Volume 6, Issue 10, October 2015


International Conference On Materials Science & Technology (ICMTech - 2016), India  

Ashutosh Tiwari

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 847-847
DOI: 10.5185/amlett.2015.10001

VBRI Press is pleased to announce Conference on Materials Science & Technology (ICMTech) during 01 – 04 March 2016, India. It is a four-day international event organised with collaboration of International Association of Advanced Materials (IAAM), and University of Delhi at the Conference Centre, University of Delhi, India. The goal of conference is to provide a global platform for high-tech materials and their manufacturing activities in India. The researchers and engineers coming from academia and industries will be interacted for the advancements of this sector through step towards The conference will provide opportunities for the delegates to exchange their face-to-face novel ideas and experiences with the international experts during the plenary and invited talks, oral presentations and poster sessions. We will also set up two parallel symposiums on Smart Energy Technologies and Large Scale High-tech Materials with keynote forum, panel discussion and manufacturing projects negotiation in India.

Preparation Of Epoxy Graphene And Its Structural And Optical Properties

Srinivasarao Yaragalla; Gopinathan Anilkumar; Vineeshkumar T. V.; Nandakumar Kalarikkal; Sabu Thomas

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 848-852
DOI: 10.5185/amlett.2015.5914

Epoxy graphene (EG) was synthesized from graphite (GT) powder using meta chloroperbenzoic acid (mCPBA) as an oxidizing agent at room temperature. Structural properties of the prepared EG were investigated by Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy and UV-visible spectroscopy. Results of FT-IR and Raman spectroscopy confirmed that the epoxy groups are incorporated into graphene basal planes. The layered structure of EG was determined using transmission electron microscope (TEM). Optical properties of the prepared EG were analyzed using UV-visible spectroscopy and Photo luminescence (PL) spectroscopy. From the UV-visible spectroscopy data, the band gap of EG was found to be 4.1 eV and this energy gap was roughly correlated with the maximum photoemission behavior of EG and the fluorescence energy was found to be dependent on the excited wavelength. These novel functional materials could be used for applications in the field of opto-electronic and light emitting devices.

Structural, Dielectric, Magnetic And Magnetoelectric Characterization Of Co0.5Ni0.5Fe2O4 - Bi0.9La0.1FeO3 Composite

Manjusha and K. L. Yadav; Manjusha;K. L. Yadav

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 853-861
DOI: 10.5185/amlett.2015.5856

Mixed spinel -perovskite composites of (x) Co0.5Ni0.5Fe2O4-(1−x) Bi0.9La0.1FeO3(x = 0, 0.25, 0.40, 0.55, 1.0) have been synthesized by conventional solid state reaction method and annealed at 850 ºC. The X-ray diffraction (XRD) pattern shows that the composites consisted of spinel Co0.5Ni0.5Fe2O4 and rhombohedral perovskite Bi0.9La0.1FeO3 ceramics. FESEM micrographs show closely packed microstructure with grain size in the range 503 nm - 960 nm. Variation of dielectric constant and dielectric loss with temperature at two fixed frequencies (500 kHz and 1 MHz) was studied. The composite with composition x = 0.55/sintered at 850 ºC exhibits the largest coercitivity (Hc) of 883 Oe. The saturation magnetization (Ms) and magnetic moment (µB) increase with an increase of Co0.5Ni0.5Fe2O4 concentration in the composites. From ferroelectric hysteresis loop analysis the values of remnant polarization (Pr) and coercive field (Ec) was found to lie in the range of 0.018-0.745 µC/cm 2 and 3.89-6.06 kV/cm. The relative change of magnetocapacitance was found to be 6.6% at a magnetic field of 8 kOe for x = 0.55 composition. Impedance analysis suggests the presence of a temperature dependent electrical relaxation in the material having a typical negative temperature coefficient of the resistance (NTCR) behavior analogous to a semiconductor.

Growth And Field Emission Properties Of Vertically-aligned ZnO Nanowire Array On Biaxially Textured Ni-W Substrate By Thermal Evaporation

Deepak Chhikara; K. M. K. Srivatsa; M. Senthil Kumar; Preetam Singh; Sourav Das; O. S. Panwar

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 862-866
DOI: 10.5185/amlett.2015.5886

Vertically well aligned and highly dense ZnO nanowires (NWs) have been grown on biaxially textured Ni substrates by a simple thermal evaporation technique over a large area without using any catalyst. The grown ZnO NWs have crystallized in wurtzite hexagonal structure and have grown along [0001] direction. It is also observed that the degree of vertical alignment of NWs increases with increasing growth temperature. An intense photoluminescence peak at 383 nm with a negligible deep band emission revealed the good crystalline quality of ZnO NWs. Field emission properties of the grown NWs have been examined and a field enhancement factor of 1573 has been obtained, indicating the suitability of grown nanowires for field emission applications.

Aqueous Phase Photodegradation Of Rhodamine B And P-nitrophenol Desctruction Using Titania Based Nanocomposites

Suranjan Sikdar; Sayantan Pathak; Tanmay K Ghorai

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 867-873
DOI: 10.5185/amlett.2015.5858

Heterogeneous photocatalysts offer great potential for converting photon energy into chemical energy for decomposition and destruction of organic contaminants from organic molecules i.e. Rhodamine B (RhB) and p-nitophenol (p-NP) under UV light. The titania based novel MxNbxTi1-2xO2-x/2 (M = Cr, Fe; x = 0.01-0.2) was prepared by tetra and tri-podal amine type binder with iron or chromium support using sol–gel method followed by calcination at 150 o C in an auto generated pressure. The photodegradation performance of the optimized catalyst was compared with synthesized nano-compositions, P-25 titania with RhB and p-NP. The particle sizes, surface area, mesopore sizes of CrxNbxTi1-2xO2-x/2 (x = 0.01) (CNT1) and FexNbxTi1-2xO2-x/2 (x = 0.01) (FNT1) are 12±1 and 10±2 nm, SBET=162 and 145 m 2 g −1 , 4.9 and 4-5 nm, respectively. The energy band gap of CNT1, FNT1 and NT was found to be 1.85, 2.06 and 2.1 eV, respectively. The importance of CNT1 powders is that it shows good photocatalytic activity for the degradation of Rhodamine B (RhB) within only 180 min and the importance of FNT1 powders is that it reduces the p-NP to p-aminophenol using a little bit of NaBH4 (0.054 g) within 10 min as compared to pure anatase TiO2 and other compositions of MxNbxTi1-2xO2-x/2 (M = Cr, Fe).

Silver Ion Conducting Characteristics Of A Polyethylene Oxide-based Composite Polymer Electrolyte And Application In Solid State Batteries

S. Amudha; S. Austin Suthanthiraraj

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 874-882
DOI: 10.5185/amlett.2015.5831

The matrix embracing a combination of polyethylene oxide [PEO] as the host polymer component and silver trifluoromethane sulfonate [AgCF3SO3] (also known as silver triflate) as the dopant salt yielding a composite polymer electrolyte [CPE] with varying compositions based on rich contents of Oxygen/Metal [O/M] ratio has been prepared in the form of thin film specimens using solution casting technique and examined for its application in a solid state battery configuration as a test cell. Such composite polymeric films optimized using electrical conductivity studies have provided realization of a maximum electrical conductivity value of 2.9 ×10 -5 Scm -1 at room temperature (298 K) whereas their temperature-dependent electrical conductivity is found to obey the Arrhenius behavior. Silver ionic transference number (tAg + ) data for these polymeric composites were indomitable using ac/dc polarization technique whereas the occurrence of a transition of phase in accordance with structural and thermal parameters could be investigated by means of X-ray diffraction (XRD) and differential scanning calorimetric (DSC) analyses. The morphological and compositional analyses were carried out by employing scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDX) as analytical tools. Electrochemical cells have been fabricated with the common cell configuration Ag|CPE|(I2+G+CPE) and relevant cell parameters evaluated in terms of their discharge characteristics under a constant load of 1 M at room temperature.

Single Oriented CeO2 Buffer Layer Deposition On Biaxially Textured Ni-W Substrate By RF Magnetron Sputtering

K.M.K. Srivatsa; Preetam Singh; Sourav Das

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 883-887
DOI: 10.5185/amlett.2015.5884

Considerable attention has been gained on the deposition of CeO2 thin films with (200) single orientation as hetero-epitaxial buffer layer on (200) oriented biaxially textured flexible Ni substrates, in the fabrication of superconductor and semiconducting epitaxial thin films for device applications. In this work we have deposited (200) oriented CeO2 thin films on biaxially textured Ni-W substrate in a single-step process by RF magnetron sputtering, using CeO2 target. X-ray diffraction analysis shows that for the CeO2 thin film deposited at RF sputtering power below 200 W and for the substrate temperature of 700 o C, the film assumes single (200) orientation. For the substrate temperature below 700 o C and RF sputtering powers above 200 W the film shows polycrystalline nature with (111) and (200) orientations. The Raman spectrum of single oriented (200) CeO2 thin film shows only one sharp peak at about 464 cm -1 corresponds to the presence of F2g mode of CeO2. The ellipsometry studies reveal the value refractive index and optical band gap of single oriented film as 2.52 and 3.41 eV, respectively.

An Experimental And Numerical Investigation Of Tensile Properties Of Stone Wool Fiber Reinforced Polymer Composites

S.T. Leong; Y. Yusof; C.F. Tan

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 888-894
DOI: 10.5185/amlett.2015.5835

The present work focuses on determination of tensile properties of stone wool fiber reinforced high density polyethylene composites by two methods: experimental and finite element analysis. Four weight percentage of stone wool (SW) fiber 10 – 40 wt. % were chosen. The samples of composites were made by using the hot press technique. ASTM D638 was used to test the composite samples. Scanning electron microscopy analysis was carried out on the fractured surface to observe the interaction between matrix and fiber in the composites. Significant improvement of tensile properties was observed and recorded from the composites with SW weight percentage of 20 wt. %. The yield strength, tensile strength and tensile modulus increased by 8.1%, 23.0% and 37.8% over pure HDPE. ANSYS tensile models were then established to understand better the processing and behavior phenomenon. The numerical results obtained were in good agreement with the experimental results, with an accuracy of more than 90%.

Investigations On Multiferroic, Optical And Photocatalytic Properties Of Lanthanum Doped Bismuth Ferrite Nanoparticles

Manpreet Kaur; K. L. Yadav; Poonam Uniyal

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 895-901
DOI: 10.5185/amlett.2015.5861

Single phase Bi1-xLaxFeO3 nanoparticles have been successfully synthesized with varied concentration (0.0 ≤ x ≤ 0.2) for the photocatalytic degradation of an industrial dye. The room temperature X-ray diffraction (XRD) pattern of La 3+ doped BiFeO3 nanoparticles reveals the structural phase transition from rhombohedral (R3c) to orthorhombic (Pnma) at x=0.1, which is further analyzed via Rietveld refinement. The La 3+ doped BiFeO3 nanoparticles have much negative enthalpy of formation (ΔHf) than undoped BiFeO3. The particle size gradually decreases from ~132 to ~68 nm with La 3+ doping. Magnetic and ferroelectric transition temperatures are found to be slightly shifted towards room temperature upto x= 0.1 and then higher temperature side which could be attribute to the particle size effect. All compositions presented weak ferromagnetic ordering, which indicates that the La 3+ substitution in the BiFeO3 matrix released the latent magnetization. The increase in the energy band gap from 2.045 to 2.658 eV with cutoff wavelengths 639.58 and 513.061 nm for x=0.0 and 0.2 respectively, increases the visible light efficiency of photocatalytic activity in La 3+ doped BiFeO3 samples. The photodegradation efficiency of La 3+ doped BiFeO3 for azo-dye RB-5 is observed to be ~27% higher as compared to the undoped BiFeO3 (43% photodegradation efficiency), which makes it suitable for visible-light responsive photocatalysis for photocatalytic applications.

Effect Of Nickel Ferrite On Bismuth Ferrite To Generate Nanocomposite In Relation To Structure, Characterization, Magnetic Properties And Band Gap Evaluation

Soumya Mukherjee; Manoj Kumar Mitra

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 902-906
DOI: 10.5185/amlett.2015.5833

Multiferroic materials are new class of multi-functional materials which possess both ferro-electric and magnetic properties. This type of material has wide range of applications like semi-conducting to sensors applications.  Nanocomposite of equimolar perovskite-spinel is synthesized by chemical route by blending of Nickel ferrite as second phase on Bismuth ferrite after heat treatment at 500 °C for 2, 3 and 4 hours soaking period. From the diffractogram data of XRD, the phase, and planes of orientation are analyzed of the synthesized materials. The crystallite size is calculated by Scherrer’s formula. FESEM studies reveal the morphological features having interconnected agglomerates with spherical, irregular polygonal or some elongated shape of the synthesized nanocomposite. FTIR result shows the molecular signature of the nanocrystalline material to verify the M-O coordination. Interplanar spacings and SAED pattern are revealed from HRTEM images which are very close to the experimental findings from XRD phase analysis. UV-VIS analysis is performed in the transmission mode of spectra within the scan range of 200-1100 nm. From the spectra, using Tauc relation band gap is calculated. Band gap are found of the order of 2.847 eV, 2.78 eV, 2.69 eV respectively for 2, 3 and 4 hours soaking period close to semiconducting material. With the increase of soaking time band gap is found to decrease following Arrhenius activation of electronic mobility overwhelming the energy barrier at respective lattice sites. M-H analysis of Nanocomposite at 500 °C for 2 hrs is closer towards ferromagnetic with incomplete loop but for sample at 500 °C for 4hrs it is closer towards superparamagnetic one. The property of this material reflects it has many interesting characteristics suitable for opto-electronic, photo-magnetic devices and other electronic applications.

Preparation And Physical Characterization Of CdTe Thin Films Deposited By Vacuum Evaporation For Photovoltaic Applications

Subhash Chander; M. S. Dhaka

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 907-912
DOI: 10.5185/amlett.2015.5926

The present communication reports the preparation and physical characterization of CdTe thin films for photovoltaic application. The thin films of thickness 660 nm and 825 nm were deposited on glass and ITO coated glass substrates employing thermal vacuum evaporation deposition method. These as-deposited films were characterized using XRD, UV-Vis spectrophotometer, source meter, SEM and AFM for physical properties. The XRD patterns reveal that the films are crystallized zinc-blende structure of cubic phase with preferred orientation (111) as well as polycrystalline in nature. The optical and crystallographic parameters are calculated and widely discussed. The optical band gap is found in the range 1.52 - 1.94 eV and observed to decrease with thickness. The current-voltage characteristics show that the current is found to be decreased with thickness and the resistivity is increased. The SEM studies show that the films are homogeneous, uniform and free from crystal defects. The grains in the thin films are similar in size and densely packed. The AFM studies reveal that the surface roughness is observed to increase for higher thickness. The experimental results reveal that the films of thickness 825 nm may be used as absorber layer in CdTe/CdS thin film solar cells due to its optical band gap 1.52 eV which is almost identical with the optimum band gap of CdTe and good crystallinity.

Biophysical Study On The Interaction Of Spirooxindole-annulated Thiopyran Derivatives With Bovine Serum Albumin Using Spectroscopic And Docking Methods

Swarup Roy; Sudipta Ponra; Raj Kumar Nandi; K. C. Majumdar; Tapan Kumar Das

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 913-919
DOI: 10.5185/amlett.2015.5931

The study of interaction between spirooxindole-annulated thiopyran derivatives (STP) and bovine serum albumin (BSA) was investigated using multi-spectroscopic and docking method. The intrinsic fluorescence of BSA could effectively quenched by STP through dynamic quenching. The thermodynamic parameters suggested that hydrogen bonds and van der Waals forces played a key role in stabilizing the BSA–STP complexes. According to Forster non radiation energy transfer theory (FRET) the average binding distance (r) between STP and BSA were found to be < 7 nm. Furthermore, UV-visible and circular dichroism results indicated that in presence of STP secondary structure of BSA changed. Theoretical docking study of the interaction of BSA and STP also supported the experimental results.

Bulk-heterojunction Solar Cells With Different Active Layer Blends: Comparison Of Experimental And Theoretical Results

Vishal Sharma; Vinamrita Singh; Manoj Arora; Swati Arora; R.P. Tandon

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 920-923
DOI: 10.5185/amlett.2015.5981

Bulk-heterojunction (BHJ) organic solar cells (OSCs) were fabricated with various active layer materials. Solar cells of configuration ITO/PEDOT:PSS/P3HT:PC61BM/Al, ITO/PEDOT:PSS/P3HT:PC71BM/Al and ITO/PEDOT:PSS/ PCDTBT:PC71BM/Al were fabricated. Current density-voltage (J-V) characteristics were measured in the dark and under illumination in ambient conditions. A single theoretical model was able to explain the J-V characteristics of all freshly prepared cells using realistic parameters.

Thermal Evolution Of Structural, Optical And Photocatalytic Properties Of TiO2 Nanostructures

Jaspal Singh; Satyabrata Mohapatra

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 924-929
DOI: 10.5185/amlett.2015.6000

Nanostructures of TiO2 were synthesized by a facile sol-gel method using pentanol as solvent. The effects of thermal annealing on the structural, optical and photocatalytic properties of as-synthesized TiO2 nanostructures have been studied using X-ray diffraction (XRD), atomic force microscopy (AFM), Raman spectroscopy and UV-visible absorption spectroscopy. XRD and Raman spectroscopy results revealed that the synthesized TiO2 nanostructures exist in anatase phase for annealing at temperatures up to 300 o C, while annealing at 600 o C led to the formation of TiO2 nanostructures in anatase/rutile mixed-phase. AFM studies revealed the presence of TiO2 nanorods, which showed a small decrease in aspect ratio upon annealing. The photocatalytic activity of nanostructured TiO2 samples was evaluated through sun light driven degradation of methylene blue (MB) dye in water. TiO2 nanorods in anatase/rutile mixed-phase in the sample annealed at 600 o C were found to exhibit the highest photocatalytic activity towards degradation of MB dye. The mechanism underlying the enhanced photocatalytic activity of TiO2 nanostructures in anatase/rutile mixed-phase is tentatively proposed.

Correlation Between Oxygen Partial Pressure And Properties Of Pulsed Laser Deposited SnO2/Fe2O3 Composite Films

M. Chowdhury; S.K. Sharma; R.J. Chaudhary

Advanced Materials Letters, 2015, Volume 6, Issue 10, Pages 930-934
DOI: 10.5185/amlett.2015.6017

SnO2/Fe2O3 composite thin films were deposited on quartz substrates at various oxygen partial pressures with a substrate temperature of 750 °C by pulsed laser deposition. The structural and optical properties of the deposited films were studied by X-ray diffraction (XRD), Atomic force microscopy (AFM), UV–visible spectroscopy and Photoluminescence. X-ray diffraction analysis revealed the formation of mixed phases (tetragonal SnO2 and hexagonal α-Fe2O3) at lower oxygen partial pressure (0.1 mTorr) and only tetragonal phase at higher oxygen partial pressures (50-250 mTorr). Atomic force microscopy studies show the dense and uniform distribution of composite films. The average RMS roughness of the films increases with increasing oxygen partial pressure. The bandgap was found varying between 3.55 and 3.85 eV for different oxygen pressures. A strong broad blue emission band was observed for all the oxygen partial pressures. The origin of the blue emission in the composite film is discussed with the help of vacancy creation. A correlation between oxygen partial pressure and the properties of SnO2/Fe2O3 .