwi Fahyuan ◽  
Rimawanto Gultom ◽  
Eif Sparzinanda

Telah dilakukan penelitian mengenai pengaruh konsentrasi doping karbon pada lapisan tipis TiO2 yang ditumbuhkan dengan metode spray terhadap struktur kristal dan morfologi TiO2. Hasil karakterisasi SEM menunjukkan bahwa penambahan doping karbon dapat meningkatkan ukuran butir. Lapisan TiO2 doping karbon 8% diperoleh ukuran butir terbesar adalah 1.35 μm, sedangkan ukuran tekecilnya adalah 0.45 μm. Sementara itu, untuk lapisan tipis TiO2 didoping karbon 15% memiliki ukuran butir terbesar yaitu 1.76 μm dan terkecil 0.9 μm. Hasil XRD menunjukkan seluruh puncak difraksi lapisan tipis TiO2 dengan doping karbon 8% dan 15% merupakan TiO2 anatase. Ukuran kristal lapisan TiO2 didoping karbon 8% diperoleh sebesar 638,08 Å dan untuk pendopingan 15% karbon ukuran kristal lapisan tipis TiO2 adalah 638,09 Å, hal ini menunjukkan ukuran kristal kedua sampel tidak mengalami perubahan yang signifikan.   TiO2 thin film with carbon doping has been successfully grown by spray method. The research on the effect of carbon doping on crystal structure and morfology of TiO2 has been prepared by varying carbon concentration (8% and 15% carbon). Analysis of SEM showed that the addition of carbon may increase the grain size. Thin film of TiO2 doped carbon 8% has the largest grain size 1.35 μm, while the smallest grain size is 0.45 μm. Meanwhile, for thin film TiO2 doped carbon 15% has the largest grain size 1.76 μm and smallest 0.9 μm. The XRD results showed the entire diffraction peak of thin film TiO2 doped carbon 8% and 15% were TiO2 anatase. The crystal size of thin film TiO2 doped carbon 8% was obtained at 638.08 Å and for thin film TiO2 doped carbon 15% the crystalline size of TiO2 thin film was 638.09 Å, this shows that the crystal size of both samples did not change significantly.    


Author(s):  
В. Міца ◽  
О. Фегер ◽  
С. Петрецький ◽  
Р. Голомб ◽  
В. Ткач

2021 ◽  
pp. 2000447
Author(s):  
Devilal Dahal ◽  
Hiroka Warren ◽  
Parthapratim Biswas

Author(s):  
Mariana Fatobene Ando ◽  
Sindy Fuhrmann ◽  
Zhiwen Pan ◽  
Bruno Poletto Rodrigues ◽  
Tatsuya Mori ◽  
...  

2021 ◽  
Vol 11 (15) ◽  
pp. 6733
Author(s):  
Mira Naftaly ◽  
Andrew Gregory

Z-cut single-crystal quartz and vitreous silica (silica glass or fused silica) were evaluated for use as reference materials for terahertz and microwave measurements of complex permittivity, with Z-cut quartz confirmed as being suitable. Measurements of refractive indices and absorption coefficients for o-ray and e-ray in quartz and for vitreous silica are reported at frequencies between 0.2 and 6 THz and at 36 and 144 GHz, and compared with data reported in the literature. A previously unreported broad band was seen in the extraordinary absorption of quartz. The Boson peak in silica glass absorption was examined, and for the first time, two negative relationships have been observed: between the refractive index and the Boson peak frequency, and between the Boson peak height and its frequency.


2020 ◽  
Vol 2 (2) ◽  
Author(s):  
D. L. Cortie ◽  
M. J. Cyster ◽  
T. A. Ablott ◽  
C. Richardson ◽  
J. S. Smith ◽  
...  

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