Temperature dependences of optical properties, chemical composition, structure, and laser damage in Ta
                    2
                    O
                    5
                    films

In order to reveal the influence of oxidization on the properties of AlF3 films, single layers of AlF3 were deposited at different substrate temperature by thermo evaporation technique with or without oxygen injected into the coating chamber. The chemical composition, total stress, optical properties and laser damage resistance of samples were characterized. Comparative study indicates the AlF3 films prepared under higher oxygen pressure have more oxides which result from hydration process in atmosphere. The presence of oxides also reduces total stress and optical absorption of the fluoride coatings.

Download Full-text

Structural/Property Relationships for Optical Materials

MRS Proceedings ◽

10.1557/proc-329-215 ◽

1993 ◽

Vol 329 ◽

Author(s):

Vivien D.

Keyword(s):

Crystal Structure ◽

Optical Properties ◽

Electronic Structure ◽

Chemical Composition ◽

Field Strength ◽

Optical Materials ◽

Site Occupancy ◽

Laser Materials ◽

Crystal Field Strength ◽

The Matrix

AbstractIn this paper the relationships between the crystal structure, chemical composition and electronic structure of laser materials, and their optical properties are discussed. A brief description is given of the different laser activators and of the influence of the matrix on laser characteristics in terms of crystal field strength, symmetry, covalency and phonon frequencies. The last part of the paper lays emphasis on the means to optimize the matrix-activator properties such as control of the oxidation state and site occupancy of the activator and influence of its concentration.

Download Full-text

Effect of plasma treatment on chemical composition, structure and sorption properties of lignocellulosic hemp fibers (Cannabis sativa L.)

Carbohydrate Polymers ◽

10.1016/j.carbpol.2020.116000 ◽

2020 ◽

Vol 236 ◽

pp. 116000 ◽

Cited By ~ 2

Author(s):

Biljana M. Pejić ◽

Ana D. Kramar ◽

Bratislav M. Obradović ◽

Milorad M. Kuraica ◽

Andrijana A. Žekić ◽

...

Keyword(s):

Chemical Composition ◽

Plasma Treatment ◽

Cannabis Sativa ◽

Sorption Properties ◽

Hemp Fibers ◽

Composition Structure ◽

Structure And Sorption Properties

Download Full-text

Optical properties and chemical composition of the atmospheric aerosol in urban Guangzhou, China

Atmospheric Environment ◽

10.1016/j.atmosenv.2008.01.030 ◽

2008 ◽

Vol 42 (25) ◽

pp. 6335-6350 ◽

Cited By ~ 215

Author(s):

Meinrat O. Andreae ◽

Otmar Schmid ◽

Hong Yang ◽

Duli Chand ◽

Jian Zhen Yu ◽

...

Keyword(s):

Optical Properties ◽

Chemical Composition ◽

Atmospheric Aerosol

Download Full-text

On the effects of thermal treatment on the composition, structure, morphology, and optical properties of hydrogenated amorphous silicon-oxycarbide

Journal of Materials Research ◽

10.1557/jmr.2009.0308 ◽

2009 ◽

Vol 24 (8) ◽

pp. 2561-2573 ◽

Cited By ~ 14

Author(s):

Spyros Gallis ◽

Vasileios Nikas ◽

Eric Eisenbraun ◽

Mengbing Huang ◽

Alain E. Kaloyeros

Keyword(s):

Optical Properties ◽

Thermal Treatment ◽

Amorphous Silicon ◽

Hydrogenated Amorphous Silicon ◽

Effective Cross Section ◽

Silicon Oxycarbide ◽

Nuclear Reaction Analysis ◽

Structure Morphology ◽

Composition Structure ◽

Hydrogenated Amorphous

The composition, structure, morphology, and optical characteristics of hydrogenated amorphous silicon-oxycarbide (a-SiCxOyHz) materials were investigated as a function of experimental processing conditions and post-deposition thermal treatment. Thermal chemical vapor deposition (TCVD) was applied to the growth of three different types of a-SiCxOyHz films, namely, SiC-like (SiC1.08O0.07H0.21), Si-C-O (SiC0.50O1.20H0.22), and SiO2-like (SiC0.20O1.70H0.24). The resulting films were subsequently annealed at temperatures ranging from 500 °C to 1100 °C for 1 h in an argon atmosphere. The composition, structure, and morphology of as-deposited and post-annealed films were characterized by Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS), Rutherford backscattering spectroscopy (RBS), nuclear-reaction analysis (NRA), and scanning electron microscopy. Corresponding optical properties were assessed by spectroscopic ultraviolet-visible ellipsometry (UV-VIS-SE). These studies led to the identification of an optimized process window for the growth of Er doped silicon oxycarbide (SiC0.5O1.0:Er) thin film with strong room-temperature photoluminescence emission measured around 1540 nm within a broad (460 nm to 600 nm) wavelength band. Associated modeling studies showed that the effective cross section for Er excitation in the SiC0.5O1.0:Er matrix was approximately four orders of magnitude larger than its analog for direct optical excitation of Er ions.

Download Full-text

Influence of High-Calcium Ash Composition on the Composite Binders’ Properties

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.316.1019 ◽

2021 ◽

Vol 316 ◽

pp. 1019-1024

Author(s):

O. A. Ignatova ◽

A. A. Dyatchina

Keyword(s):

Mechanical Properties ◽

Chemical Composition ◽

Cement Stone ◽

Normal Density ◽

Fine Aggregate ◽

Equivalent Amount ◽

High Calcium ◽

Composition Structure ◽

Kinetics Of ◽

Positive Effect

The paper presents the studies’ results of chemical composition, structure, and physico-mechanical properties of high-calcium ashes from the Kansk-Achinsk coals (2017-2019 selection). It was found that ash has a complex poly-mineral composition and contains hydraulically active minerals and oxides of СаОfr, β-C2S, CA, C3A, C4AF, C2F, CaSO4. According to the content of CaOfr, MgO does not meet standards’ requirements. The uniformity of the volume change is maintained by the composition with 50% of cement. The structure and hardening kinetics of ash and ash-cement stone compositions, obtained from the test of normal density, were analyzed. It was established that the hardening of compositions with ash from the Kansk-Achinsk coals was largely influenced by ash minerals. An equivalent amount of cement in composite binders cannot be replaced. In order to obtain a positive effect, compositions with ash instead cement of no more than 30% and a part of fine aggregate, without exceeding the ratio of ash: cement = 1: 1, should be used.

Download Full-text

Relationship between the Optical Properties and Chemical Composition of Urban Aerosol Particles in Lithuania

Advances in Meteorology ◽

10.1155/2018/8674173 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Julija Pauraite ◽

Kristina Plauškaitė ◽

Vadimas Dudoitis ◽

Vidmantas Ulevicius

Keyword(s):

Optical Properties ◽

Chemical Composition ◽

Organic Aerosol ◽

Single Scattering ◽

Chemical Compositions ◽

Spectra Analysis ◽

Average Value ◽

Aerosol Mass ◽

In Situ Investigation

In situ investigation results of aerosol optical properties (absorption and scattering) and chemical composition at an urban background site in Lithuania (Vilnius) are presented. Investigation was performed in May-June 2017 using an aerosol chemical speciation monitor (ACSM), a 7-wavelength Aethalometer and a 3-wavelength integrating Nephelometer. A positive matrix factorisation (PMF) was used for the organic aerosol mass spectra analysis to characterise the sources of ambient organic aerosol (OA). Five OA factors were identified: hydrocarbon-like OA (HOA), biomass-burning OA (BBOA), more and less oxygenated OA (LVOOA and SVOOA, respectively), and local hydrocarbon-like OA (LOA). The average absorption (at 470 nm) and scattering (at 450 nm) coefficients during the entire measurement campaign were 16.59 Mm−1 (standard deviation (SD) = 17.23 Mm−1) and 29.83 Mm−1 (SD = 20.45 Mm−1), respectively. Furthermore, the absorption and scattering Angström exponents (AAE and SAE, respectively) and single-scattering albedo (SSA) were calculated. The average AAE value at 470/660 nm was 0.97 (SD = 0.16) indicating traffic-related black carbon (BCtr) dominance. The average value of SAE (at 450/700 nm) was 1.93 (SD = 0.32) and could be determined by the submicron particle (PM1) dominance versus the supermicron ones (PM > 1 µm). The average value of SSA was 0.62 (SD = 0.13). Several aerosol types showed specific segregation in the SAE versus SSA plot, which underlines different optical properties due to various chemical compositions.

Download Full-text