scholarly journals Влияние отжига на свойства слоев Ge : Sb/Si(001) с концентрацией сурьмы выше уровня ее равновесной растворимости в германии

2019 ◽  
Vol 53 (7) ◽  
pp. 897
Author(s):  
Д.В. Юрасов ◽  
Н.А. Байдакова ◽  
М.Н. Дроздов ◽  
Е.Е. Морозова ◽  
М.А. Калинников ◽  
...  
Keyword(s):  
Bulk Diffusion ◽  
Luminescent Properties ◽  
Sample Surface ◽  
Solubility Limit ◽  
Electrical And Optical Properties ◽  
Annealing Temperatures ◽  
Wet Chemical ◽  
Dopant Atoms ◽  
The Impact ◽  
Photoluminescence Response

The impact of rapid thermal treatment on electrical and luminescent properties of Ge:Sb/Si(001) layers which have Sb concentration much higher than the equilibrium solubility limit was investigated. Local modifications of such properties throughout the structure’s depth were revealed using precise wet chemical etching. It was obtained that at relatively low annealing temperatures ( 500°С) the changes of electron concentration and photoluminescence response may occur without any remarkable diffusion-related redistribution of dopant atoms. For the relatively high ( 700°С) annealing temperatures the changes of electrical and optical properties after anneal are caused by the significant Sb bulk diffusion and desorption from the sample surface. In particular Sb bulk diffusion leads to the formation of doped regions in the initially undoped areas which further contribute to the resulting structure conductivity and its photoluminescence signal.

scholarly journals The impact of cold deformation, annealing temperatures and chemical assays on the mechanical properties of platinum

2010 ◽  
Vol 46 (1) ◽  
pp. 51-57 ◽  
Author(s):  
B. Trumic ◽  
D. Stankovic ◽  
A. Ivanovic
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Annealing Temperature ◽  
Cold Deformation ◽  
Platinum Metals ◽  
Deformation Degree ◽  
Annealing Temperatures ◽  
Flow Limit ◽  
The Impact ◽  
Constant Deformation

In order to form the necessary data base on platinum and platinum metals, certain tests were carried out on platinum samples of different purity of 99.5%, 99.9% and 99.99%. The degree of cold deformation, annealing temperature and chemical assays were tested as well as their impact on the mechanical properties of platinum. The Vickers hardness (HV) values were determined with different deformation degree, starting from annealing temperatures for platinum of different purity and tensile strength (Rm), flow limit (Rp0,2) and elongation (A) in the function of annealing temperatures and annealing time at a constant deformation degree.

Effects of As Doping on Properties of ZnO Films

2001 ◽  
Vol 692 ◽  
Author(s):  
K. S. Huh ◽  
D. K. Hwang ◽  
K. H. Bang ◽  
M. K. Hong ◽  
D. H. Lee ◽  
...  
Keyword(s):  
Optical Properties ◽  
Secondary Ion Mass Spectrometry ◽  
Annealing Treatment ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Electrical And Optical Properties ◽  
As Doping ◽  
Dopant Atoms ◽  
Increasing Temperature ◽  
Secondary Ion

AbstractA series of ZnO thin films with various deposition temperatures were prepared on (100) GaAs substrates by radio-frequency magnetron sputtering using ZnO target. The ZnO films were studied by field emission scanning electron microscope(FESEM), x-ray diffraction(XRD), photoluminescence(PL), cathodoluminescence(CL), and Hall measurements. The structural, optical, and electrical properties of the films were discussed as a function of the deposition temperature. With increasing temperature, the compressive stress in the films was released and their crystalline and optical properties were improved. From the depth profile of As measured by secondary ion mass spectrometry(SIMS), As doping was confirmed, and, in order to activate As dopant atoms, post-annealing treatment was performed. After annealing treatment, electrical and optical properties of the films were changed.

scholarly journals Dependence of track etching kinetics on chemical reactivity around the ion path

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
S. A. Gorbunov ◽  
R. A. Rymzhanov ◽  
A. E. Volkov
Keyword(s):  
Chemical Reactivity ◽  
Quantitative Description ◽  
Sample Surface ◽  
Numerical Approach ◽  
Heavy Ion ◽  
Ion Trajectory ◽  
Track Etching ◽  
Wet Chemical ◽  
Kinetics Of ◽  
Account Variation

Abstract Etching kinetics of swift heavy ions (SHI) tracks in olivine is investigated in frame of experimentally verified numerical approach. The model takes into account variation of induced chemical reactivity of the material around the whole ion trajectory with the nanometric accuracy. This enables a quantitative description of wet chemical etching of SHI tracks of different lengths and orientations towards to the sample surface. It is demonstrated that two different modes of etching, governed by diffusion of etchant molecules and by their reaction with the material must be observed in experiments using techniques with different resolution thresholds. Applicability limits of the optical microscopy for detection of heavy ion parameters by measuring of the lengthwise etching rates of the ion track are discussed.

Optimising the Growth of Few-Layer Graphene on Silicon Carbide by Nickel Silicidation

2013 ◽  
Vol 740-742 ◽  
pp. 121-124 ◽  
Author(s):  
Enrique Escobedo-Cousin ◽  
Konstantin Vassilevski ◽  
Toby Hopf ◽  
Nick G. Wright ◽  
Anthony O’Neill ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Sample Surface ◽  
Device Fabrication ◽  
Solid Phase Epitaxy ◽  
X Ray ◽  
Graphene Films ◽  
Few Layer Graphene ◽  
The Impact

Few-layers graphene films (FLG) were grown by local solid phase epitaxy on a semi-insulating 6H-SiC substrate by annealing Ni films deposited on the Si and C-terminated faces of the SiC. The impact of the annealing process on the final quality of the FLG films is studied using Raman spectroscopy. X-ray photoelectron spectroscopy was used to verify the presence of graphene on the sample surface. We also demonstrate that further device fabrication steps such as dielectric deposition can be carried out without compromising the FLG films integrity.

Luminescence in ZnO Quantum Particles

2004 ◽  
Vol 19 (3) ◽  
pp. 737-740 ◽  
Author(s):  
B.S. Bendre ◽  
Shailaja Mahamuni
Keyword(s):  
Zinc Oxide Nanoparticles ◽  
Luminescent Properties ◽  
Photoluminescence Excitation ◽  
Green Luminescence ◽  
Size Dependent ◽  
Uv Emission ◽  
Quantum Particles ◽  
Single Feature ◽  
Wet Chemical ◽  
Luminescence Behavior

Wet-chemical and electrochemical routes were used to synthesize zinc oxide nanoparticles showing peculiar luminescent properties. ZnO-I are the nanoparticles that show only band gap ultraviolet (UV) emission, whereas ZnO-II type nanoparticles show the defect green luminescence along with the UV emission. Photoluminescence excitation (PLE) spectra of ZnO-I nanocrystals exhibit a single feature located at about 368 nm whereas ZnO-II nanocrystals show two features in PLE: a prominent feature at about 368 nm which is size dependent and a hump at 325 nm. These results are discussed in detail in view of the luminescence behavior in ZnO quantum particles.

Synthesis and luminescent properties of La1−xNdxP5O14 nanocrystals

2014 ◽  
Vol 16 (33) ◽  
pp. 18004-18009 ◽  
Author(s):  
L. Marciniak ◽  
W. Strek ◽  
Y. Guyot ◽  
D. Hreniak
Keyword(s):  
Dopant Concentration ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Spectroscopic Properties ◽  
Branching Ratios ◽  
Luminescence Decay ◽  
The Impact

The impact of dopant concentration on spectroscopic properties of La1−xNdxP5O12 nanocrystals: the luminescence decay profiles – (a); emission spectra – (b); and luminescence branching ratios – (c).

Evaluation of Surfactants on Thermo-Physical Properties of Magnesia-Oil Nanofluid

2018 ◽  
Vol 928 ◽  
pp. 106-112 ◽  
Author(s):  
Abdallah Yousef Mohammed Ali ◽  
Ahmed H. El-Shazly ◽  
M.F. Elkady ◽  
S.E. AbdElhafez
Keyword(s):  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Mgo Nanoparticles ◽  
Transmission Electron ◽  
Wet Chemical ◽  
Cetyl Trimethyl Ammonium ◽  
Poly Vinyl Pyrrolidone ◽  
The Impact

The prime purpose of the current study was to investigate the consequence of surfactant on the kinematic viscosity, thermal conductivity, and stability of MgO-oil based nanofluid. Magnesia (MgO) nanoparticles were prepared by the wet chemical method. Structural and morphological analysis of synthesized nanoparticles were performed via X-ray diffraction (XRD) and Transmission electron microscope (TEM). Subsequently, nanofluid was prepared at a solid concentration of 0.025% in presence of various surfactants with the aid of ultrasonic technique. The impact of the different surfactants (Cetyl Trimethyl Ammonium Bromide (CTAB), Poly Vinyl Pyrrolidone (PVP), Poly Vinyl Alcohol (PVA), and Oleic Acid) on the nanofluid stability was tested. It was evident that CTAB and PVA surfactants establish the most stable prepared MgO-oil based nanofluid. The experiments revealed that the maximum UV–Vis absorbance of the solution corresponds to the dispersion of CTAB in the base fluid.

scholarly journals Influence of hydrogen on mechanical properties of pure titanium T40 (grade 2) and TA6V ELI (grade 23): a local approach of fracture

2020 ◽  
Vol 321 ◽  
pp. 09004
Author(s):  
Alexandre POLONI ◽  
Abdelali OUDRISS ◽  
Juan CREUS ◽  
Stéphane COHENDOZ ◽  
Jamaa Bouhattate ◽  
...  
Keyword(s):  
Cathodic Polarization ◽  
Hydrostatic Stress ◽  
Equivalent Plastic Strain ◽  
Pure Titanium ◽  
Tensile Tests ◽  
Solubility Limit ◽  
Local Approach ◽  
Hydrogen Charging ◽  
Β Phase ◽  
The Impact

The effect of hydrogen charging by cathodic polarization on T40 (grade 2) and TA6V ELI (grade 23) in artificial seawater appeared to be dependent on the metallurgical structure of the alloys. Mechanical tensile tests were performed on smooth samples and with different notches without and with hydrogen charging. Evolution of the fracture mode has been studied and the impact of hydrides was questioned. FEM calculation offers the opportunity to associate the local hydrostatic stress σm and equivalent plastic strain εpeq leading to the fracture and to illustrate the evolution of these conditions with hydrogen absorption and hydrides formation. Hydrogen charged by cathodic polarization appeared to have a small impact on grade 2 reducing its A%, whereas it leads to a strong embrittlement of grade 23 when the solubility limit of β-phase is exceeded and hydrides formed.

Emission, Defects and Structure of ZnO Nanocrystals obtained by Electrochemical method

MRS Advances ◽  
2017 ◽  
Vol 2 (43) ◽  
pp. 2343-2348
Author(s):  
Tetyana Torchynska ◽  
Brahim El Filali ◽  
Georgiy Polupan ◽  
Lyudmula Shcherbyna
Keyword(s):  
Emission Intensity ◽  
Hexagonal Wurtzite Structure ◽  
Ambient Air ◽  
Near Band Edge ◽  
X Ray Diffraction ◽  
Energy Dispersion Spectroscopy ◽  
Annealing Temperatures ◽  
Zno Nanocrystals ◽  
Temperature Impact ◽  
The Impact

ABSTRACTThe impact of different annealing temperatures on the crystal structure, emission and radiative defects in ZnO nanocrystals (NCs) has been investigated by means of the scanning electron microscopy (SEM), Energy dispersion spectroscopy (EDS), X-ray diffraction (XRD) and photoluminescence (PL) techniques. ZnO NCs were prepared by the anodization of zinc sheets in an electrolyte and thermal annealed at the various temperatures: 200, 240, 280, 320, 360 and 400°C for two hours in ambient air. The XRD study indicates that ZnO NCs are characterized by the hexagonal wurtzite structure.The study of annealing temperature impact on the morphology of ZnO NCs has shown that the NC size enlarges and the film crystallinity improves with increasing annealing temperatures from 200°C up to 400°C. But in the temperature range of 360-400oC the dissolution of oxygen atoms raises essentially in ZnO NC films as it follows from EDS data. Simultaneously, the near band edge (NBE) emission intensity falls down, XRD parameters of ZnO NCs change and the intensity of defect related orange and green PL bands increases owing to increasing the defect concentrations. The optimal temperatures for the ZnO NC oxidation, together with keeping the high NBE emission intensity, are estimated as 360 °C. The nature of native defects responsible for orange and green emissions in ZnO NCs has been discussed.

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