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Articles
by
M. Sridharan |
Total Records (
6 ) for
M. Sridharan |
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K.J. Kumaresh
,
P. Deepak Raj
and
M. Sridharan
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The fabrication of thin film based capacitors with different metal electrodes
(Al, Cu) and their application towards void fraction measurement is carried
out in this study. Void fraction is a measure of empty spaces in any medium.
The void fraction is measured as capacitance in the capillary tube and processed
through embedded system. The thin film capacitor is designed on a capillary
tube through thermal evaporation technique with the above given metal elements.
Capillary tube with different diameters ranging from 5-10 mm and length of 7
inch were used and deposited with metal elements mentioned above with a small
distance between them. The capillary tube is used as insulator with metal elements
deposited above them as metal electrodes. Changes in capacitance value due to
the voids were measured through LCR/Z meter. Before coating the electrodes on
the capillary tubes, the films were characterized for their structural, morphological
and electrical properties to obtain capacitors with desired value of capacitance. |
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P. Karthick
,
Divya Vijayanarayanan
,
S. Suja
,
M. Sridharan
and
K. Jeyadheepan
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Transparent and conductive fluorine doped tin oxide thin films (FTO) were deposited on to thoroughly cleaned glass substrates by nebulized spray pyrolysis technique using di-hydrated tin (II) chloride (SnCl2.2H2O) and ammonium fluoride (NH4F) as the source of tin (Sn) and fluorine (F), respectively. The fluorine concentration was varied from 0.005-0.04 M in the steps of 0.05. The substrate temperature was constantly maintained at 350°C for all depositions. The influence of dopant concentration on the optoelectronic properties of FTO thin films was investigated using X-Ray Diffraction (XRD) analysis, Scanning Electron Micrographs (SEM), Energy Dispersive Analysis of X-rays (EDAX) spectra, optical analysis and electrical measurements. |
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M. Krishna Kumar
,
P. Deepak Raj
,
Albert Serra Torrent
,
K. Jeyadheepan
and
M. Sridharan
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Zinc oxide (ZnO) films were deposited onto glass substrates using reactive direct current magnetron sputtering technique by varying the substrate bias voltage (floating potential and -50 V) and retaining other parameters, viz., deposition time, substrate temperature, argon and oxygen flow, etc., as constant. The deposited ZnO films were doped with aluminium (Al) using thermal evaporation technique and subsequently annealed at 150°C for 2 h in ambient air. Pure and Al doped films were then investigated by X-ray diffraction (XRD), UV-Visible spectroscopy, Field-Emission Scanning Electron Microscopy (FE-SEM) and four probe method for their structural, optical, morphological and electrical properties, respectively. The films were polycrystalline in nature with hexagonal wurtzite structure. Increase in the grain size value was observed for the films deposited at -50 V substrate bias voltage as well as for the films doped with Al which in turn reduced the band gap value of the films. The band gap values of the films varied between 3.34 and 3.00 eV with respect to substrate bias voltage and Al doping. The variations in the properties of the films were correlated to the change in the micro-structural parameters due to the change in the ion energy variation influenced by the variation of substrate bias voltages. |
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S. Radhika Kathyayini
,
S. Sangeetha
and
M. Sridharan
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The polymer based nanocomposites were obtained by merging inorganic Titanium
Dioxide (TiO2) in the polymer system focusing on raising the optical
transparency and to study the photo catalytic activity. The precursor chosen
here is titanium (IV) isopropoxide which is the starting material for sol-gel
synthesis to form a TiO2 sol-gel solution. The choices of the polymers
are acrylates namely methyl metha acrylate and butyl acrylate monomers which
are copolymerized using benzoyl peroxide as initiator for enhanced copolymerization.
This study involves synthesis of TiO2 sol-gel solution and developing
TiO2 thin films coated over glass slides by spin coating technique
to improvise the transmittance efficiency characteristic of glass. The deposited
thin films were characterized for their structural, morphological, optical properties
besides the elemental composition and photo catalytic activity. The prepared
films were highly transparent were hydrophobic. The PMMA-co-PBA-TiO2
nanocomposite films exhibited good photo catalytic activity. |
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E. Sreepradha
,
Tamma Durga Bhavani
,
S. Gayathri
and
M. Sridharan
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Titanium Nitride (TiN) is an interstitial nitride with remarkable hardness,
adhesion and toughness making it ideal for thin film applications. In this work
the effect of substrate bias and substrate temperature on crystallinity, morphology,
hydrophobicity and adhesion of TiN films has been studied. The films were deposited
by dc magnetron sputtering on well-cleaned substrates of glass, silicon (100)
and stainless steel (AISISS304). The deposited films were analysed using X-ray
Diffraction (XRD), Field Emission Scanning Electron Microscope (FE-SEM), contact
angle measurement and scratch testing. Grains with globular and columnar morphology
were formed and the films were predominantly hydrophilic in nature. In the absence
of substrate bias amorphous films were formed and (111) and (200) planes appeared
with substrate heating and bias. Improved adhesion was observed at lower bias
and higher temperatures. |
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K. Pedersen
,
J. Bottiger
,
M. Sridharan
,
M. Sillassen
and
P. Eklund
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Cr2O3 and (Cr,Al)2O3 films were grown using reactive dc and inductively coupled plasma magnetron sputtering at substrate temperatures of 300-450°C. For pure chromia, α-Cr2O3 films with fiber texture were grown; the out-of-plane texture could be controlled from < 0001 > to < 101̅4>. The former texture was obtained as a consequence of competitive growth with no applied bias or inductively coupled plasma, while the latter was obtained at moderate bias (-50 V), probably due to recrystallization driven by ion-bombardment-induced strain. By reactive codeposition of Cr and Al, a corundum-structured metastable solid solution α-(Cr,Al)2O3 with Cr/Al ratios of 2-10 was grown with a dense, fine-grained morphology. Hardness and reduced elastic modulus values were in the ranges 24-27 GPa and 190-230 GPa, respectively. |
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