scholarly journals Fabrication and characterization of Si1− x Ge x nanocrystals in as-grown and annealed structures: a comparative study

2019 ◽  
Vol 10 ◽  
pp. 1873-1882 ◽  
Author(s):  
Muhammad Taha Sultan ◽  
Adrian Valentin Maraloiu ◽  
Ionel Stavarache ◽  
Jón Tómas Gudmundsson ◽  
Andrei Manolescu ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Self Assembly ◽  
Structural Changes ◽  
Ambient Atmosphere ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Interface Characteristics ◽  
Order Of Magnitude ◽  
Grown Structure

Multilayer structures comprising of SiO2/SiGe/SiO2 and containing SiGe nanoparticles were obtained by depositing SiO2 layers using reactive direct current magnetron sputtering (dcMS), whereas, Si and Ge were co-sputtered using dcMS and high-power impulse magnetron sputtering (HiPIMS). The as-grown structures subsequently underwent rapid thermal annealing (550–900 °C for 1 min) in N2 ambient atmosphere. The structures were investigated using X-ray diffraction, high-resolution transmission electron microscopy together with spectral photocurrent measurements, to explore structural changes and corresponding properties. It is observed that the employment of HiPIMS facilitates the formation of SiGe nanoparticles (2.1 ± 0.8 nm) in the as-grown structure, and that presence of such nanoparticles acts as a seed for heterogeneous nucleation, which upon annealing results in the periodically arranged columnar self-assembly of SiGe core–shell nanocrystals. An increase in photocurrent intensity by more than an order of magnitude was achieved by annealing. Furthermore, a detailed discussion is provided on strain development within the structures, the consequential interface characteristics and its effect on the photocurrent spectra.

scholarly journals Fabrication and characterization of Si1-xGex nanocrystals in as-grown and annealed structures: A comparative study

2019 ◽  
Author(s):  
Muhammad Taha Sultan ◽  
Valentin Serban Teodorescu ◽  
Jón Tómas Guðmundsson ◽  
Andrei Manolescu ◽  
Magdalena Lidia Ciurea ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Self Assembly ◽  
Structural Changes ◽  
Nano Particles ◽  
Ambient Atmosphere ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Interface Characteristics ◽  
Order Of Magnitude

Multilayer structure comprising of SiO2/SiGe/SiO2 were obtained by depositing SiO2 layers using reactive direct current magnetron sputtering (dcMS), whereas, Si and Ge were co-sputtered using dcMS and high impulse power magnetron sputtering (HiPIMS), respectively. The as-grown structures subsequently underwent rapid thermal annealing (550 – 900 °C for 1 min) in N2 ambient atmosphere. The structures were investigated using X-ray diffraction, high-resolution transmission electron microscopy along with photoconductive analysis, to explore structural changes and constituent properties. It is observed that the employment of HiPIMS facilitates the formation of SiGe nano-particles (~ 2.1 ± 0.8 nm) in the as-grown structure, and that presence of such nano-particles acts as a seed for heterogeneous nucleation, which upon annealing results in formation of periodically arranged columnar self-assembly of core-shell SiGe nanocrystals. Consequently an increase in photocurrent intensity by more than an order of magnitude was achieved by the annealing. Furthermore, a detailed discussion is provided on strain development within the structures, the consequent interface characteristics and its effect on the photocurrent spectra.

Synthesis and Characterization of Mesoporous Silica Nanoparticles Embedded Gadolinium Oxide

2011 ◽  
Vol 306-307 ◽  
pp. 1275-1279 ◽  
Author(s):  
Ning Qi Luo ◽  
Zhan Yun Huang ◽  
Ping Luo ◽  
Yuan Zhi Shao ◽  
Di Hu Chen
Keyword(s):  
Mesoporous Silica ◽  
Self Assembly ◽  
Mesoporous Silica Nanoparticles ◽  
Sol Gel ◽  
Mesoporous Structure ◽  
Gadolinium Oxide ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
The Mean

We first synthesized gadolinium oxide (Gd2O3) by a modified “polyol” strategy and then embedded it into mesoporous silica by a simple self-assembly sol-gel reaction. Scanning electron microscope (SEM) results show that the samples have good sphericity and good dispersibility. The structure of mesoporous silica was characterized by transmission electron microscopy (TEM) and small-angle X-ray diffraction (SAXRD). Results show that the mesoporous structure has not been destroyed after gadolinium oxide imbedding. The ratio of gadolinium and silica was determined by the mean of energy dispersive spectroscopy (EDS).

scholarly journals Structural characterization of Fe–C coatings prepared by reactive triode-magnetron sputtering

2010 ◽  
Vol 25 (9) ◽  
pp. 1859-1869 ◽  
Author(s):  
Isabelle Jouanny ◽  
Valérie Demange ◽  
Jaafar Ghanbaja ◽  
Elisabeth Bauer-Grosse
Keyword(s):  
Magnetron Sputtering ◽  
Gas Flow ◽  
Carbon Matrix ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Electron Energy Loss

Fe1–xCx coatings were synthesized by triode magnetron sputtering of an iron target in a methane/argon atmosphere with a large range of composition (x = 0.3 to 0.6 ± 0.06). Film surfaces were characterized by grazing incidence x-ray diffraction, scanning and transmission electron microscopies, and electron energy loss spectroscopy, to study effects of the variation of the methane gas flow rate on their structural properties. The coatings were constituted of the ε-Fe3C carbide (x = 0.3 and 0.36), in which carbon atoms are in octahedral sites, and of nanocomposite structure constituted of disordered and crystalline carbide nanograins embedded in a carbon matrix made of an amorphous and poorly crystallized graphenelike material (x = 0.55 and 0.60). In situ annealing of the nanocomposite Fe0.45C0.55 coating led to the formation of carbides θ-Fe3C and Fe7C3 (with carbon atoms in prismatic sites) and C-rich cubic carbide possibly related to the τ2-Fe2C7 compound.

Structure of Fe-Based Metallic Glass after Crystallization Process

2010 ◽  
Vol 163 ◽  
pp. 165-168 ◽  
Author(s):  
Ryszard Nowosielski ◽  
Rafał Babilas ◽  
Grzegorz Dercz ◽  
Lucjan Pająk
Keyword(s):  
Magnetic Properties ◽  
Metallic Glass ◽  
Structural Changes ◽  
Crystallization Process ◽  
X Ray Diffraction ◽  
Soft Magnetic ◽  
After Effects ◽  
Transmission Electron ◽  
Saturation Induction

The work presents a crystallization process of Fe-based amorphous alloy by characterization of the influence of annealing temperature on structural changes and magnetic properties of Fe72B20Si4Nb4 metallic glass. The studies were performed on the samples in the form of ribbons and rods. Crystallization behaviour of the studied alloy was examined by X-ray diffraction (XRD) and transmission electron microscopy (TEM) methods. The studies of soft magnetic properties of tested material involved magnetic permeability, saturation induction, coercive field and magnetic after-effects measurements.

Microscopical Study of Au Nanocrystals Self-Assembled on (100)Si and SiO2/(100)Si Substrates

2006 ◽  
Vol 959 ◽  
Author(s):  
Emanuela Piscopiello ◽  
Leander Tapfer ◽  
Marco Vittori Antisari ◽  
Pasquale Paiano ◽  
Paola Prete ◽  
...  
Keyword(s):  
Self Assembly ◽  
Au Nanoparticles ◽  
Microscopical Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Au Film ◽  
Assembly Method ◽  
Transmission Electron

ABSTRACTThis work reports on the structural characterization of Au nanocrystals directly prepared on the surface of (100)Si and 150 nm-thick SiO2 deposited (100)Si substrates, by a physical self-assembly method, consisting in the UHV evaporation of a thin Au film and its successive high temperature annealing. The morphology, orientation, and crystalline structure of Au nanocrystals were characterized by scanning and high-resolution transmission electron microscopy and X-ray diffraction, respectively. Experimental results show that the nature of the substrate strongly influences the process of Au nanocrystal formation upon heat treatment, by affecting the interaction of deposited Au with the underlying material. In the case of clean (100)Si substrates the Au strongly interacts with Si, so that Au nanoislands are obtained with a well defined epitaxial relationships with the substrate, i.e. [100]AuÐÐ[110]Si and [110]AuÐÐ[311]Si. The nanoisland shape is affected by faceting at the Au/Si interface, the Au nanocrystal being limited by the {111}, {311}, {711} and {-111} planes of Si. In the case of SiO2/(100)Si substrates spherical shaped Au nanoparticles with random crystal orientation are instead, produced.

Fabrication and Characterization of Perovskite Nanocube Ordering Structures via Capillary-Force-Assisted Self-Assembly Process

2013 ◽  
Vol 566 ◽  
pp. 285-288 ◽  
Author(s):  
Kenichi Mimura ◽  
Feng Dang ◽  
Kazumi Kato ◽  
Hiroaki Imai ◽  
Satoshi Wada ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
Capillary Force ◽  
Piezoresponse Force Microscopy ◽  
X Ray Diffraction ◽  
Ordered Structures ◽  
Force Microscopy ◽  
Assembly Method ◽  
Transmission Electron

Barium titanate (BT) and strontium titanate (ST) nanocubes which have been synthesized by hydrothermal method with surfactants were assembled in order directly on the substrates by using capillary-force-assisted self-assembly method. The ordered structures, crystallinity and orientation of the nanocubes were evaluated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning probe microscopy (SPM) and X-ray diffraction (XRD). The piezoresponse properties of the nanocubes ordering structures characterized by Piezoresponse Force Microscopy (PFM) seemed to depend on the constituents and their interface.

Deposition and characterization of AlN thin films obtained by radio frequency reactive magnetron sputtering

2014 ◽  
Vol 92 (7/8) ◽  
pp. 940-942 ◽  
Author(s):  
M.V. Pelegrini ◽  
M.A. Alvarado ◽  
M.I. Alayo ◽  
I. Pereyra
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Radio Frequency ◽  
Rutherford Backscattering Spectrometry ◽  
Pure Aluminum ◽  
Gaseous Mixture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Aluminum nitride (AlN) thin films were deposited by reactive radio frequency magnetron sputtering from pure aluminum target, onto Si (100), ultra dense flat carbon, and quartz. Series of samples were obtained varying the Ar and N2 gaseous mixture. The characterizations performed were Fourier transform infrared (FTIR), X-ray diffraction, high resolution transmission electron microscopy, visible optical absorption, Rutherford backscattering spectrometry, and residual stress measurements by Stoney’s equation. In this paper we report on the Ar/N2 ratio needed to produce preferential (002) AlN growth. Correlations between X-ray diffraction and FTIR are made for highly oriented (002) AlN films.

Structural Characterization of Ru-B 4c Multilayers Fabricated By Magnetron Sputtering

1990 ◽  
Vol 208 ◽  
Author(s):  
D. G. Stearns ◽  
R. S. Rosen ◽  
S. P. Vernon
Keyword(s):  
Magnetron Sputtering ◽  
Normal Incidence ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Detailed Structure ◽  
X Ray ◽  
Transmission Electron ◽  
Ultrathin Layers ◽  
Deposition Conditions

ABSTRACTMultilayer structures composed of alternating, ultrathin layers of Ru and B4C have been fabricated using DC magnetron sputtering. These multilayers are potentially important as normal incidence x-ray reflectors at wavelengths above the boron K-absorption edge at 65Å. The detailed structure of the layers has been characterized using x-ray diffraction and high-resolution transmission electron microscopy. It is found that, under optimized deposition conditions, continuous layers can be grown that have smooth and abrupt interfaces. The normal incidence reflectivity at x-ray wavelengths of ∼70Å has been measured, and values as high as 20% have been obtained.

Growth and Characterization of Well-Aligned RuO2/R-TiO2 Heteronanostructures on Sapphire (100) Substrates by Reactive Magnetron Sputtering

2011 ◽  
Vol 170 ◽  
pp. 78-82
Author(s):  
Hung Pin Hsu ◽  
Ying Sheng Huang ◽  
Chien Nan Yeh ◽  
Yi Min Chen ◽  
Dah Shyang Tsai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Magnetron Sputtering ◽  
Reactive Magnetron Sputtering ◽  
Reactive Magnetron ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Vertically Aligned ◽  
Xrd Patterns ◽  
Electron Diffractometry

We report the growth of well-aligned RuO2/R-TiO2 heteronanostructures on sapphire (100) substrates by reactive magnetron sputtering using Ti and Ru metal targets under different conditions. The surface morphology and structural properties of the as-deposited heteronanostructures were characterized using field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and selected-area electron diffractometry (SAED). The FESEM micrographs and XRD patterns indicated the growth of vertically aligned RuO2(001) nanotubes and twinned V-shaped RuO2(101) nanowedges (NWs) on top of R-TiO2 nanorods under different sputtering pressures. TEM and SAED characterizations of the V-shaped RuO2 NWs showed that the NWs are crystalline RuO2 with twin planes of (101) and twin direction of [ 01] at the V-junction.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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