scholarly journals Формирование нанокристаллов германия в пленках GeO[SiO-=SUB=-2-=/SUB=-] и GeO[SiO]

2021 ◽  
Vol 55 (6) ◽  
pp. 507
Author(s):  
Zhang Fan ◽  
С.Г. Черкова ◽  
В.А. Володин
Keyword(s):  
Raman Spectroscopy ◽  
Fourier Transform ◽  
Annealing Temperature ◽  
High Vacuum ◽  
Spectroscopy Technique ◽  
Spectroscopy Analysis ◽  
Si Nanocrystals ◽  
Fused Quartz ◽  
Germanium Nanocrystals ◽  
Quartz Substrates

Films of nonstoichiometric germanosilicate glasses GeO0.5[SiO2]0.5 and GeO0.5[SiO]0.5 were obtained by co-evaporation of GeO2 and SiO2 or GeO2 and SiO powders, respectively, and by deposition on cold Si (100) and fused quartz substrates in a high vacuum. Then the films were annealed at temperatures up to 900 oC. The presence and phase composition of germanium nanoclusters in the films was investigated using Raman spectroscopy technique. The transformation after annealing of the GeSixOy matrix surrounding the nanoclusters was investigated using Fourier transform infrared spectroscopy. Analysis of the Raman spectra showed that annealing at a temperature of 800 oC led to the formation of germanium nanocrystals (NC-Ge), but the content of the amorphous germanium phase remains up to half of the volume. Annealing at a temperature of 900 oC led to almost complete crystallization of amorphous nanoclusters in all films. The sizes of the NC-Ge depended on the annealing temperature, the composition of the films, and on the substrate; in this case, the formation of Ge-Si nanocrystals was not observed.

Structural and Optical Properties of the Thermally Stable Amorphous Si1−xBx Alloy.

1993 ◽  
Vol 297 ◽  
Author(s):  
Johan R. A. Carlsson ◽  
X.H. Li ◽  
S.F. Gong ◽  
H.T.G. Hentzell
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Annealing Temperature ◽  
High Vacuum ◽  
Vacuum System ◽  
Structural And Optical Properties ◽  
Microstructural Alterations ◽  
Amorphous Si ◽  
Means Of Transmission ◽  
Quartz Substrates

Thin amorphous Si1−xBx films were co-evaporated onto pre-oxidized (100) Si wafers and quartz substrates, by using a high vacuum system with 2 electron guns. Films were deposited in a composition range from x=0 to x=0.5. In order to study how the structural and optical properties depended on concentration and annealing temperature, heat treatments were carried out at temperatures from 400 up to 1000°C. The films were characterized by means of transmission electron microscopy (TEM), Auger electron spectroscopy (AES), and light absorption spectrophotometry. It is shown that the amorphous Si1−xBx alloy is stable up to 1000°C at certain compositions and that the optical band gap of the alloy increases gradually with increasing annealing temperature up to 700 - 900°C, and then increases rapidly when annealed at a higher temperature by about 0.5 eV. These changes can be associated with microstructural alterations. The relationship between the microstructure and the band gap of the films is discussed.

IMPACTS OF ANNEAL TEMPERATURE ON THE STRUCTURAL, MAGNETIC AND OPTICAL PROPERTIES OF THE Fe:LaSrFeO4 COMPOSITE FILM

2016 ◽  
Vol 23 (06) ◽  
pp. 1650060
Author(s):  
J. SHI ◽  
Y. L. JIA ◽  
X. H. LI ◽  
X. H. DAI ◽  
J. X. GUO ◽  
...  
Keyword(s):  
Room Temperature ◽  
Annealing Temperature ◽  
High Vacuum ◽  
Composite Films ◽  
Annealed Sample ◽  
Absorption Properties ◽  
Oxygen Loss ◽  
Quartz Substrates ◽  
Anneal Temperature ◽  
Intrinsic Strain

We prepared the pulsed laser deposited Fe:LaSrFeO4 (LSFO) composite films on quartz substrates by decomposing the La[Formula: see text]Sr[Formula: see text]FeO3 target at room temperature in a high vacuum. Impacts of anneal temperature on the structural and physical properties have been investigated, and the systematic changes were found in structural, magnetic and optical absorption properties upon annealing. The LSFO (110) spacing decreases with the increase of annealing temperature, which can be attributed to the release of intrinsic strain; and there is an increase in spacing for the 750[Formula: see text]C annealed sample, which is ascribed to the oxygen loss in LSFO films.

An amorphous-to-crystalline phase transition within thin silicon films grown through ultra-high-vacuum evaporation on fused quartz substrates

MRS Advances ◽  
2016 ◽  
Vol 1 (48) ◽  
pp. 3257-3262
Author(s):  
Farida Orapunt ◽  
Li-Lin Tay ◽  
David J. Lockwood ◽  
Jean-Marc Baribeau ◽  
Joanne C. Zwinkels ◽  
...  
Keyword(s):  
Phase Transition ◽  
Volume Fraction ◽  
High Vacuum ◽  
Optical Quality ◽  
Vacuum Evaporation ◽  
Silicon Films ◽  
Ultra High Vacuum ◽  
Fused Quartz ◽  
Thin Silicon ◽  
Quartz Substrates

ABSTRACTA number of thin silicon films are prepared through ultra-high-vacuum evaporation on optical quality fused quartz substrates with different growth temperatures. Through an analysis of grazing incidence X-ray diffraction results, a phase transition, from amorphous-to-crystalline, is found corresponding to increases in the growth temperature. The corresponding Raman spectra are also observed to change their form as the films go through this phase transition. Using a Raman peak decomposition process, this phase transition is then quantitatively characterized through the determination of the amount of intermediate-range order and the crystalline volume fraction for the various growth temperatures considered in this analysis. The possible device consequences of these results are then commented upon.

scholarly journals Use of WetSEM® capsules for convenient multimodal scanning electron microscopy, energy dispersive X-ray analysis, and micro Raman spectroscopy characterisation of technetium oxides

2021 ◽  
Author(s):  
D. J. Bailey ◽  
M. C. Stennett ◽  
J. Heo ◽  
N. C. Hyatt
Keyword(s):  
Raman Spectroscopy ◽  
Low Cost ◽  
Powder Materials ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Hazard And Risk ◽  
Sem Imaging ◽  
General User ◽  
532 Nm

AbstractSEM–EDX and Raman spectroscopy analysis of radioactive compounds is often restricted to dedicated instrumentation, within radiological working areas, to manage the hazard and risk of contamination. Here, we demonstrate application of WetSEM® capsules for containment of technetium powder materials, enabling routine multimodal characterisation with general user instrumentation, outside of a controlled radiological working area. The electron transparent membrane of WetSEM® capsules enables SEM imaging of submicron non-conducting technetium powders and acquisition of Tc Lα X-ray emission, using a low cost desktop SEM–EDX system, as well as acquisition of good quality μ-Raman spectra using a 532 nm laser.

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