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| 1 | Structural and photoluminescence studies of Eu^(3+) doped zinc oxide nanorods prepared by precipitation method显示文摘Trivalent europium doped zinc oxide (ZnO:Eu3+) nanocrystals were synthesized via room temperature chemical co-precipitation and they were systematically characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and photoluminescence (PL) spectroscopy. The as-synthesized samples were found to have hexagonal wurtzite coexisted with the intermediate Zn5(OH)8Cl2·H2O phase, while the single hexagonal phase was facilitated due to the calcinations. The as obtained samples were broadly composed of nanoflakes while the highly crystalline nanorods were formed due to low temperature annealing of the as-synthesized samples. The crystallite size of the nanoflakes and nanorods (40-90 nm) were extracted from the XRD pattern which was found to be consistent with scanning electron microscopy (SEM) measurements. The photolumi-nescence (PL) spectra of nanophosphors showed bright red and orange emissions at 618 and 594 nm respectively with efficient broad blue green emission spectrum due to ZnO lattice. Further, a good energy transfer process from ZnO host to Eu3+ was observed in PL emission and excitation spectra of Eu3+ doped ZnO ions. In all, the present nanophosphors were found to have great potentiality for bio-applications. | Partha P.Pal J.Manam | 2013 | Journal of Rare Earths2013，31，1： | 8 |
| 2 | Supercontinuum generation in a Bragg fiber:a novel proposal显示文摘We propose a silica-core dispersion-decreasing Bragg fiber (DDBF) of mode effective area as large as 55 μm2 for supercontinuum (SC) generation at the pump wavelength of 1 060 nm.Using a fast and simple matrix method to model propagation in the DDBF,we have presented a general criterion to obtain the shortest length of the DDBF that would result in a broad SC spectrum.The proposed DDBF design should be amenable for reproducible fabrication through the well-developed MCVD fiber manufacturing technology and the concept has potential for realization as a practical device. | Bishnu P.Pal Sonali Dasgupta M.R.Shenoy Alexej Sysoliatin | 2006 | Optoelectronics Letters2006，2，5： | 1 |
| 3 | Ply-by-Ply Failure Analysis of Laminates under Dynamic Loading显示文摘Ply-by-ply failure analysis of symmetric and anti-symmetric laminates under uniform sinusoidal transverse dynamic loading is performed for a specified duration.The study investigates the first ply failure load,followed by the detection of successive ply failures and their failure modes using various failure theories.Some of the well-established failure theories,mostly used by the researchers,are considered for the failure prediction in laminates.The finite element computational model based on higher order shear deformation displacement field is used for the failure analysis and the complete methodology is computer coded using FORTRAN.The ply-discount stiffness reduction scheme is employed to modify the material properties of the failed lamina.The failure theories used in the analysis are compared according to their ability to predict failure load,failed ply,failure mode and progression of failure.The failure analysis is performed for both the cross-ply and angle-ply laminates with all edges simply supported and clamped.The significance of fibre orientation and stacking sequence in terms of the strength of a laminate and failure progression is also highlighted. | Ravi Joshi P.Pal | 2021 | Sound & Vibration2021，55，2： | 0 |
| 4 | ZnO_(1-x)Te_x and ZnO_(1-x)S_x semiconductor alloys as competent materials for opto-electronic and solar cell applications:a comparative analysis显示文摘ZnO_(1-x)Te_x ternary alloys have great potential to work as a photovoltaic(PV) absorber in solar cells.ZnO_(1-x)S_x is also a ZnO based alloy that have uses in solar cells.In this paper we report the comparative study of various parameters of ZnO_(1-x)Te_x and ZnO_(1-x)S_x for selecting it to be a competent material for solar cell applications.The parameters are mainly being calculated using the well-known VCA(virtual crystal approximation) and VBAC(Valence Band Anti-Crossing) model.It was certainly being analysed that the incorporation of Te atoms produces a high band gap lower than S atoms in the host ZnO material.The spin-orbit splitting energy value of ZnO_(1-x)Te_x was found to be higher than that of ZnO_(1-x)S_x.Beside this,the strain effects are also higher in ZnO_(1-x)Te_x than ZnO_(1-x)S_x.The remarkable notifying result which the paper is reporting is that at a higher percentage of Te atoms in ZnO_(1-x)Te_x,the spin-orbit splitting energy value rises above the band gap value,which signifies a very less internal carrier recombination that decreases the leakage current and increases the efficiency of the solar cell.Moreover,it also covers a wide wavelength range compared to ZnO_(1-x)S_x. | Utsa Das Partha P.Pal | 2017 | Journal of Semiconductors2017，38，8： | 0 |
| 5 | Effect of Co substitution on the structural,dielectric and optical properties of KBiFe_(2)O_(5)显示文摘Cobalt(Co)-modified brownmillerite KBiFe_(2)O_(5)(KBFO;[KBiFe_(2(1−x))Co_(2x)O_(5)(x=0,0.05)])polycrystalline is synthesized following the solid-state reaction route.Rietveld refinement of X-ray diffraction data confirmed the phase purity of KBFO and KBiFe_(1.9)Co_(0.1)O_(5)(KBFCO).The optical bandgap energy(Eg)of KBFO decreased from 1.59 to 1.51 eV because of Co substitution.The decrease in bandgap can be attributed to the tilting of the Fe–O tetrahedral structure of KBFCO.The observed room-temperature Raman peaks of KBFCO shifted by 3 cm^(−1) toward a lower wavenumber than that of KBFO.The shift in Raman active modes can be attributed to the change in the bond angles and bond lengths of the Fe–O tetrahedral structure and modification in response to oxygen deficiency in KBFO because of Co doping.Compared with that of KBFO,the frequency-dependent dielectric constant and dielectric loss of KBFCO decrease at room temperature,which is a consequence of the reduction in oxygen migration and modification in response to vibrational modes present in the sample. | K.Chandrakanta R.Jena P.Pal Md.F.Abdullah S.D.Kaushik A.K.Singh | 2021 | International Journal of Minerals,Metallurgy and Materials2021，28，11： | 0 |
| 6 | Dielectric relaxation and conduction mechanism in Aurivillius ceramic Bi_(5)Ti_(3)FeO_(15)显示文摘For this study,we synthesized Aurivillius Bi_(5)Ti_(3)FeO_(15) ceramic using the generic solid-state reaction route and then performed roomtemperature X-ray diffraction to confirm that the compound had a single phase with no impurities.The surface morphology of the prepared sample was observed to contain microstructural grains approximately 0.2–2μm in size.The dielectric properties of the sample were determined as a function of frequency in a range of approximately 100 Hz to 1 MHz at various temperatures(303 K≤T≤773 K).Nyquist plots of the impedance data were found to exhibit a semi-circular arc in the high-temperature region,which is explained by the equivalent electrical circuit(R_(1)C_(1))(R_(2)QC_(2)),where R_(1) and R_(2) represent the resistances associated with the grains and grain boundaries,respectively,C_(1) and C_(2) are the respective capacitances,and Q is the constant phase element(CPE),which accounts for non-Debye type of behavior.Our results indicate that both the resistance and capacitance of the grain boundaries are more prominent than those of the grains.The alternating current(ac)conductivity data were analyzed based on the Jonscher universal power law,which indicated that the conduction process is dominated by the hopping mechanism.The calculated activation energies of the relaxation and conduction processes were very similar(0.32 to 0.53 eV),from which we conclude that the same type of charge carriers are involved in both processes. | Rasmita Jena K.Chandrakanta P.Pal Md.F.Abdullah S.D.Kaushik A.K.Singh | 2021 | International Journal of Minerals,Metallurgy and Materials2021，28，6： | 0 |
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