scholarly journals Dielectric and Optical Spectroscopy of New Poly-Crystalline Ceramic for device Applications

2021 ◽  
Author(s):  
Rajani K Parida ◽  
Sourav Bhattacharjee ◽  
Bhagyashree Mohanty ◽  
Nimai C Nayak ◽  
Bichitra Nanda Parida
Keyword(s):  
Perovskite Phase ◽  
Double Perovskite ◽  
Light Sensitivity ◽  
Spectroscopic Technique ◽  
Vibrational Modes ◽  
Average Grain Size ◽  
Device Applications ◽  
Crystalline Ceramic ◽  
Uv Visible ◽  
Lcr Meter

Abstract The polycrystalline double perovskite Li2GdFeTiO6 was synthesized through solid-state mixed oxide method and its preliminary crystal structure was investigated by XRD technique. The structure of the material was identified to be tetragonal with space group P4bm using POWD and MATCH software. The morphology of the sample was investigated through a scanning electron microscope (SEM) and the average grain size was found 3.82 µm using intercept technique. The investigation of the perovskite phase and various vibrational modes were carried out through FTIR spectroscopic technique. The band gap (Eg = 1.73 eV) and visible light sensitivity of the material were identified by UV-Visible spectroscopic operation carried in the range 200–700 nm. The dielectric and related properties were investigated as a function of frequency and temperature using an impedance analyzer (LCR meter). Room temperature dielectric investigation suggests it may be useful for storage application. The transport activities investigated through conductivity, impedance and modulus technique illustrate the significant influence of grains on transportation of charges.

pH Influences on Optical Absorption of Anthocyanin from Black Rice as Sensitizer for Dye Sensitized Solar Cell TiO2 Nanoparticles

2016 ◽  
Vol 864 ◽  
pp. 154-158
Author(s):  
Mariya Al Qibtiya ◽  
Eka Cahya Prima ◽  
Brian Yuliarto ◽  
Suyatman
Keyword(s):  
Solar Cell ◽  
Optical Absorption ◽  
Dye Sensitized Solar Cell ◽  
Black Rice ◽  
X Ray ◽  
Dye Sensitized ◽  
Current Voltage ◽  
Average Grain Size ◽  
Uv Visible

Natural dyes extracted from black rice are used as sensitizer for dye sensitized solar cell. The anthocyanin extracted with various pH in acidic and neutral coditions. Preparation of fotolectrode TiO2 film using doctor blade method and resulting average grain size 33,9 nm using X-Ray Diffractometer. Characterization of morphology and cross-section film TiO2 is confirmed by Scanning Electron microscopy (SEM). Optical absorption using UV-Visible Spectroscopy to obtain spectrum absorbance of anthocyanin in various pH. The current-voltage (J-V) characterization shows the performance DSSC have a match relation to the optical absorption. The best absorption of anthocyanin obtained at pH 6 as well as conversion efficiency reaches 2.26% at this pH condition.

Influence of Excess Bi2O3 and Na2Co3 on Crystal Structure and Microstructure of Bismuth Sodium Titanate Ceramics

2011 ◽  
Vol 474-476 ◽  
pp. 1711-1714 ◽  
Author(s):  
Panadda Sittiketkron ◽  
Arrak Klinbumrung ◽  
Theerachai Bongkarn
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Perovskite Phase ◽  
Average Particle Size ◽  
Sodium Titanate ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Rhombohedral Structure ◽  
Average Particle ◽  
Average Grain Size

This study investigated the influence of excess Bi2O3 and Na2CO3 on the crystal structure, microstructure and dielectric properties of (Bi0.5Na0.5)TiO3 (BNT) ceramics. The BNT ceramics were synthesized using the solid-state reaction method with various excess Bi2O3 and Na2CO3 levels (0, 1, 2, 3 and 4 mol%). The X-ray characterization revealed that all samples had a rhombohedral structure. A pure perovskite phase was obtained in all samples. The lattice parameter a tended to increase with increased excess Bi2O3 and Na2CO3 content in the calcined powders and sintered ceramics. The average particle size increased while, the average grain size tended to decreased with increased of excess Bi2O3 and Na2CO3 content. The depolarization temperature (Td) and the Curie temperature (Tc) were slightly decreased with the increase of excess Bi2O3 and Na2CO3 content. The dielectric properties were related to the density.

scholarly journals Effect of Re and Tm-site on morphology structure and optical band gap of ReTmO3 (Re: La, Ce, Nd, Gd, Dy, Y and Tm: Fe, Cr) prepared by sol-gel method

2018 ◽  
Vol 64 (4) ◽  
pp. 381
Author(s):  
Muhammad Tufiq Jamil ◽  
Javed Ahmad ◽  
Syed Hamad Bukhari ◽  
Murtaza Saleem
Keyword(s):  
Band Gap ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Orthorhombic Crystal ◽  
X Ray ◽  
Average Grain Size ◽  
Auto Combustion ◽  
Uv Visible

Rare earth nano sized pollycrystalline orthoferrites and orthocromites ReT mO3 (Re = La, Nd, Gd, Dy, Y and T m = Fe, Cr) have been synthesized by sol-gel auto combustion citrate method. The samples have been characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and UV-visible spectroscopy. The samples are single phase as confirmed by XRD analysis and correspond to the orthorhombic crystal symmetry with space group pbnm. Debye Scherer formula and Williamson Hall analysis have been used to calculate the average grain size which is consistent with that of determined from SEM analysis and varied between 25-75 nm. The elemental compositions of all samples have been checked by EDX analysis. Different crystallographic parameters are calculated with strong structural correlation among Re and Tm sites. The optical energy band gap has been calculated by using Tauc relation estimated to be in the range of 1.77 - 1.87 eV and 2.77 - 3.14 eV, for ReFeO3 and ReCrO3, respectively.

Synthesis and Electrical Conductivity of N-(3-(Trifluoromethyl)Benzylidine)Thiosemicarbazide towards Dyes Sensitized Solar Cell

2018 ◽  
Vol 382 ◽  
pp. 364-368
Author(s):  
Uwaisulqarni M. Osman ◽  
Azieda Syafika N. Farizal ◽  
Nurhayati Ishak ◽  
Mohd Hasmizam Razali ◽  
M.I.N. Isa
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Light Intensity ◽  
Indium Tin Oxide ◽  
Spectroscopic Technique ◽  
Ito Glass ◽  
Maximum Conductivity ◽  
Ft Ir ◽  
Uv Visible ◽  
Conductivity Of Thin Films

Organic compound containing thiosemicarbazide moiety has been successfully synthesized. The new synthesized dyes, N-(3-(Trifluoromethylbenzaldehyde)benzylidine thiosemi- carbazide (3-TFT) was characterized by spectroscopic technique namely, CHNS elemental analysis, Fourier Transform Infra-Red analysis (FT-IR), UV-Visible analysis (UV-Vis),1H and13C Nuclear Magnetic Resonance (NMR). The thin films of this dye have been prepared using a spin coating technique and deposited on indium tin oxide (ITO) glass substrate. The main highlight was an electrical conductivity of thin films which was measured using four point probing system in a range of light intensity, 25 Wm-2until 200Wm-2. The potential electrical conductivity of 3-TFT dye was found gradually increased until reached the maximum conductivity values of 0.1489 Scm-1at light intensity of 100 Wm-2in the most diluted concentration at 1x10-5M.

Structure and Electrical Properties of BNKT-Based Ceramics

2018 ◽  
Vol 283 ◽  
pp. 147-153 ◽  
Author(s):  
Supalak Manotham ◽  
Pichitchai Butnoi ◽  
Pharatree Jaita ◽  
Tawee Tunkasiri
Keyword(s):  
Grain Size ◽  
Perovskite Phase ◽  
Ferroelectric Properties ◽  
Tetragonal Symmetry ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Average Grain Size ◽  
Influence Of Temperature On ◽  
Polarization Electric Field ◽  
Xrd Patterns

In this work, the properties of lead-free 0.92(Bi0.5Na0.42K0.08)TiO3-0.08(BaNb0.01Ti0.99)O3 or 92BNKT-8BNbT ceramic has been investigated. The sample was fabricated by a solid-state reaction technique. The 92BNKT-8BNbT sample was well sintered and dense with high density value of 5.86 g/cm3. X-Ray diffraction (XRD) patterns showed a single perovskite phase with tetragonal symmetry and no impurity or secondary phases. The microstructure was analysed using a scanning electron microscopy (SEM). Average grain size was measured and calculated based on a mean linear intercept method. The ceramics had a cubic-like grain shape with an average grain size of 0.39 µm. The influence of temperature on the dielectric and ferroelectric properties of the ceramic was investigated. The dielectric curves exhibited broad transition peaks at Td and Tm, which were the characteristics of a diffuse phase transition. The polarization-electric field (P-E) hysteresis loop changed from well-saturated at room temperature (RT) to pinched-type loop at high temperature (HT) and the remanent polarization decreased from 21.25 µC/cm2 (at RT) to 5.96 µC/cm2 (at 150 °C).

scholarly journals Octahedral distortion-driven electrical and vibrational properties of A2ErTaO6 (A=Sr and Ca) double perovskite oxides

2018 ◽  
Vol 08 (04) ◽  
pp. 1850025
Author(s):  
Rajesh Mukherjee ◽  
Alo Dutta ◽  
T. P. Sinha
Keyword(s):  
Dielectric Constant ◽  
Perovskite Phase ◽  
Double Perovskite ◽  
Impedance Spectra ◽  
Phonon Modes ◽  
Solid State Route ◽  
Different Temperatures ◽  
Raman Modes ◽  
Conductivity Spectra ◽  
Octahedral Distortion

Rietveld refinement analysis indicates that [Formula: see text]ErTaO6 ([Formula: see text], Ca[Formula: see text] ceramics prepared by a solid-state route are crystallized in monoclinic perovskite phase with space group [Formula: see text]. Raman scattering and infrared spectroscopy are used to investigate the structure and phonon modes of the samples. Using Lorentzian lines, we have fitted the Raman spectra and the major Raman modes are assigned. Phonon vibrational frequency is modulated with the [Formula: see text]-site cationic change. Impedance spectra of the samples over the frequency range of 100[Formula: see text]Hz–1.1[Formula: see text]MHz are investigated at different temperatures from 303[Formula: see text]K to 573[Formula: see text]K. Cole–Cole relaxation of dielectric constant is modified with the electrical conduction parameter to describe the temperature dependence of dielectric constant. The frequency-dependent conductivity spectra follow the double power-law.

scholarly journals Deposition routes of Cs2AgBiBr6 double perovskites for photovoltaic applications

MRS Advances ◽  
2018 ◽  
Vol 3 (32) ◽  
pp. 1819-1823 ◽  
Author(s):  
Martina Pantaler ◽  
Christian Fettkenhauer ◽  
Hoang L. Nguyen ◽  
Irina Anusca ◽  
Doru C. Lupascu
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Perovskite Phase ◽  
Perovskite Solar Cells ◽  
Double Perovskite ◽  
Double Perovskites ◽  
Sequential Deposition ◽  
Absorber Material ◽  
Photovoltaic Applications ◽  
Deposition Processes

ABSTRACTThe lead free double perovskite Cs2AgBiBr6 is an upcoming alternative to lead based perovskites as absorber material in perovskite solar cells. So far, the majority of investigations on this interesting material have focused on polycrystalline powders and single crystals. We present vapor and solution based approaches for the preparation of Cs2AgBiBr6 thin films. Sequential vapor deposition processes starting from different precursors are shown and their weaknesses are discussed. Single source evaporation of Cs2AgBiBr6 and sequential deposition of Cs3Bi2Br9 and AgBr result in the formation of the double perovskite phase. Additionally, we show the possibility of the preparation of planar Cs2AgBiBr6 thin films by spin coating.

The Electrical Properties of BCZT Lead-Free Ceramics Induced by BaZrO3 Seeds

2016 ◽  
Vol 690 ◽  
pp. 114-119
Author(s):  
Piewpan Parjansri ◽  
Manlika Kamnoy ◽  
Uraiwan Intatha ◽  
Sukum Eitssayeam ◽  
Tawee Tunkasiri
Keyword(s):  
Grain Size ◽  
Electrical Properties ◽  
Perovskite Phase ◽  
Nano Particle ◽  
Sintered Ceramic ◽  
Voltage Coefficient ◽  
Lead Free Ceramics ◽  
Seed Content ◽  
Pure Perovskite Phase ◽  
Average Grain Size

Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) ceramics were produced by using the seed-induced method. The nano-particle BZ (BaZrO3) seeds were mixed with BaCO3, CaCO3, ZrO2 and TiO2 powder for preparing by the mixed oxide method. The XRD results indicated that all powder and sintered ceramic samples showed a pure perovskite phase with coexistence between rhombohedral and tetragonal phase. As the BZ seed content increased, the density of ceramics tended to decrease from 5.61 g/cm3 to 5.37 g/cm3. The average grain size of the ceramics was in the range of 12.15 -13.50 mm. The dielectric loss (tand) was less than 0.03 for all samples at room temperature (at 1 kHz). Other electrical properties, including dielectric constant (εr), remnant polarization (Pr), and piezoelectric charge coefficient (d33) values decreased with increasing BZ seed doping with relates to the decreasing grain size and density of BCZT ceramics. However, the values of coercive field (Ec) decreased and piezoelectric voltage coefficient (g33) increased with BZ seed doping.

scholarly journals Temperature characterization of dielectric permittivity and AC conductivity of nano copper oxide-doped polyaniline composite

2016 ◽  
Vol 06 (03) ◽  
pp. 1650018 ◽  
Author(s):  
L. N. Shubha ◽  
P. Madhusudana Rao
Keyword(s):  
Dielectric Permittivity ◽  
Copper Oxide ◽  
Ac Conductivity ◽  
Morphological Changes ◽  
Copper Oxide Nanoparticles ◽  
Sem Images ◽  
Increase With Increase ◽  
Visible Spectra ◽  
Uv Visible ◽  
Lcr Meter

The polyaniline/copper oxide (PANI/CuO) nanocomposite was prepared by mixing solutions of polyaniline and copper oxide nanoparticles in dimethyl sulfoxide (DMSO). The synthesized polymer nanocomposites were characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM) and UV–visible spectroscopy. The characteristic peaks in XRD and UV–visible spectra confirmed the presence of CuO in the polymer structure. SEM images indicated morphological changes in the composite matrix as compared to the pristine PANI. The DC conductivity measurements were performed using two-probe method for various temperatures. AC conductivity and dielectric response of the composites were investigated in the frequency range of [Formula: see text]–[Formula: see text][Formula: see text]Hz using LCR meter. Dielectric permittivity [Formula: see text] and dielectric loss factor [Formula: see text] were investigated. It was observed that [Formula: see text] and [Formula: see text] decrease with increase in frequency at all temperatures. At a particular frequency it is observed that both [Formula: see text] and [Formula: see text] increase with increase in temperature. It was also observed that AC conductivity increased with increase in frequency and temperature.

Effects of Surface Disordering on Optical & Mechanical Properties of Ar+ Implanted Polycarbonate

2012 ◽  
Vol 585 ◽  
pp. 537-541 ◽  
Author(s):  
Nidhi Shekhawat ◽  
Sanjeev Aggarwal ◽  
Annu Sharma ◽  
Krishan Gopal Murli Nair
Keyword(s):  
Structural Changes ◽  
Urbach Energy ◽  
Energy Gap ◽  
Dose Range ◽  
Spectroscopic Technique ◽  
Optical Energy Gap ◽  
Optical Energy ◽  
Energy Disorder ◽  
Uv Visible ◽  
Disorder Parameter

The surface disordering produced in polycarbonate specimens by 130 keV Ar+ ions has been investigated. The effect of argon ions on the surface structure of polycarbonate specimens has also been studied. The polycarbonate specimens were implanted with 130 keV Ar+ ions in the dose range of 1×1014-1×1016 ions cm-2. The change in the Urbach energy (disorder parameter) after implantation has been estimated using Urbach edge method by applying UV-Visible spectroscopic technique. Optical energy gaps of virgin as well as implanted specimens have also been calculated using UV-Visible spectroscopic technique. A clear enhancement in Urbach energy (disorder parameter) from 0.61 eV (virgin sample) to 1.38 eV (at a fluence of 1×1016 Ar+ cm-2) and a drastic decline in optical energy gap (4.1 eV to 0.63 eV) with increasing implantation dose has been observed. This decrease in optical energy gap has been found to have linear dependence on the increase in the Urbach energy which point towards the formation of disordered structures in the implanted layers of polycarbonate. The structural changes produced due to implantation have been studied using Attenuated Total Reflectance-Fourier Transform Infrared spectroscopic technique. Furthermore, Knoop microhardness has been found to be enhanced 14 times (at a load of 9.8 mN) after implantation. The possible correlation of the increase in Knoop surface hardness with the structural changes observed as a result of implantation has been established and discussed.

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