scholarly journals Study of electric parameters of thin porous anodic alumina layers

2021 ◽  
Vol 2103 (1) ◽  
pp. 012129
Author(s):  
E N Muratova ◽  
S S Nalimova ◽  
A A Bobkov ◽  
V A Moshnikov
Keyword(s):  
Aluminum Foil ◽  
Adsorbed Water ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Force Microscopy ◽  
Porous Layers ◽  
Sensor Applications ◽  
Atomic Force ◽  
Heat Treated ◽  
Electric Parameters

Abstract Currently, the study of the electric parameters of porous anodic alumina (PAA) layers is of interest for sensor applications (humidity, DNA, etc.). PAA layers are synthesized using electrochemical anodizing of aluminum foil in potentiostatic mode with an aqueous solution of sulfuric acid and glycerin as an electrolyte. The surface morphology of the layers was studied by atomic force microscopy. The electric characteristics were studied using impedance spectroscopy at room temperature and under heating. An increase in the impedance of the heat-treated PAA sample was found, as well as an increase in the impedance with an increase in the measurement temperature. The results are explained by the influence of adsorbed water molecules on the electric characteristics of porous layers.

Enhanced electrochromic properties of heat treated nanostructured tungsten trioxide thin films

2008 ◽  
Vol 23 (1) ◽  
pp. 274-280 ◽  
Author(s):  
Gisia Beydaghyan ◽  
Jean-Luc M. Renaud ◽  
Georges Bader ◽  
P.V. Ashrit
Keyword(s):  
Tungsten Trioxide ◽  
Thermal Evaporation ◽  
Infrared Region ◽  
Glancing Angle Deposition ◽  
Evaporation Chamber ◽  
Force Microscopy ◽  
Atomic Force ◽  
Heat Treated ◽  
Glancing Angle ◽  
Angle Deposition

Nanostructured tungsten trioxide films were fabricated with the technique of glancing angle deposition (GLAD) in a thermal evaporation chamber with a base pressure of 1.3 × 10−4 Pa. Films were deposited at vapor incidence angles of 0°, 20°, 40°, and 50° with film thickness varying between 160 and 200 nm, as determined by spectroscopic ellipsometry. After deposition, samples were heated for 1 h in air at 400 °C and were subsequently intercalated with small amounts (5 to 15 nm) of lithium by dry lithiation, a technique developed in our laboratory. Compared with our previous work on as-deposited nanostructured films, these samples showed significantly enhanced coloration in the infrared region. It was found that the films exhibited an absorption- based coloration in the lower wavelengths as well as an increased reflection in the infrared region. Morphological investigation by atomic force microscopy (AFM) showed grain agglomeration and increased surface roughness upon heating. Our studies further indicate that grain agglomeration significantly contributes to the superior coloration properties of the films.

Sputter Deposition of Self-Organized Nanoclusters Through Porous Anodic Alumina Templates

2007 ◽  
Vol 7 (2) ◽  
pp. 641-646 ◽  
Author(s):  
Smita Gohil ◽  
Ramesh Chandra ◽  
Bhagyashree Chalke ◽  
Sangita Bose ◽  
Pushan Ayyub
Keyword(s):  
Ambient Pressure ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Average Pore ◽  
Self Organized ◽  
Atomic Force ◽  
Sputter Deposited ◽  
Anodic Alumina Templates ◽  
Hexagonally Ordered ◽  
Ordered Porous

Silver nanoparticles were sputter deposited through self organized hexagonally ordered porous anodic alumina templates that were fabricated using a two-step anodization process. The average pore diameter of the template was 90 nm and the interpore spacing was 120 nm. Atomic force microscope studies of the sputter-deposited silver nanoparticle array on a Si substrate indicate an approximate replication of the porous anodic alumina mask. The nature of the deposition depends strongly on the process parameters such as sputtering voltage, ambient pressure and substrate temperature. We report a detailed study of the sputtering conditions that lead to an optimal deposition through the template.

Formation of Porous Anodic Alumina from Impure Aluminum Foil in Inorganic Acids

2015 ◽  
Vol 1112 ◽  
pp. 89-93
Author(s):  
Ahmad Nurrudin ◽  
Brian Yuliarto ◽  
Suyatman ◽  
Agung Sriwongo
Keyword(s):  
Room Temperature ◽  
Porous Alumina ◽  
Aluminum Foil ◽  
Average Diameter ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Sulfate Electrolyte ◽  
Average Pore ◽  
Interpore Distance ◽  
Inorganic Acids

The morphology of porous anodic alumina (PAA) formed by anodizing in inorganic electrolytes is reported. An impure aluminum was anodized in sulfuric acid, phosphoric acid and chromic acidat room temperature with a constant applied potential 2 – 30 V. The formation of porous anodic alumina was carried out by one and two steps anodization. It is clearly noted that anodizing impure aluminum at room temperature provide higher kinetic of oxide dissolution compared to oxide growth. Two steps anodizing aluminum in sulfate electrolyte always resulted in random porous alumina, while phosphate electrolyte provided strong anodization producing irregular porous alumina with average diameter of 61.6 nm. Two steps anodizing aluminum in chromate electrolyte produce better pore ordering with relatively large size pore distributions. The average pore diameter of alumina increases linearly with applied voltage, with proportionality factor lp 0.83 nmV-1. Annealing the sample increased the interpore distance, removed stresses providing lower activation energy for pore formation.

scholarly journals Peculiarities of Photoluminescence in Porous Silicon Prepared by Metal-Assisted Chemical Etching

ISRN Optics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Igor Iatsunskyi ◽  
Valentin Smyntyna ◽  
Nykolai Pavlenko ◽  
Olga Sviridova
Keyword(s):  
Porous Silicon ◽  
Chemical Etching ◽  
Etching Time ◽  
Force Microscopy ◽  
Porous Layers ◽  
Atomic Force ◽  
Silicon Nanostructure ◽  
Metal Assisted Chemical Etching ◽  
Concentrated Solution ◽  
P Type

Photoluminescent (PL) porous layers were formed on p-type silicon by a metal-assisted chemical etching method using H2O2 as an oxidizing agent. Silver particles were deposited on the (100) Si surface prior to immersion in a solution of HF and H2O2. The morphology of the porous silicon (PS) layer formed by this method was investigated by atomic force microscopy (AFM). Depending on the metal-assisted chemical etching conditions, the macro- or microporous structures could be formed. Luminescence from metal-assisted chemically etched layers was measured. It was found that the PL intensity increases with increasing etching time. This behaviour is attributed to increase of the density of the silicon nanostructure. It was found the shift of PL peak to a green region with increasing of deposition time can be attributed to the change in porous morphology. Finally, the PL spectra of samples formed by high concentrated solution of AgNO3 showed two narrow peaks of emission at 520 and 550 nm. These peaks can be attributed to formation of AgF and AgF2 on a silicon surface.

scholarly journals Structural and Morphological Properties of As-Deposited and Heat Treated Blended Graphene Oxide / Poly(3,4-Ethylenedioxythiophene)-Poly(Styrenesulfonate) Thin Films

2021 ◽  
pp. 4416-4424
Author(s):  
Saja Qasim ◽  
Ameer F. AbdulAmeer ◽  
Ali H A Jalaukhan
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Xrd Analysis ◽  
Morphological Properties ◽  
Sem Images ◽  
Force Microscopy ◽  
Atomic Force ◽  
Heat Treated ◽  
Spin Coater

    In this study the as-deposited and heat treated at 423K of conductive blend graphene oxide (GO)/ poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) thin films was prepared with different PEDOT:PSS concentration (0, 0.25, 0.5, 0.75 and 1)w/w on pre-cleaned glass substrate by spin coater. The XRD analysis indicate the existence of the preffered peak (001) of GO around 2θ=8.24° which is domain in all GO/ PEDOT:PSS films characterized for GO, this result approve the good quality of the PEDOT:PSS dispersion in GO, this peak shifted to the lower 2θ with increasing PEDOT:PSS concentration and after annealing process. The scanning electron microscopy (SEM) images and atomic force microscopy (AFM) clearly show the GO flakes and go to disappear with increasing the PEDOT:PSS concentration. 

Morphology Studies of SWCNT Dispersed in Conducting Polymer as Potential Sensing Materials

2021 ◽  
Vol 317 ◽  
pp. 189-194
Author(s):  
Nurul Syahirah Nasuha Sa'aya ◽  
Siti Zulaikha Ngah Demon ◽  
Norli Abdullah ◽  
Norhana Abdul Halim
Keyword(s):  
Conducting Polymer ◽  
Electronic Band ◽  
Force Microscopy ◽  
Sensor Applications ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Nanostructure Surface ◽  
High Resolution Images ◽  
Walled Carbon Nanotubes ◽  
Polymer Wrapping

Novel electronic nanomaterial, the carbon nanotube (CNT) has emerged in many sensor applications as such its state dispersion has considerable importance to ensure the sustainability of its electronic properties. In this paper, we reported a state of art conductivity mapping on nanostructure surface of single walled carbon nanotubes (SWCNT) and poly(3-hexylthiophene-2,5-diyl), (P3HT) as potential sensing film. This composite is proposed to give selective analyte anchoring across the film as well as improved carrier mobility. The easy solution processing method was chosen to produce non-covalently wrapped conducting polymer onto the surface of SWCNT. We successfully observed high resolution images of the SWCNT walls that indicated increase of the thickness due to polymer wrapping. The image obtained from conductivity atomic force microscopy (CAFM) show the film’s electrical distribution that correlated with the observed nanostructure of film. Supporting optical characteristics of the nanocomposite obtained from UV-Vis spectroscopy and Raman spectroscopy discussed the morphology of the polymer wrapping and the state of dispersion of the polymer and the nanotubes. It is hypothesized the filament structures made by P3HT/SWCNT can give better sensing performance due to modification of π-π electronic band of SWCNT.

Frequency-Modulated Non-contact Atomic Force Microscopy Study of Heat-Treated Oxide Surface with Organic Molecules

2006 ◽  
Vol 45 (3B) ◽  
pp. 2045-2048
Author(s):  
Shukichi Tanaka ◽  
Hitoshi Suzuki ◽  
Mitsuru Inada ◽  
Toshiya Kamikado ◽  
Shinro Mashiko
Keyword(s):  
Atomic Force Microscopy ◽  
Organic Molecules ◽  
Microscopy Study ◽  
Oxide Surface ◽  
Atomic Force Microscopy Study ◽  
Force Microscopy ◽  
Atomic Force ◽  
Heat Treated

Epitaxial growth of PbTiO3 thin films on (001) SrTiO3 from solution precursors

1995 ◽  
Vol 10 (3) ◽  
pp. 680-691 ◽  
Author(s):  
Andreas Seifert ◽  
Fred F. Lange ◽  
James S. Speck
Keyword(s):  
Thin Films ◽  
Stable Phase ◽  
X Ray Diffraction ◽  
Amorphous Precursor ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Heat Treated ◽  
Film Substrate

A mixed alkoxide liquid precursor was used to form epitaxial PbTiO3 thin films by spin-coating on cubic (001) SrTiO3 substrates. The films were heat-treated at temperatures between 380 °C/1 h and 800 °C/1 h. X-ray diffraction, atomic force microscopy, scanning and transmission electron microscopy were used to characterize the microstructure of the films and to evaluate the epitaxial phenomena. At ∼400 °C/1 h, a polycrystalline, metastable Pb-Ti fluorite crystallizes from the pyrolyzed amorphous precursor. At slightly higher temperatures (∼420 °C/1 h), the thermodynamically stable phase with the perovskite structure epitaxially nucleates at the film/substrate interface. A small number of epitaxial grains grow through the film toward the surface and consume the nanocrystalline fluorite grains. Coarsening of the perovskite grains leads to a reduction in mosaic spread during further heating. Pores, which concurrently coarsen with grain growth, produce a pitted surface as they disappear from within the film. At 800 °C/1 ha dense epitaxial PbTiO3 film with a smooth surface is observed. Parameters governing the formation of a- and c-domains are discussed as well as the small tilts of the domain axes away from the substrate normal.

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