Keywords : FTIR

Infrared Nonlinear Optical Performances of (Ga2Ge)100-x(Ga3Sb2)x (x = 15, 30, 45, 60) Thin Films

Rajnish Raj; Pooja Lohia; D. K. Dwivedi

Advanced Materials Letters, 2021, Volume 12, Issue 9, Pages 1-1
DOI: 10.5185/amlett.2021.091662

The traditional melt-quench technique was used to synthesize non-oxide (Ga2Ge)100-x(Ga3Sb2)x
(x = 15, 30, 45, 60) glass alloys. The vacuum thermal evaporation unit was used to obtain thin films of prepared sample for investigation of optical properties. SEM, XRD and DSC technique were used to find the thermal and structural properties of the materials. The linear properties like optical bandgap, extinction coefficient for prepared samples have been studied in present paper of Ge-Ga-Sb for application of optoelectronics. The impurities present in the prepared thin films were defined by FTIR transmittance spectra. The extinction coefficient (k) value decreases with increase in Sb concentration while absorption coefficient (α). It was noticed that value of energy bandgap (Eg) derived from Tauc’s plot varies from 2.9 eV to 1.25 eV. Urbach energy is inversely proportional to the bandgap of the materials. As the Sb concentration increases the band gap goes on decreases which result the increase in Urbach energy. Mott and Davis model has been used for explaining decrease in energy gap of prepared glassy alloys. 

Synthesis and Characterization of Gold Nanoparticles from Lobelia Nicotianifolia Leaf Extract and its Biological Activities

M.B. Lava; Uday M. Muddapur; B. Nagaraj

Advanced Materials Letters, 2020, Volume 11, Issue 3, Pages 1-4
DOI: 10.5185/amlett.2020.031491

Biosynthesis of gold nanoparticles is one among the best and cheap economical viable process, which is environmental friendly. The purpose of this study is to synthesis the gold nanoparticles using Lobelia nicotianifolia leaf extract and to investigate its biological activities. The synthesized gold nanoparticles were characterized by UV-vis spectroscopy, TEM, SAED, FTIR and XRD, the nanoparticles produced at maximum absorbance 532 nm. The Characterization study proved that the size and shape of AuNPs were spherical in shape, with an average size of 80 nm. Synthesized AuNPs were evaluated for various in-vitro biological studies.

Thickness Effect On Nano-multilayered Sb/As2S3 Chalcogenide Thin Films

Ramakanta Naik

Advanced Materials Letters, 2016, Volume 7, Issue 10, Pages 821-825
DOI: 10.5185/amlett.2016.6339

The nano multilayered thin films of Sb/As2S3 metal chalcogenide were prepared by thermal evaporation technique under high vacuum. The optical parameters such as optical band gap, tauc parameter, urbach energy were determined from the transmission spectra using Fourier Transform Infrared Spectroscopy. These properties are greatly influenced by the thickness of the nano layered Sb/As2S3 thin film. The Small Angle X-ray diffraction study reveals the amorphous nature of these films. The analysis reveals that the optical band gap decreases with increase in thickness due to Sb metal. The tauc parameter and urbach energy supports the optical property change. Such type of dependence is attributed to quantum size effect in semiconductors.

Rice Husks As A Sustainable Source Of High Quality Nanostructured Silica For High Performance Li-ion battery Requital By Sol-gel Method – A Review

K. Kaviyarasu; M. Jayachandran; M. Maaza; E. Manikandan; J. Kennedy

Advanced Materials Letters, 2016, Volume 7, Issue 9, Pages 684-696
DOI: 10.5185/amlett.2016.6192

The electronics industry is heavily reliant on the use of silicon in devices ranging from solar panels to circuitry. This is of growing concern due to the environmental impact of sourcing and refining the material. Thus, a green source of silicon is of vital importance to meet the growing demand for silicon in the industry. Rice husk represents an abundant source of nano silica. Currently the husk is considered a waste product that is separated from the grain during the milling process. Several methods have been trailed to extract the nano silica from rice husk. This paper reviews these current methods and presents suggestions of innovative research directions for processing techniques. This work reveals that the structural nature of superfine silica from rice husk ash is independent of the purification method, but dependent on the incineration temperature used. The paper concludes by advocating the physic-chemical process for producing high purity reactive nanosilica from rice husk. This method has the advantage of having high volume production versatility and being environmentally friendly. However, control of the morphology, shape, size, crystalline structure and chemical composition of rice husk nanostructures remains a challenge in the development of 3D nanopores arrays controllable by synthesis methods. We hope this article can provide the reader with snapshots of the recent development and future challenges.

Synergistic Effect Of Water Soluble Chitin And Iodide Ion On The Corrosion Inhibition Of Mild Steel in Acid Medium

Yesodaran Sangeetha; Sankaran Meenakshi; Chandrasekaran Sairam Sundaram

Advanced Materials Letters, 2016, Volume 7, Issue 7, Pages 587-592
DOI: 10.5185/amlett.2016.6318

The inhibition performance of water soluble chitin (WSC) and its synergistic inhibition with potassium iodide (KI) in 1 M HCl was studied using gravimetric and electrochemical measurements. From gravimetric measurement it is inferred that there is an increase in inhibition efficiency with the increased addition of inhibitor and it further stepped up to a higher value in the presence of 0.1 % KI. Polarization studies revealed that there is mixed mode of inhibition by WSC. Impedance study suggested the adsorption of the inhibitor at the interface between mild steel and acidic solution. The adsorption of inhibitor followed Frumkin isotherm. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) confirmed the co- adsorption of KI with WSC on the mild steel surface. Fourier Transform Infra-red (FTIR), Atomic Force Microscopy (AFM) and X- ray Diffraction (XRD) indicated the formation of protective film by the inhibitor on the surface of mild steel.

Impedance Spectroscopy And Conductivity Studies Of CdCl2 Doped Polymer Electrolyte

Mayank Pandey; Girish M. Joshi; Kalim Deshmukh; Jamil Ahmad

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 165-171
DOI: 10.5185/amlett.2015.5639

Polyvinyl alcohol (PVA) and Polyvinyl Pyrrolidone (PVP) based polymer electrolytes for different loading wt% of CdCl2 were prepared by solution casting. The structural complexation was confirmed and interlayer spacing (d) was evaluated by using X-ray diffraction (XRD) study. The chemical bonding between polymer and salt was identified by using Fourier transform infrared spectroscopy (FTIR) technique. The FTIR peak at 3402.43 cm -1 in addition of PVP in PVA/CdCl2 composite demonstrates the grafting between two polymers. The presence of ionic bright channels and variation in morphology for different loading wt% of CdCl2 was confirmed by scanning electron microscope (SEM) and was also verified by Atomic force microscopy (AFM) micrographs. The analysis of impedance spectroscopy represented by semicircular pattern is driven by conduction mechanism and correlated with electrical conductivity. The enhanced AC conductivity of polymer electrolyte is directly proportional to frequency (50Hz-1MHz). The maximum value of DC conductivity 1.65x10 -5 S/m evaluated from Arrhenius plots and attribute to high mobility of free charges at higher temperature. The evaluated results of structural, morphological and electrical properties of present composites make the present research good for electrochemical devices.

Green Synthesis Of Gold Nanoparticles From The Leaf Extract Of Nepenthes Khasiana And Antimicrobial Assay

B.S. Bhau; Sneha Ghosh; Sangeeta Puri; B. Borah; D.K. Sarmah; Raju Khan

Advanced Materials Letters, 2015, Volume 6, Issue 1, Pages 55-58
DOI: 10.5185/amlett.2015.5609

Synthesis of nanoparticles from various biological systems has been reported, but among all, biosynthesis of nanoparticles from plants is considered as the most suitable method. The use of plant material not only makes the process eco-friendly but also the abundance makes it more economical. The aim of this study was to investigate the ability of this plant to synthesis gold nanoparticles and study the properties of the nanoparticles thus produced. Antimicrobial activity and medicinal values of Nepenthes khasiana fascinated us to utilize it for biosynthesis of gold nanoparticles. The synthesized gold nanoparticles were characterized by UV-vis spectrophotometry, Scanning Electron Microscopy, X-ray Diffraction, Fourier Transform Infra-red Spectroscopy and Transmission Electron Microscopy. Different time intervals for the reaction with aqueous chloroauric acid solution increase in the absorbance with time and became constant giving a maximum absorbance at 599.78 nm at three hours of incubation. The results from XRD, TEM and SEM supports the biosynthesis of triangular and spherical shaped Gold nanoparticles between 50nm to 80 nm. In this study, the antimicrobial property of the AuNPS was exploited against human pathogenic micro-organisms. The results of TEM, SEM, FT-IR, UV-VIS and XRD confirm that the leaves extract of N. Khasiana can be used to produce Gold nanoparticles with significant amount of antimicrobial activity.​

Photoluminescence Properties Of Eu3+, Ce3+ Doped LaPO4 Phosphors

Niyaz Parvin Shaik; N. V. Poornachandra Rao; K. V. R. Murthy

Advanced Materials Letters, 2014, Volume 5, Issue 12, Pages 722-727
DOI: 10.5185/amlett.2014.5572

Pure LaPO4 and LaPO4: Eu (0.5 mol %) Ce (0.5 mol %) phosphors were synthesized by the solid-state reaction method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) spectra and the particle size analysis were used to characterize these samples. The XRD results reveal that the synthesized LaPO4:Eu (0.5 mol%) Ce (0.5 mol%) phosphors are well crystalline and assigned to the monoclinic structure with a main (120) diffraction peak. The calculated crystallite size of pure LaPO4 and LaPO4:Eu, Ce phosphors were 67.6nm and 64nm respectively. Upon excitation at 254nm wavelength, the emission spectrum of pure  LaPO4 phosphor emits a maximum intensity peak at 470 (blue) nm. In the emission spectrum of LaPO4:Eu 3+ Ce 3+ phosphor, the low contributions of the red (613nm) 5D0-7F2 emissions and the high intensity of the orange-red (589nm)5D0-7F1 emission results in high color purities.The most intense emissions appearing in the 580-620nm region is responsible for the strong orange-red luminescence observed in the Eu,Ce doped LaPO4 phosphor whose CIE colour coordinates are x = 0.57 and y = 0.43.Thus the prepared phosphors can be used as an orange-red emitting material in the field of illuminations and display devices.

Tb3+ Doped Sr2(BO3)Cl  Green Emitting Phosphor For Solid State Lighting

Vishal R. Panse; N.S. Kokode; S.J. Dhoble

Advanced Materials Letters, 2014, Volume 5, Issue 10, Pages 604-610
DOI: 10.5185/amlett.2014.amwc432

In this paper we present luminescence results on Tb 3+ doped Sr2(BO3)Cl green phosphor. The vibrational properties of Sr2(BO3)Cl phosphor was studied by Fourier transform infrared spectroscopy. Photoluminescence studies have been carried out to understand the mechanism of excitation and the corresponding emission in the as prepared phosphor. As the Tb 3+ ion is commonly used as an activator for the green emission, the excitation and emission spectra indicate that this phosphor can be effectively excited by 380 nm, to exhibit bright green emission centered at 546 nm corresponding to the f→f transition of Tb3 +ions.

Synthesis And Characterization Of CuO Electrospum Nanofiber Using Poly(vinyl Acetate)/Cu(CH3COO)2 Annealing Method

Seema Sharma; Rashmi Rani; Radheshyam Rai; T. S. Natarajan

Advanced Materials Letters, 2013, Volume 4, Issue 10, Pages 749-753
DOI: 10.5185/amlett.2013.2425

One dimensional nanofibers of organic and inorganic materials have been used in filters, optoelectronic devices, sensors etc. It is difficult to obtain ultra fine fibers of inorganic materials having lengths in the order of millimeter as they tend to break during formation due to thermal and other mechanical stresses. In this study, we have investigated the mechanism to prevent the defect formation and the breaking of CuO nanofibers by using optimized heat flow rates. CuO nanofibers were obtained by heat treating the poly(vinyl acetate) PVA composite fibers formed by electrospinning. The morphology and structural characteristics of prepared samples were investigated by Scanning electron microscopy, Transmission electron microscopy and X-ray diffraction. It was found that the morphology of the composite and annealed nanofibers could be influenced by the concentration of the polymer content. A lower concentration favors the formation of defects along the fiber and the number of defects reduces when the concentration is increased.

Thermal Analysis And Luminescent Properties Of Sr2CeO4 blue phosphor

Pradip Z. Zambare; K. V. R. Murthy;O. H. Mahajan; K. D. Girase

Advanced Materials Letters, 2013, Volume 4, Issue 7, Pages 577-581
DOI: 10.5185/amlett.2012.11457

In this paper we report Strontium Cerium Oxide (Sr2CeO4) blue phosphor was synthesized via solid state reaction method using strontium carbonate SrCO3 and cerium oxide CeO2 as raw materials. The samples were characterized by Thermo analytical techniques (TG, DTA, DTG and DSC) in nitrogen atmosphere, Fourier transformation infrared (FTIR) spectroscopy, and Photoluminescence at room temperature. Thermal analysis indicates that Sr2CeO4 phosphor can be prepared at temperature higher than 1100 °C. In excitation spectra two excitation peaks were located at 262 and 399 nm respectively. The emission spectrum was a broad band peaking at 470 nm, which was suitable for the doping of rare earth ions. The color co-ordinates for the pure Sr2CeO4 were x = 0.1918 and y = 0.2483. This material has potential for applications in the field of emission devices.

Swift Heavy Ion Irradiation Induced Structural, Optical And Conformational Modifications In Conducting Polymer Nanostructures

A. Kumar;Somik Banerjee

Advanced Materials Letters, 2013, Volume 4, Issue 6, Pages 433-437
DOI: 10.5185/amlett.2012.ib.109

Structural and conformational modifications in conducting polymer nanostructures viz., Polyaniline (PAni) nanofibers induced by swift heavy ion (SHI) irradiation have been investigated employing TEM, XRD, UV-Vis, FTIR and micro-Raman spectroscopy. Upon interaction with the highly energetic ions, PAni nanofibers are fragmented and get amorphized. The local range of order is found to decrease with a corresponding increase in the concentration of point defects and dislocations leading to the enhancement in strain. Vibrational spectra of the pristine and SHI irradiated PAni nanofibers studied using FTIR and micro-Raman (μR) spectroscopy indicate conformational changes in PAni nanofibers upon SHI irradiation. Loss of π-stacking due to the enhancement in the torsion angle between Cring-N-Cring upon irradiation is indicative of strong electrostatic interaction between the electron rich C-N site in the aromatic rings of PAni chains and the ion beam. The most significant variation in PAni nanofibers upon SHI irradiation is the transformation of para di-substituted benzene (benzenoid) structure of PAni into the quinone di-imine (quinoid) structures; a phenomenon that has been simultaneously observed in both the FTIR and Raman spectra. The presence of two main peaks representing the same structures in PAni nanofibers in both the Raman and IR spectra is because of the presence of delocalized sp2 phases and local disorder in PAni nanofibers, which gives rise to electrical and mechanical fluctuations that destroy the symmetry rules.

Microwave Synthesis And Characterization Of Nanocrystalline Mn-Zn Ferrites

Surender Kumar; Tukaram J. Shinde; Pramod N. Vasambekar

Advanced Materials Letters, 2013, Volume 4, Issue 5, Pages 373-377
DOI: 10.5185/amlett.2012.10429

Powder diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy were used to characterize the spinel structure of nanocrystalline Ferrites with composition Mn1-xZnxFe2O4 (x = 0.2, 0.4, 0.6 and 0.8) prepared by oxalate coprecipitation technique and followed by microwave heating of precursors. Effect of composition on the lattice constant, x-ray density, crystallite size was studied. Crystallite size and x-ray density increases with increase in Zinc content. The face centered cubic spinel structure has undergone deviation from ideality. A correlation exists between splitting of infrared absorption bands and lowering of composition dependent crystalline symmetry. This preparation technique could be used for synthesis of materials which use microwave transparent precursors.

Neodymia-silica Nanocomposites: Sythesis and Structural Properties

Saruchi Surbhi; Praveen Aghamkar; Sushil Kumar

Advanced Materials Letters, 2013, Volume 4, Issue 1, Pages 78-81
DOI: 10.5185/amlett.2013.icnano.109

Nanomaterials and nanostructures have received steadily growing interests as a result of their peculiar and fascinating properties and applications. Neodymia-silica nanocomposites were prepared by sol-gel route followed by calcination. The samples were prepared with different concentration of dopant (Nd2O3) and calcined in a programmable furnace at 1000 °C for 5 h. The structural evolution of samples was investigated by employing techniques such as XRD, FTIR and TEM. X-ray diffraction patterns showed that the samples were nanocrystalline and the size of crystallites has been determined using Debye-Scherrer relation. The FTIR spectra confirmed the presence of functional groups of prepared material. The particle size of samples was also estimated through TEM analysis. It has been observed that crystallinity as well as particle size of the samples increases with increase in dopant concentration.

Structural, Magnetic And Optical Studies Of nickel Ferrite Thin Films

Gagan Dixit; J.P. Singh; R.C. Srivastava; H.M. Agrawal; R.J. Chaudhary

Advanced Materials Letters, 2012, Volume 3, Issue 1, Pages 21-28
DOI: 10.5185/amlett.2011.6280

In the present work, structural, morphological, magnetic and optical properties of nickel ferrite thin films having different thickness are reported. All the films were deposited on Si (100) substrate by pulsed laser deposition technique. Thicknesses of the films determined by x-ray reflectivity vary from 62 to 176nm as the deposition time varies from 16 min to 40 min. The films were characterised by x-ray diffractogram, Fourier transform infrared (FTIR) and Raman spectroscopy for structural and phase confirmation. FTIR and Raman spectra confirm mixed spinel nature of nickel ferrite. Surface morphology is studied by Atomic force microscopy. All the films have granular nature. Magnetic properties were studied by vibrating sample magnetometer and magnetic hysteresis curves were recorded for all the films at room temperature and at10K. At 10K, saturation magnetisation was found to increase while coercivity deceases with thickness. The results are explained on the basis of anisotropy induced by cation inversion and strain. Optical properties were studied by UV-vis reflectance spectra. The value of optical band gap (5.7eV) was found to be independent of thickness of the film.

Photoluminescence studies of trichloro-DPQ organic phosphor

S.B. Raut; S.J. Dhoble; R.G. Atram

Advanced Materials Letters, 2011, Volume 2, Issue 5, Pages 373-376
DOI: 10.5185/amlett.2011.3075am2011

A new blue emitting material containing quinoline is designed, synthesized and characterized. The material has been prepared by well-known reaction such as Friedlander condensation reaction at 140 °C. The blended thin films of Trichloro-DPQ with poly (methyl methacrylate) (PMMA) at different weight % concentrations such as 10, 5, 1 and 0.1 weight % have been prepared. The structural characterization has been done by FTIR spectra. The synthesized polymeric compound demonstrates emission in blue region at 460 nm in powder form. At different weight % concentrations, there is emission at 444 nm with varying intensity. The light emitting and optoelectronic property of polymeric compound may find application in electroluminescence, OLED and sensors.

Structural, Optical And Gas Evolution Studies Of 60 MeV Si5+ Ion Irradiated PoT-PVC Blends

Advanced Materials Letters, 2011, Volume 2, Issue 2, Pages 125-130
DOI: 10.5185/amlett.2010.1214

Swift Heavy Ion (SHI) irradiation induces chemical and structural changes in polymers by evolving various gases and gaseous fragments. The evolution of gases as a result of chain scissoring and bond breaking leads to cross-linking and cluster formation. Study of the evolved gases helps in understanding the various chemical and structural changes occurring within the polymer under the effect of SHI irradiation. In the present work, Poly (o-toluidine) (PoT), a derivative of polyaniline, is prepared by chemical oxidation polymerization and is blended with polyvinylchloride (PVC) to achieve self supported films. These PoT-PVC blend films were irradiated by 60 MeV Si 5+ ions at different fluences and evolved gases were monitored on-line by Residual Gas Analyzer (RGA). Pre and post irradiation FTIR, UV-Visible absorption and XRD studies have been carried out on these films to observe the changes in chemical/structural and optical properties. An effort has been made to correlate the evolved gases and structural properties after irradiation.Copyright © 2011 VBRI press.