scholarly journals Sized WS2 Lamellae and their Texture Orientations Growth

2014 ◽  
Vol 11 (2) ◽  
pp. 98-101
Author(s):  
Khalil El-Hami ◽  
Cristina Louro ◽  
Albano Cavaleiro
Keyword(s):  
Thin Films ◽  
Solid Lubricant ◽  
Steel Substrate ◽  
Substrate Type ◽  
Experimental Conditions ◽  
Geometrical Size ◽  
Force Microscopy ◽  
Dc Sputtering ◽  
Atomic Force ◽  
Afm Analysis

The tungsten disulfide (WS2) thin films, considered as inert, non-toxic, non-corrosive lubrication that is resistant to most fuel solvents, is the best solid lubricant for general industry. In this paper, WS2 thin films were deposited on steel and silicon <110> type substrates by DC sputtering methods with optimized experimental conditions and parameters. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) were employed to characterize the surface morphology and determine the geometrical size of WS2 lamellae or microtubes. The investigation showed that both SEM and AFM analysis revealed oriented WS2 crystalline lamellae on silicon substrate while they are entangled on the steel substrate. This result leads to say precociously that the WS2 thin films deposition depend on the substrate type. Moreover, using the AFM results, we could determine the average lamella (or microtube) size which has from 200 nm to 500 nm in width and from 1mm to 1.5mm in length. The EDS tool allows attaining the composition of deposited WS2 where the tungsten and the disulfide represent about 40 and 55%, respectively.

Synthesis and Characterization of Amorphous Metallic Alloy Thin Films for MEMS Applications

2003 ◽  
Vol 806 ◽  
Author(s):  
Senthil N Sambandam ◽  
Shekhar Bhansali ◽  
Venkat R. Bhethanabotla
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Surface Morphology ◽  
X Ray Diffraction ◽  
Micro Electro Mechanical Systems ◽  
Force Microscopy ◽  
Target Composition ◽  
Atomic Force ◽  
Deposition Parameters ◽  
Afm Analysis

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.

Deposition mechanism of nanostructured thin films from tetrafluoroethylene glow discharges

2005 ◽  
Vol 77 (2) ◽  
pp. 399-414 ◽  
Author(s):  
A. Milella ◽  
F. Palumbo ◽  
P. Favia ◽  
G. Cicala ◽  
R. d’Agostino
Keyword(s):  
Thin Films ◽  
Film Growth ◽  
Water Repellency ◽  
High Water ◽  
Experimental Conditions ◽  
Deposition Mechanism ◽  
Force Microscopy ◽  
Glow Discharges ◽  
Atomic Force ◽  
Surface Migration

Nanostructured polytetrafluoroethylene (PTFE)-like thin films can be deposited, in certain experimental conditions, by modulated discharges fed with tetrafluoroethylene (TFE). These coatings are characterized by a unique morphology consisting of highly twisted micron-long ribbons, which leads to an extremely high water repellency of the surface. In the present work, the diagnostics of the plasma phase is presented, coupled with that of the coating, in order to understand the film growth mechanism in different discharge regimes. When the duty cycle (DC) is increased in modulated C2F4 plasmas, the monomer depletion increases, too, and many recombination reactions take place at progressively higher rates, resulting in the formation of CF4, C2F6, C3F6, C3F8, and C4F10; the formation of powders in the homogeneous phase, however, was never evidenced. The modulation of C2F4 plasmas strongly affects the morphology of the resulting coating, as revealed by atomic force microscopy (AFM), ranging from bumpy to ribbon-like structures. The latter, moreover, are found to be more PTFE-like with respect to the remaining part of the film. In the last part of the paper, a deposition mechanism is proposed, where low radical densities in the plasma and surface migration of the precursors are the keys for the growth of ribbon-like structures.

Chiral habit selection on nanostructured epitaxial quartz films

2015 ◽  
Vol 179 ◽  
pp. 227-233 ◽  
Author(s):  
Adrián Carretero-Genevrier ◽  
Martí Gich ◽  
Laura Picas ◽  
Clément Sanchez ◽  
Juan Rodriguez-Carvajal
Keyword(s):  
Thin Films ◽  
Computer Assisted ◽  
Epitaxial Thin Films ◽  
Force Microscopy ◽  
Chiral Selection ◽  
Si Substrates ◽  
Surface Energies ◽  
Atomic Force ◽  
System P ◽  
Afm Analysis

Understanding the crystallization of enantiomorphically pure systems can be relevant to diverse fields such as the study of the origins of life or the purification of racemates. Here we report on polycrystalline epitaxial thin films of quartz on Si substrates displaying two distinct types of chiral habits that never coexist in the same film. We combine Atomic Force Microscopy (AFM) analysis and computer-assisted crystallographic calculations to make a detailed study of these habits of quartz. By estimating the surface energies of the observed crystallites we argue that the films are enantiomorphically pure and we briefly outline a possible mechanism to explain the habit and chiral selection in this system.

CARBON ION IRRADIATION EFFECTS ON PULSED LASER DEPOSITED TITANIUM NITRIDE THIN FILMS

2015 ◽  
Vol 22 (02) ◽  
pp. 1550020 ◽  
Author(s):  
KHALIQ MAHMOOD ◽  
SHAZIA BASHIR ◽  
MAHREEN AKRAM ◽  
ASMA HAYAT ◽  
FAIZAN-Ul-HAQ ◽  
...  
Keyword(s):  
Thin Films ◽  
Ion Irradiation ◽  
Pulsed Laser ◽  
X Ray Diffraction ◽  
Irradiation Effects ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Analysis ◽  
Higher Doses

Pulse laser deposited thin films of TiN are irradiated by 1 MeV carbon (C+) ions beam for various doses ranging 0.4 to 2.8 × 1014 ions/cm2. Atomic force microscopy (AFM) analysis reveals the formation of hillocks like structures after ion irradiation. X-ray diffraction (XRD) investigations show that the film crystallinity increases for lower doses ranging from 0.4 to 1.2 × 1014 ions/cm2 and decreases for higher doses (2 to 2.8 × 1014 ions/cm2) of ions. No new bands are identified from Raman spectroscopy. However, a noticeable change in microhardness has been observed. The hillock densities as well as hardness are strongly dependent upon ion dose.

Structural, morphological, and optoelectrical characterization of Bi2S3 thin films grown by co-evaporation

2016 ◽  
Vol 30 (06) ◽  
pp. 1650066 ◽  
Author(s):  
F. Mesa ◽  
C. A. Arredondo ◽  
W. Vallejo
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Experimental Conditions ◽  
Soda Lime Glass Substrate ◽  
Text Type ◽  
Force Microscopy ◽  
Atomic Force

This work presents the results of synthesis and characterization of polycrystalline [Formula: see text]-type Bi2S3 thin films. The films were grown through a chemical reaction from co-evaporation of their precursor elements in a soda-lime glass substrate. The effect of the experimental conditions on the optical, morphological structural properties, the growth rate, and the electrical conductivity [Formula: see text] was studied through spectral transmittance, X-ray diffraction (XRD), atomic force microscopy (AFM) and [Formula: see text] versus [Formula: see text] measurements, respectively. The results showed that the films grow only in the orthorhombic Bi2S3 bismuthinite phase. It was also found that the Bi2S3 films present an energy band gap [Formula: see text] of about 1.38 eV. In addition to these results, the electrical conductivity of the Bi2S3 films was affected by both the transport of free carriers in extended states of the conduction band and for variable range hopping transport mechanisms, each one predominating in a different temperature range.

Atomic force microscopy of in situ deformed nickel thin films

1999 ◽  
Vol 353 (1-2) ◽  
pp. 194-200 ◽  
Author(s):  
C. Coupeau ◽  
J.F. Naud ◽  
F. Cleymand ◽  
P. Goudeau ◽  
J. Grilhé
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Force Microscopy ◽  
Nickel Thin Films ◽  
Atomic Force

scholarly journals Topological, chemical and electro-optical characteristics of riboflavin-doped artificial and natural DNA thin films

2018 ◽  
Vol 5 (2) ◽  
pp. 171179 ◽  
Author(s):  
Bramaramba Gnapareddy ◽  
Sreekantha Reddy Dugasani ◽  
Junyoung Son ◽  
Sung Ha Park
Keyword(s):  
Thin Films ◽  
Photonic Devices ◽  
Uv Absorption ◽  
Optical Characteristics ◽  
Force Microscopy ◽  
Atomic Force ◽  
Functionalized Nanomaterials ◽  
Amorphous Structures ◽  
The Fourier Transform ◽  
Immense Potential

DNA is considered as a useful building bio-material, and it serves as an efficient template to align functionalized nanomaterials. Riboflavin (RF)-doped synthetic double-crossover DNA (DX-DNA) lattices and natural salmon DNA (SDNA) thin films were constructed using substrate-assisted growth and drop-casting methods, respectively, and their topological, chemical and electro-optical characteristics were evaluated. The critical doping concentrations of RF ([RF] C , approx. 5 mM) at given concentrations of DX-DNA and SDNA were obtained by observing the phase transition (from crystalline to amorphous structures) of DX-DNA and precipitation of SDNA in solution above [RF] C . [RF] C are verified by analysing the atomic force microscopy images for DX-DNA and current, absorbance and photoluminescence (PL) for SDNA. We study the physical characteristics of RF-embedded SDNA thin films, using the Fourier transform infrared spectrum to understand the interaction between the RF and DNA molecules, current to evaluate the conductance, absorption to understand the RF binding to the DNA and PL to analyse the energy transfer between the RF and DNA. The current and UV absorption band of SDNA thin films decrease up to [RF] C followed by an increase above [RF] C . By contrast, the PL intensity illustrates the reverse trend, as compared to the current and UV absorption behaviour as a function of the varying [RF]. Owing to the intense PL characteristic of RF, the DNA lattices and thin films with RF might offer immense potential to develop efficient bio-sensors and useful bio-photonic devices.

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