scholarly journals Homogeneous distribution of fatty ester‐based active cosmetic ingredients in hydrophilic thin films by means of nanodispersion

2020 ◽  
Vol 42 (5) ◽  
pp. 512-519
Author(s):  
Emilie Munnier ◽  
Almar Al Assaad ◽  
Stephanie David ◽  
Frédéric Mahut ◽  
Marylène Vayer ◽  
...  
Keyword(s):  
Thin Films ◽  
Fatty Ester ◽  
Homogeneous Distribution ◽  
Cosmetic Ingredients

The Sensitivity of V2O5:Sm2O3 Thin Films against NO2 Toxic Gas

2021 ◽  
Vol 19 (3) ◽  
pp. 69-77
Author(s):  
A.J. Noori ◽  
R.A. Ahmed ◽  
I.M. Ibrahim
Keyword(s):  
Thin Films ◽  
Energy Gap ◽  
Homogeneous Distribution ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Laser Method ◽  
Operation Temperature ◽  
Best Response ◽  
Diffraction Peaks ◽  
P Type

Vanadium oxide V2O5 thin films with variation doping ratios of Sm2O5 (2, 4, 6, and 8 % wt.) on corn glass and p- type silicon substrates were prepared by pulsed laser method. The X-ray diffraction peaks for V2O5 decreases with doping ratio of Sm2O3. FESEM images for V2O5 and doped thin films illustrates clusters with a homogeneous distribution in nano scale. The energy gap varied upon the increment of doping concentration, starting from 2.610 eV to 2.7 eV. Gas sensor measurement of pure and doped V2O5 demonstrated a sensitivity to NO2 gas, and the sensitivity expanded upon the increment of operation temperature. The greatest sensitivity was found to be about 99%, while best response time of 10s and recovery time of 18s were recorded using the 4% Sm2O3 sample at 50 °C.

scholarly journals Engineering of self-rectifying filamentary resistive switching in LiNbO3 single crystalline thin film via strain doping

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tiangui You ◽  
Kai Huang ◽  
Xiaomeng Zhao ◽  
Ailun Yi ◽  
Chen Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Resistive Switching ◽  
Schottky Contact ◽  
Homogeneous Distribution ◽  
Single Crystalline ◽  
Wafer Scale ◽  
Practical Applications ◽  
Crystalline Oxide ◽  
Order Of Magnitude ◽  
Switching Characteristics

AbstractThe abilities to fabricate wafer scale single crystalline oxide thin films on metallic substrates and to locally engineer their resistive switching characteristics not only contribute to the fundamental investigations of the resistive switching mechanism but also promote the practical applications of resistive switching devices. Here, wafer scale LiNbO3 (LNO) single crystalline thin films are fabricated on Pt/SiO2/LNO substrates by ion slicing with wafer bonding. The lattice strain of the LNO single crystalline thin films can be tuned by He implantation as indicated by XRD measurements. After He implantation, the LNO single crystalline thin films show self-rectifying filamentary resistive switching behaviors, which is interpreted by a model that the local conductive filaments only connect/disconnect with the bottom interface while the top interface maintains the Schottky contact. Thanks to the homogeneous distribution of defects in single crystalline thin films, highly reproducible and uniform self-rectifying resistive switching with large on/off ratio over four order of magnitude was achieved. Multilevel resistive switching can be obtained by varying the compliance current or by using different magnitude of writing voltage.

Electron Beam Dose and PMMA Thickness Dependent Circularity and Diameter Analysis of Au Nanodots

2019 ◽  
Vol >15 (5) ◽  
pp. 486-491 ◽  
Author(s):  
Furkan Kuruoğlu ◽  
Özgür Yavuzçetin ◽  
Ayşe Erol
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Electron Beam ◽  
Electron Beam Lithography ◽  
Thermal Evaporation ◽  
Exposure Dose ◽  
Homogeneous Distribution ◽  
Electrical And Optical Properties ◽  
Beam Dose ◽  
Au Nanodots

Background: The electrical and optical properties of nanoparticle-based devices depend on the shape, dimension and uniformity of these particles. Methods: In this work, we fabricated ordered Au nanodots using electron beam lithography and thermal evaporation. Au nanodot diameter and circularity varied with a changed exposure dose and resist thickness. Electron beam dose ranged from 5 fC to 200 fC for single dot patterns. Commonly used PMMA thin films of thicknesses 60 nm and 100 nm coated samples were used for investigating the resist thickness dependency with varying dose exposure. Results: The analyses of patterns show that the diameter and circularity of the Au nanodots ranged from smaller to larger diameters and from lower to higher circularities with increasing dose and resist thickness. Conclusion: The distributions of the nanodot diameter began to show Gaussian behavior at larger electron doses. Besides, single circularity value became dominant up to the medium doses and then a homogeneous distribution was observed with the increasing dose.

How much hydrogen and voids are energetically stable in silicon thin films?

2004 ◽  
Vol 813 ◽  
Author(s):  
Anna Fontcuberta i Morral ◽  
Holger Vach ◽  
Pere Roca i Cabarrocas
Keyword(s):  
Thin Films ◽  
Amorphous Silicon ◽  
Void Fraction ◽  
Hydrogen Content ◽  
Formation Energy ◽  
Hydrogenated Amorphous Silicon ◽  
Silicon Films ◽  
Homogeneous Distribution ◽  
Silicon Thin Films ◽  
Hydrogenated Amorphous

ABSTRACTWe have developed a model to account for the effects of hydrogen and voids on the structural stability of silicon thin films. The model is based on both experiments and theory. First, hydrogenated amorphous silicon films (a-Si:H) with various hydrogen contents were obtained by Plasma Enhanced Chemical Vapor Deposition. A linear correlation between hydrogen content and void fraction was observed. By tuning the deposition conditions, polymorphous silicon films with hydrogen contents up to 15%, very small void fractions (0.5%) and excellent electronic properties were also obtained. Density Functional Theory (DFT) calculations were performed to determine the formation energy for four types of silicon tetrahedra of the form Si-SinH4−n (n=1, 2, 3, 4). In our model, these tetrahedral units are considered as the building blocks of the silicon thin films. Considering a homogeneous distribution of hydrogen in the solid, the proportion of the different SiSinH4−n tetrahedra as a function of the hydrogen concentration was calculated. Then, the formation energy of hydrogenated amorphous silicon (a-Si:H) was calculated as a function of the hydrogen content and for various porosities. The model predicts that hydrogen incorporation does render the a-Si:H structure unstable for different hydrogen contents depending on the void fraction. Our results show that polymorphous silicon films with hydrogen concentrations up to 15% can be as stable as standard amorphous silicon with 2% hydrogen content, provided that the presence of hydrogen is not associated with the incorporation of porosity in the film.

Microstructure and Tribological Properties OF Co-Cr thin Films Deposited by Facing Targets Sputtering and Magnetron Sputtering Methods

1991 ◽  
Vol 239 ◽  
Author(s):  
Sadao Kadokura ◽  
Masahiko Naoe
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Tribological Properties ◽  
Columnar Structure ◽  
Plastic Substrate ◽  
Homogeneous Distribution ◽  
Columnar Microstructure ◽  
Tribological Test ◽  
Surface Profiles ◽  
Facing Target Sputtering

ABSTRACTThe tribological properties and the slid surface profiles of Co-Cr thin films deposited by Facing Targets sputtering and Magnetron sputtering methods were investigated in regard to the durability of flexible disks. Co-Cr thin films with columnless microstructure and homogeneously packed particles were much tougher than ones with columnar microstructure for tribological test. The Co-Cr films deposited by conventional Magnetron sputtering method revealed typically columnar structure, while ones deposited by Facing Target sputtering method did columnless microstructure. This indicates probably homogeneous distribution of strong bonding forces between grain boundaries throughout the films, because no brittle fracture was observed even after the delamination between a plastic substrate and the CoOx/ Co-Cr / Ni-Fe triple layers took place by application of excess stresses. It was found that difference in morphology of Co-Cr thin film between Facing Target sputtering and conventional Magnetron sputtering methods was much significant.

Synthesis and Characterization of Bi2Mn0.1V0.9O5.35-δ Thin Films

2011 ◽  
Vol 480-481 ◽  
pp. 639-643
Author(s):  
Ming Guo ◽  
Lan Ying Wu ◽  
Chang Xin Liu ◽  
Song Hua Zhou
Keyword(s):  
Thin Films ◽  
Oxygen Vacancies ◽  
Complex Impedance ◽  
Low Frequency ◽  
Deposition Process ◽  
Debye Model ◽  
Homogeneous Distribution ◽  
Solution Deposition ◽  
Complex Impedance Spectra

The Bi2Mn0.1V0.9O5.35-δ (BIMNVOX.10) thin films have been successfully deposited on the LaNiO3(LNO)/Si (100) substrates by chemical solution deposition process. The phases, morphology and electrical properties of samples have been studied. The BIMNVOX.10 films show a (00l)-preferred orientation and have a homogeneous distribution of grains. A low frequency dielectric dispersion observed in the films may be originated from the short distant diffusion of oxygen vacancies. The Cole-Cole plots of dielectric constant for the BIMNVOX.10 films appear semicircular arc with the center off the x-axis and deviate from the ideal mono-dispersive Debye model. The frequency dependent of ac conductivity for BIMNVOX.10 films follows the Joscher’s power law, mainly contributed to the grain resistivity and predicts the nature of an oxygen vacancies conduction process. The complex impedance spectra reveal that electrical process arises due to contribution from the grain interior and grain boundary effects.

Two-Phase Co–Cu Thin Films with Size Distribution of Ferromagnetic Nanostructures Optimum for Giant Magneto Resistance

2020 ◽  
Vol 20 (9) ◽  
pp. 5686-5692
Author(s):  
A. M. Mebed
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Size Distribution ◽  
Structural Evolution ◽  
Mean Free Path ◽  
Interface Roughness ◽  
Magnetic Feature ◽  
Homogeneous Distribution ◽  
Two Phase ◽  
Magneto Resistance

New thin-film microstructure, with a homogeneous distribution of a crystalized one phase Co-rich magnetic nanoparticles, embedded in a Cu-rich continuous paramagnetic matrix was obtained. This structure has many of the characteristics deemed optimal for Giant Magneto Resistance (GMR). These characteristics are; mean free path of the electrons in the matrix, granules/matrix interface roughness, the ferromagnetic concentration of the magnetic granules, and most importantly, the size distribution of the granules. This microstructure was created in Co-93at%Cu thin film, through spinodal decomposition after a short time of aging that reached equilibrium by a growth and coarsening process. Main goal of the present work was the enhancement of the microstructure in order to pinpoint the optimum microstructural and magnetic feature that improves the GMR sensitivity and stability in granular materials. Accordingly, Structural evolution of the thin films was controlled by the annealing time and temperature. Four-probe-technique was utilized to measure the GMR properties. GMR curve for a sample annealed at 150 °C was found to be stable and saturated even at low magnetic field (<5 kOe). Microstructural evolution and compositional analysis of the thin film was investigated using in-situ transmission electron microscopy (TEM) and the energy dispersive X-ray spectrometer (EDXS).

Preparation and Characterization of a Novel Organic Semiconductor Indacenedithiophene Derivative and the Corresponding Langmuir-Blodgett Thin Films

2019 ◽  
Vol 19 (11) ◽  
pp. 7244-7250 ◽  
Author(s):  
Violeta Alvarez-Venicio ◽  
Rafael O. Arcos-Ramos ◽  
José Alfonso Hernández-Rojas ◽  
Jaime Octavio Guerra-Pulido ◽  
Vladimir A. Basiuk ◽  
...  
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Organic Semiconductor ◽  
Density Functional ◽  
Stokes Shift ◽  
Langmuir Monolayers ◽  
Emission Spectra ◽  
Morphological Properties ◽  
Homogeneous Distribution ◽  
Langmuir Blodgett

The synthesis of a novel indacenedithiophene derivative (IDT-DPA) is described, which exhibits semiconducting behavior. Its properties were measured by means of UV-visible and fluorescence spectroscopies using toluene as solvent. An extinction molar coefficient of 2.05×104 M−1 cm−1 and a Stokes shift of 50 nm were obtained. A theoretical study was performed using the density functional theory, from which HOMO–LUMO band gap of 1.711 eV was calculated. IDT-DPA was deposited on the water-air interface to form Langmuir monolayers. π-A curves and hysteresis were measured showing reversibility behavior. The monolayers were transferred to glass substrates as Langmuir-Blodgett thin films. Their morphological properties were characterized by using scanning electron and atomic force microscopy, which showed that the films tend to form clusters with a homogeneous distribution. Absorption and emission spectra of the films were measured, from which the optical band gap and Stocks shift were derived. Based on the electronic properties and light emission spectra of IDT-DPA, this compound can be proposed for the applications in organic lightemitting diodes and other organic semiconductor devices.

Growing Zn0.90Co0.10O Diluted Magnetic Semiconductors by r. f. Sputtering System

2009 ◽  
Vol 1201 ◽  
Author(s):  
Musa Mutlu Can ◽  
Tezer Firat ◽  
Şadan Özcan
Keyword(s):  
Thin Films ◽  
Diluted Magnetic Semiconductors ◽  
Magnetic Semiconductors ◽  
Film Surface ◽  
Atomic Ratio ◽  
Homogeneous Distribution ◽  
Zno Films ◽  
X Ray ◽  
Preferred Direction ◽  
Sputtering System

AbstractZn0.90Co0.10O particles, synthesized by mechanical milling and thermal treatment, were pressed at 25 tons to form a 2” target for a radio frequency (r. f.) magnetron sputtering system. Using this target, thin films were deposited on (0001) oriented sapphire (α-Al2O3) substrates under 30W, 60W and 120W r. f. powers. Structural analyses of these films were done with X-Ray Diffractometer (XRD), Energy Dispersive X-Ray Spectrometry (EDS), X-Ray Photo Spectroscopy (XPS) and Atomic Force Microscopy (AFM). The ZnO films were deposited with (0002) preferred direction, which was coherent to (0001) ordered α-Al2O3. Impurity phases, such as Co clusters, CoO and Co3O4, were not detected with the surface analyses of Zn0.90Co0.10O thin films. Substituted Co atoms in the host ZnO matrix were identified by the binding energy peak of Co2p3/2, 781.3±0.4eV, and the energy difference of ∼15.61±0.03eV between Co2p1/2 and Co2p3/2. These results also proved that there were no Co clusters or Co3O4 phases in the lattice. Homogeneity of Co atoms in the lattice was shown by EDS spectra. It was understood that the higher r. f. power caused the more homogeneous distribution of Co and Zn atoms in thin films. Distributions of Co and Zn on the film surface, deposited under 120W, were found as 8.1±0.1% (normalized atomic ratio) and 91.7±0.7% (normalized atomic ratio), respectively, and the surface roughness of thin film was demonstrated by AFM figures as 14.2±0.1nm.

scholarly journals Low-Temperature Growth of ZnO Nanowires from Gravure-Printed ZnO Nanoparticle Seed Layers for Flexible Piezoelectric Devices

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1430
Author(s):  
Andrés Jenaro Lopez Garcia ◽  
Giuliano Sico ◽  
Maria Montanino ◽  
Viktor Defoor ◽  
Manojit Pusty ◽  
...  
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Zno Nanowires ◽  
Plastic Substrate ◽  
Homogeneous Distribution ◽  
Zno Nanoparticle ◽  
Gravure Printing ◽  
High Quality ◽  
Piezoelectric Devices ◽  
Seed Layers

Zinc oxide (ZnO) nanowires (NWs) are excellent candidates for the fabrication of energy harvesters, mechanical sensors, and piezotronic and piezophototronic devices. In order to integrate ZnO NWs into flexible devices, low-temperature fabrication methods are required that do not damage the plastic substrate. To date, the deposition of patterned ceramic thin films on flexible substrates is a difficult task to perform under vacuum-free conditions. Printing methods to deposit functional thin films offer many advantages, such as a low cost, low temperature, high throughput, and patterning at the same stage of deposition. Among printing techniques, gravure-based techniques are among the most attractive due to their ability to produce high quality results at high speeds and perform deposition over a large area. In this paper, we explore gravure printing as a cost-effective high-quality method to deposit thin ZnO seed layers on flexible polymer substrates. For the first time, we show that by following a chemical bath deposition (CBD) process, ZnO nanowires may be grown over gravure-printed ZnO nanoparticle seed layers. Piezo-response force microscopy (PFM) reveals the presence of a homogeneous distribution of Zn-polar domains in the NWs, and, by use of the data, the piezoelectric coefficient is estimated to be close to 4 pm/V. The overall results demonstrate that gravure printing is an appropriate method to deposit seed layers at a low temperature and to undertake the direct fabrication of flexible piezoelectric transducers that are based on ZnO nanowires. This work opens the possibility of manufacturing completely vacuum-free solution-based flexible piezoelectric devices.

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