Fabrication and Comparison of Self-Organized Ag and Au Nanodots on Ti/MgO(001) Substrates

2020 ◽  
Vol 20 (5) ◽  
pp. 3231-3238
Author(s):  
Woo-Seong Kim ◽  
Kwang-Hun Oh ◽  
Tae-Hwan Kim ◽  
Seung-Hyun Shin ◽  
Tae-Woong Um ◽  
...  

We analyze and compare the differences in the dewetting phenomena and crystal structure between Ag(5.0 nm) and Au(5.0 nm) layers deposited on a Ti(1.0 nm) seed layer coated onto a MgO(001) substrate. The samples are deposited at room temperature and annealed at 350–450 °C for 5 h. The surfaces of both Ag/Ti and Au/Ti films exhibit a completely separated island structure, subsequently leading to the formation of a nanodot array after annealing. Based on atomic force microscopy (AFM) analysis, we conclude that the dewetting progression speed of Ag/Ti films is higher than that of Au/Ti films. Based on X-ray diffraction (XRD) results, the Ti thin film acts as a seed layer, assisting the epitaxial growth of fcc-Ag(001) nanodots on the MgO(001) substrate, whereas in the case of Au/Ti, the Au layer grows non-epitaxially on the MgO(001) substrate, which is related to the difference in the surface energies of Ag and Au. Furthermore, the optical absorbance spectra of the self-organized Ag and Au nanodots with the Ti seed layer are obtained in the visible light range and the optical properties of Ag and Au nanodots are compared.

2016 ◽  
Vol 689 ◽  
pp. 55-59
Author(s):  
Serge Zhuiykov

Electrical properties and morphology of orthorhombic β–WO3 nano-flakes with thickness of ~7-9 nm were investigated at the nanoscale using energy dispersive X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and current sensing force spectroscopy atomic force microscopy (CSFS-AFM, or PeakForce TUNATM). CSFS-AFM analysis established good correlation between the topography of the developed nanostructures and various features of WO3 nano-flakes synthesized via a two-step sol-gel-exfoliation method. It was determined that β–WO3 nano-flakes annealed at 550°C possess distinguished and exceptional thickness-dependent properties in comparison with the bulk, micro- and nano-structured WO3 synthesized at alternative temperatures.


1999 ◽  
Vol 583 ◽  
Author(s):  
Martin Schmidbauer ◽  
Thomas Wiebach ◽  
Helmut Raidt ◽  
Peter Schäfer ◽  
Michael hanke ◽  
...  

AbstractThe strain distribution inside and in the vicinity of coherently strained self-organized islands has been investigated by high-resolution x-ray diffraction (HRXRD). Finite element method (FEM) calculations were carried out in order to calculate the strain field, which was then used to simulate x-ray reciprocal space maps on the basis of kinematical scattering theory. For Si0 75Ge0.25 islands an abrupt increase in the Ge-concentration at about one third of the island height has been found. This behavior can be attributed to different nucleation stages during growth. Highly strained buried CdSe quantum dots (QDs) strongly influence the surrounding ZnSe matrix. From reciprocal space maps and FEM simulations we were able to estimate the shape and size of the islands. The results are in agreement with transmission electron microscopy (TEM) and UHV atomic force microscopy (AFM) data.


2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Abhinay Mishra ◽  
Pralay Maiti

Abstract Structural variation and its effect on the properties of aromatic polyurethanes (PUs) with different chain structures have been reported. Polarized optical microscopic studies of aromatic PUs demonstrate the development of micro clusters with increasing hard segment content (HSC). Higher crystallinity has also been proven from differential scanning calorimeter (DSC) and X-ray diffraction (XRD) studies. A globular pattern has been observed through atomic force microscopy (AFM) and the pattern depends on the type of diisocyanate used to prepare the PU. The difference in surface morphology is evident for two different PUs. The tensile modulus increases systematically with increasing HSC while toughness decreases, due to the presence of bigger crystallites in higher HSC polymer. Both the modulus and toughness vary on the type of diisocyanate present in PUs.


2009 ◽  
Vol 24 (10) ◽  
pp. 3044-3049 ◽  
Author(s):  
Romain Cayzac ◽  
Florence Boulc'h ◽  
Virginie Hornebecq ◽  
Thierry Djenizian ◽  
Marc Bendahan ◽  
...  

This work presents a simple electrochemical etching method to increase the surface roughness of copper indium disulphide (CIS) thin films using low concentration of hydrochloric acid. Film morphologies were investigated using scanning electron microscopy and atomic force microscopy. The structure of films was investigated using x-ray diffraction. A comparative study of optical properties of as-deposited and roughened CIS thin films by transmittance and reflectance experiments show a strong enhancement of absorbance for wavelengths between 600 and 900 nm.


Clay Minerals ◽  
2009 ◽  
Vol 44 (4) ◽  
pp. 455-468 ◽  
Author(s):  
P. Somelar ◽  
K. Kirsimäe ◽  
J. Środoń

AbstractThe composition and particle morphology of diagenetic mixed-layer illite-smectite (I-S) in the shallow buried Ordovician Kinnekulle K-bentonite were studied to understand the process of illitization in the Baltic Basin. The same K-bentonite bed from 12 different locations in the Basin was sampled and analysed by means of X-ray diffraction (XRD), atomic-force microscopy (AFM) and K-Ar dating. Illite-smectite in the samples was identified as a highly illitic R1 type illite-smectite vermiculite (high-charge smectite) mixed-layer mineral with 63–78% illitic layers. Illite-smectite was characterized by log-normally distributed thin particles with an area-weighted mean thickness varying from 1.9 to 3.6 nm and 2.1 to 3.8 nm by XRD-PVP and AFM analysis, respectively. The K-Ar diagenetic ages of the mixed-layer minerals suggest an illitization age of 370 to 420 Ma that agrees with the latest phase of the Caledonian orogeny. Illitization of the Kinnekulle bentonite was probably driven by the intrusion of K-rich fluids.


2003 ◽  
Vol 806 ◽  
Author(s):  
Senthil N Sambandam ◽  
Shekhar Bhansali ◽  
Venkat R. Bhethanabotla

ABSTRACTMicrostructures of multi-component amorphous metallic glass alloys are becoming increasingly important due to their excellent mechanical properties and low coefficient of friction. In this work, thin films of Zr-Ti-Cu-Ni-Be have been deposited by DC magnetron sputtering in view of exploring their potential technological applications in fields such as Micro Electro Mechanical Systems (MEMS). Their structure, composition, surface morphology, mechanical properties viz., hardness and Young's modulus were analyzed using X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and Nanoindentation. Influence of the deposition parameters of sputtering pressure and power upon the composition and surface morphology of these films has been evidenced by SEM, and AFM analysis, showing that such a process yields very smooth films with target composition at low sputtering pressures. These studies are useful in understanding the multicomponent sputtering process.


1996 ◽  
Vol 440 ◽  
Author(s):  
C. Lavoie ◽  
R. Martel ◽  
C. Cabral ◽  
L. A. Clevenger ◽  
J. M. E. Harper

AbstractWe demonstrate that the formation of TiSi2 for Ti films deposited on undoped Si(100) substrates leads to rougher surfaces than for Ti films deposited on undoped poly-Si substrates. The successive formations of TiSi2, C49 (high resistivity) and C54 (low resistivity) phases from titanium films deposited on either Si(100) or poly-Si substrates were monitored in situ during rapid thermal annealing using elastic light scattering, x-ray diffraction and resistance measurements. For both types of substrates, the roughening occurs only during the formation of the first TiSi2, phase (C49) by light scattered from lateral length scales of ˜0.5 μm. Atomic force microscopy (AFM) images. quantified using Fourier filtering, are consistent with the light scattering results.


2020 ◽  
Vol 38 (2) ◽  
pp. 328-333
Author(s):  
Kimia Nikpasand ◽  
Seyed Mohammad Elahi ◽  
Amir Hossein SarI ◽  
Arash Boochani

AbstractCopper (Cu) and nickel (Ni) nanoparticles have been grown simultaneously on glass and silicon substrates by RF sputtering method to form three Cu/Ni nanocomposites at different deposition times. The existence of Cu and Ni peaks in the X-ray diffraction (XRD) profiles confirms the crystalline structure of samples with Cu and Ni atomic content which have also been characterized by Rutherford backscattering (RBS) method. Moreover, the structural and morphological properties of the prepared nanocomposites have been compared with respect to their morphologies by means of atomic force microscopy (AFM) analysis. In order to compare the surface roughness over different spatial frequency ranges and evaluate surface quality, power spectral density (PSD) of each sample has been extracted from AFM data and also, the experimental and theoretical results have been compared. The fractal nature of these nanocomposites has been finally discussed.


2011 ◽  
Vol 264-265 ◽  
pp. 1383-1388
Author(s):  
Mehdi Ebadi ◽  
Wan Jeffrey Basirun ◽  
Yatimah Alias

This paper focuses on the electrodeposition of nickel from a Ni Watts solution in the presence and absence of a permanent parallel magnetic field (PPMF) to the cathode surface. It was found that the difference between the mass deposition were enhanced in the presence of PPMF and absence of a PPMF (B = 4.4 T) with increase of current density ( m= 0.413 to 4.173 mg cm2 in 6 min). The thickness of deposited layers with PPMF was smaller than without PPMF, therefore higher density of electrodeposited layers can be brought upon by the application of PPMF. The corrosion behavior of samples was tested in the presence and absence of a PPMF (9T). The Polarization resistance was reduced in the presence of the PPMF. The deposited layers were characterized by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Atomic force Microscopy (AFM).


1997 ◽  
Vol 467 ◽  
Author(s):  
F. Wang ◽  
D. Wolfe ◽  
G. Lucovsky

ABSTRACTThis study reports on a method to reduce the thermal crystallization time and temperature of amorphous silicon films by initially depositing an ultra thin μc-Si:H seed layer. After rapid thermal annealing (RTA), films were characterized by means of Raman spectroscopy, x-ray diffraction, reflection high energy electron diffraction, atomic force microscopy, and dark and photocurrent. The results show that the microcrystalline particles in the seed layer act as nucleation centers, promoting crystallization of a-Si:H at lower temperatures and at shorter times, compared to a-Si:H films deposited without any seed layer. Additionally, it was found that the seed layer affects the orientation of the crystallized films. The dark current increases abruptly over 4 orders of magnitude in the first 15 second anneal, then decreases as the time increases, and tends to saturate. The photocurrent has an opposite behavior. These transport results can be understood in terms of a change in defect density and band gap shrinkage.


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