Lattice Dynamics and Transport Properties of Multiferroic DyMn2O5

We have investigated the optical and electrical properties of polycrystalline DyMn2O5synthesized by sol-gel method. Analysis of the reflectivity spectrum has led to the observation of 18 infrared (IR) active phonon modes out of 36 predicted ones. We discuss the results in terms of different phonon bands originated as a result of atomic vibrations. Moreover, the optical energy band gap ofEg(OC)~1.78 eV has been estimated from optical conductivity(σ1(ω))spectrum. The energy band gap and optical transitions were also determined from UV-visible absorption spectrum and band gap ofEg(UV)~1.57 eV was estimated. Moreover, DC electrical resistivity shows the p-type polaronic conduction above room temperature.

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Optical phonons and its effect on physical properties of rare-earth orthoferrites RFeO3 (R = La, Nd, Gd, Dy, Er): IR reflectivity measurements

International Journal of Modern Physics B ◽

10.1142/s0217979218502296 ◽

2018 ◽

Vol 32 (21) ◽

pp. 1850229

Author(s):

Muhammad Tufiq Jamil ◽

Javed Ahmad ◽

Syed Hamad Bukhari ◽

Hammad Ahmad

Keyword(s):

Sol Gel ◽

Structural Evolution ◽

Electrical Measurements ◽

Phonon Modes ◽

Lorentz Oscillator ◽

Reflectivity Spectra ◽

Visible Spectra ◽

Atomic Vibrations ◽

Uv Visible ◽

Method Analysis

We have investigated the infrared reflectivity, UV-visible spectra and electrical property of polycrystalline RFeO3 (R = La, Nd, Gd, Dy, Er) synthesized by sol–gel method. Analysis of IR reflectivity spectra through Lorentz oscillator model has led to the observation of 14 IR active phonon modes out of 25 predicted modes. The results have been discussed in terms of different phonon bands related to the origin of atomic vibrations, which provides information about the structural evolution. The energy bandgap [Formula: see text]1.67–1.90 eV estimated from optical conductivity ([Formula: see text]([Formula: see text])) spectrum is found consistent both with that calculated from UV-visible spectra and estimated from electrical measurements.

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Optoelectronics applications of electrodeposited p- and n-type Al2Se3 thin films

Materials Science-Poland ◽

10.2478/msp-2021-0011 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

A. A. Faremi ◽

S. S. Oluyamo ◽

O. Olubosede ◽

I. O. Olusola ◽

M. A. Adekoya ◽

...

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Band Gap ◽

Energy Band ◽

Selenium Dioxide ◽

Photoelectrochemical Cells ◽

Energy Band Gap ◽

Cathodic Deposition ◽

Conductivity Type ◽

P Type

Abstract In this paper, energy band gaps and electrical conductivity based on aluminum selenide (Al2Se3) thin films are synthesized electrochemically using cathodic deposition technique, with graphite and carbon as cathode and anode, respectively. Synthesis is done at 353 K from an aqueous solution of analytical grade selenium dioxide (SeO2), and aluminum chloride (AlCl2·7H2O). Junctions-based Al2Se3 thin films from a controlled medium of pH 2.0 are deposited on fluorine-doped tin oxide (FTO) substrate using potential voltages varying from 1,000 mV to 1,400 mV and 3 minutes −15 minutes respectively. The films were characterized for optical properties and electrical conductivity using UV-vis and photoelectrochemical cells (PEC) spectroscopy. The PEC reveals a transition in the conduction of the films from p-type to n-type as the potential voltage varies. The energy band gap reduces from 3.2 eV to 2.9 eV with an increase in voltage and 3.3 eV to 2.7 eV with increase in time. These variations indicate successful fabrication of junction-based Al2Se3 thin films with noticeable transition in the conductivity type and energy band gap of the materials. Consequently, the fabricated Al2Se3 can find useful applications in optoelectronic devices.

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The Role of Samarium Ion in Optical Properties of Magnesium Tellurite Glass Embedded with Silver Nanoparticles

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1107.460 ◽

2015 ◽

Vol 1107 ◽

pp. 460-465

Author(s):

M.Y. Nurulhuda ◽

M.R. Sahar

Keyword(s):

Band Gap ◽

Energy Band ◽

Tellurite Glass ◽

Urbach Energy ◽

Energy Band Gap ◽

Optical Energy ◽

Optical Energy Band Gap ◽

Absorption Studies ◽

Uv Visible

A series of tellurite glass based on composition (89.6-x)TeO2-10MgO-xSm2O3-0.4AgCl where 0.2x1.0 have successfully been prepared by melt-quenching technique. The optical behaviour has been examined as a function of Sm2O3 content by using UV-Visible Spectroscopy in the range of 200-900 nm. The absorption studies revealed that the indirect and direct optical energy band gap is in the range of 2.81-3.11 eV and 3.16-3.45 eV, respectively. Meanwhile, Urbach energy, E is in between 0.18-0.24 eV. The increasing in samarium ion up to 0.4 mol% of Sm2O3 result in an increment of optical energy band gap, but gradually decreases beyond 0.4 mol%. All the results will be discussed with respect to Sm2O3 content.

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Study and Characterization of Polystyrene/Titanium Dioxide Nanocomposites (PS/TiO2 NCs) for Photocatalytic Degradation Application: a Review

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i4.30.28172 ◽

2018 ◽

Vol 7 (4.30) ◽

pp. 538 ◽

Cited By ~ 1

Author(s):

Maytham Qabel Hamzah ◽

Salim Oudah Mezan ◽

Alaa Nihad Tuama ◽

Abdullah Hasan Jabbar ◽

Mohd Arif Agam

Keyword(s):

Laser Radiation ◽

Photocatalytic Degradation ◽

Band Gap ◽

Energy Band ◽

Sol Gel ◽

Dip Coating ◽

Sem Analysis ◽

Energy Band Gap ◽

Melt Compounding ◽

Composite Energy

Synthetic polymer/TiO2 composite such as Polystyrene/TiO2 has become recent highly research materials due to its potential and significant application in various fields. we can tune the polymer and nanoparticles by different techniques such as change the materials concentration, Exposure of materials to laser radiation, Exposure of materials to laser radiation, especially in tuning the polystyrene/TiO2 composite energy band gap. In this review, several methods of preparation are briefly explored such as pan-milling, precipitation, melt compounding, dip-coating, solution cast, and sol-gel method. Some recent advancement that focuses on the two basic elements: polymer and TiO2 are also included especially discussing on photocatalytic degradation that introduces photon as manipulate parameter to tune the polymer/TiO2 composite energy band gap. Scanning electron microscope (SEM) analysis of various polymer/TiO2 (type n concentration) and Polystyrene/TiO2 (concentration and nanoparticles sizes) are the focus of the discussion before exposure to laser radiation as photodegradation source.

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Effects of phosphorus-doping on energy band-gap, structural, surface, and photocatalytic characteristics of emulsion-based sol-gel derived TiO 2 nano-powder

Applied Surface Science ◽

10.1016/j.apsusc.2017.04.103 ◽

2017 ◽

Vol 414 ◽

pp. 277-291 ◽

Cited By ~ 12

Author(s):

Ibram Ganesh

Keyword(s):

Band Gap ◽

Energy Band ◽

Sol Gel ◽

Energy Band Gap ◽

Phosphorus Doping ◽

Nano Powder ◽

Structural Surface

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Facile Synthesis, Diffused Reflectance Spectroscopy & Fluorescence Studies of Ni0.5-xMg0.5CuxFe2O4 Nanoparticles

10.21203/rs.3.rs-174488/v1 ◽

2021 ◽

Author(s):

Pradeep Chavan

Keyword(s):

Grain Size ◽

Band Gap ◽

Energy Band ◽

Fluorescence Emission ◽

Ferrite Nanoparticles ◽

Energy Band Gap ◽

Visible Absorption ◽

Structural Formation ◽

Fluorescence Studies ◽

Auto Combustion

Abstract The present study focused on the structural, morphological, optical and fluorescence properties of Ni 0.5-x Mg 0.5 Cu x Fe 2 O 4 (x = 0.0, 0.1, 0.3 and 0.5) nanoparticles synthesized by using auto combustion technique. The structural formation of the ferrite nanoparticles were confirmed by FTIR spectroscopic study. From FTIR spectra of the synthesized ferrite nanoparticles, metal ions are situated in two different sub lattices i.e. tetrahedral (A-site) and octahedral (B-site) in ferrites. The surface morphology and grain size of Cu substituted Ni-Mg ferrite nanoparticles were estimated from the micrographs of atomic force microscopy (AFM); the maximum grain size 54.69 nm was obtained. Spectra of UV-Visible absorption of the synthesized ferrite nanoparticles were carried-out by using UV-Vis spectrophotometry; the maximum absorption was observed at 418 nm. The energy band gap of ferrite nanoparticles has been estimated using UV-Vis absorption spectra; the energy band gap 3.50 eV was obtained. From the fluorescence emission spectroscopy of synthesized ferrite nanoparticles, the ferrite samples emit red colour in the region of 680 nm.

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Influence Different Compositions of (1-x)ZnFe2O4 – xSiO2 Nanostructures Thin Film Synthesized by Sol-Gel Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.846.607 ◽

2016 ◽

Vol 846 ◽

pp. 607-613

Author(s):

Mohd Syafiq Zulfakar ◽

Huda Abdullah ◽

Wan Nasarudin Wan Jalal ◽

Zalita Zainuddin ◽

Sahbudin Shaari

Keyword(s):

Band Gap ◽

Energy Band ◽

Dielectric Material ◽

Sol Gel ◽

Dielectric Substrate ◽

Face Centered Cubic ◽

Energy Band Gap ◽

Gel Method ◽

Sol Gel Method ◽

Result Analysis

SiO2 compound was introduced into zinc ferrite using formula (1-x)ZnFe2O4 – xSiO2 synthesized by sol-gel method where distilled water and citric acid was used as a solvent and binder agent. The produced samples were annealed at 450 °C for 1h. The AFM result analysis show that the average surface roughness and particle size decreased as the compositions of x was increased. XRD results analysis confirmed the formation of spinel structures with crystallite size within range 11.27 – 4.72 nm. UV-Vis analysis to determine the energy band gap of the (1-x)ZnFe2O4 – xSiO2 samples. It shows that the energy band gap increased as the composition of SiO2 was increased due to the dielectric properties of silicon dioxide. FTIR results analysis exhibit common band in the range of 400 – 4000 cm-1. The observed band near 2350 cm-1 shows the presence of oxygen-oxygen bond in the face centered cubic (fcc) crystal lattice of oxygen atoms. The addition of SiO2 into ZnFe2O4 will help to enhance the morphological structures and optical properties. This new proposed dielectric material can be used as dielectric substrate microstrip patch antenna.

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