Laser induced Fano scattering, electron–phonon coupling, bond length and phonon lifetime changes in α-Fe2O3 nanostructures

2020 ◽  
Vol 22 (4) ◽  
pp. 2001-2009 ◽  
Author(s):  
Anoop Sunny ◽  
Arun Thirumurugan ◽  
Karthikeyan Balasubramanian
Keyword(s):  
Bond Length ◽  
Precipitation Method ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Phonon Lifetime ◽  
Co Precipitation

We have extensively studied the laser-induced Fano scattering, electron–phonon coupling, bond length and phonon lifetime of the α-Fe2O3 nanostructure prepared through a simple co-precipitation method.

scholarly journals NANOPARTICLE FABRICATION OF COxNi1-xFe2O4 (x=0,0.25,0.5,0.75,1.0) USING CO-PRECIPITATION METHODE AT LOW TEMPERATURE

2019 ◽  
Vol 11 (2) ◽  
pp. 52 ◽  
Author(s):  
Muhammad Yakob ◽  
Rachmad Almi Putra
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Bond Length ◽  
Octahedral Site ◽  
Tetrahedral Site ◽  
Cobalt Concentration ◽  
Crystal Defect ◽  
Precipitation Method ◽  
Nanoparticle Fabrication ◽  
Co Precipitation

<p>Nanoparticle Co<sub>x</sub>Ni<sub>1-x</sub>Fe<sub>2</sub>O<sub>4</sub> has been successfully synthesized using co-precipitation method at low temperature 120<sup>o</sup>C by variation of concentration value (x=0; 0.25; 0.5; 0.75; 1.0). Crystal structure and size of crystallite increase with increasing cobalt concentration. There is a difference of lattice between theoretical and experimental. Increase the cobalt concentration in Co<sub>x</sub>Ni<sub>1-x</sub>Fe<sub>2</sub>O<sub>4</sub> nanoparticle affected to the bond length between cation-anion on tetrahedral site and octahedral site. Because of the distortion, the crystallite where imperfectly formed and crystal defect occurred. It is indicated by the microstrain value that describes the magnitude of the strain in crystal.</p>

THE TEMPERATURE DEPENDENCE OF THE HALF-WIDTHS OF INTERNAL ABSORPTION LINES IN BORON-DOPED SILICON

1967 ◽  
Vol 45 (9) ◽  
pp. 2879-2888 ◽  
Author(s):  
R. R. Parsons ◽  
J. W. Bichard
Keyword(s):  
Ground State ◽  
Phonon Coupling ◽  
Boron Doped ◽  
Electron Phonon Coupling ◽  
Doped Silicon ◽  
Internal States ◽  
Phonon Lifetime ◽  
Width Measurements ◽  
Lifetime Effects ◽  
Internal Absorption

For boron-doped silicon at temperatures less than 60 °K, half-width measurements for those absorption peaks corresponding to transitions from the ground state to the 2P′ and 3P′ internal states are presented. These half-widths are attributed to concentration and electron–phonon lifetime effects. The major contribution to the phonon broadening appears to be due to electron–phonon coupling of the internal states to the P3/2 Bloch states.

Magnetic and dielectric properties of BiFeO3 nanoparticles

2015 ◽  
Vol 7 (2) ◽  
pp. 1393-1403
Author(s):  
Dr R.P VIJAYALAKSHMI ◽  
N. Manjula ◽  
S. Ramu ◽  
Amaranatha Reddy
Keyword(s):  
Diffuse Reflectance Spectrum ◽  
Precipitation Method ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Bifeo3 Nanoparticles ◽  
Transmission Electron ◽  
Multiferroic Bifeo3 ◽  
Pure Phase ◽  
Simple Chemical ◽  
Co Precipitation

Single crystalline nano-sized multiferroic BiFeO3 (BFO) powders were synthesized through simple chemical co-precipitation method using polyethylene glycol (PEG) as capping agent. We obtained pure phase BiFeO3 powder by controlling pHand calcination temperature. From X-ray diffraction studies the nanoparticles were unambiguously identified to have a rhombohedrally distorted perovskite structure belonging to the space group of R3c. No secondary phases were detected. It indicates single phase structure. EDX spectra indicated the appearance of three elements Bi, Fe, O in 1:1:3. From the UV-Vis diffuse reflectance spectrum, the absorption cut-off wavelength of the BFO sample is around 558nm corresponding to the energy band gap of 2.2 eV. The size (60-70 nm) and morphology of the nanoparticles have been analyzed using transmission electron microscopy (TEM).   Linear M−H behaviour and slight hysteresis at lower magnetic field is observed for BiFeO3 nanoparticles from Vibrating sample magnetometer studies. It indicates weak ferromagnetic behaviour at room temperature. From dielectric studies, the conductivity value is calculated from the relation s = L/RbA Sm-1 and it is around 7.2 x 10-9 S/m.

Exploring the characterization of Ni doped MgO nanoparticles using co-precipitation method

2020 ◽  
Vol 3 (1) ◽  
pp. 30-33
Author(s):  
Muthulakshmi M ◽  
Madhumitha G
Keyword(s):  
Magnesium Oxide ◽  
Analytical Techniques ◽  
Nickel Chloride ◽  
Precipitation Method ◽  
Crystalline Powder ◽  
High Melting Point ◽  
Design Synthesis ◽  
Mgo Nanoparticles ◽  
Co Precipitation

Nanotechnology is a field of applied science focused on design, synthesis and characterization of nanomaterials. The nickel and magnesium have improved their applications in transparent electrodes and nano electronics. In addition, magnesium oxide has moisture resistance and high melting point properties. In the present work has been carried out in the development of green crystalline powder of nickel doped magnesium oxide nanoparticles by Co-precipitation method, from the mixture of nickel chloride and magnesium chloride with KOH as solvent. From the XRD results, crystalline size of the particle can be observed. Spherical structure of Ni doped MgO nanoparticles were indicated by SEM results and powdered composition of samples were obtained from FTIR. EDAX represents the peak composition of the nanoparticle. The above analytical techniques have confirmed that the Ni doped MgO nanoparticles obtained from the mixture of NiCl2 and MgCl2.

Diseases Prevention by Water Defluoridation Using Hydrotalcites as Decontaminant Materials

2017 ◽  
Vol 68 (1) ◽  
pp. 168-171 ◽  
Author(s):  
Letitia Doina Duceac ◽  
Cristina Elena Dobre ◽  
Ioana Pavaleanu ◽  
Gabriela Calin ◽  
Simona Nichitus ◽  
...  
Keyword(s):  
Dental Fluorosis ◽  
Precipitation Method ◽  
Original Structure ◽  
Fluoride Removal ◽  
Major Goal ◽  
Bone Stiffness ◽  
Morphological Aspects ◽  
Adsorption Capacities ◽  
Interlayer Structure ◽  
Co Precipitation

Preventing diseases is deemed to be the major goal of our century especially when an excessive fluoride in drinking water can cause dental fluorosis, bone stiffness, rheumatism and skeletal fluorosis. Fluoride uptake from groundwater implies a worldwide multidisciplinary effort in order to develop renewable, cheap, human friendly materials. Among other materials, hydrotalcites could be good candidates for an efficient fluoride removal from water due to their adsorption, anion exchange and reconstruction properties. These nanostructured materials were synthesized using co-precipitation method in controlled conditions. Presence of anions in the interlayer structure and morphological aspects were performed by FTIR and SEM techniques. Thermal treatment of hydrotalcites showed good adsorption capacities for water defluoridation mostly due to their tendency to restore the original structure.

Synthesis of highly sinterable YAG nanopowders by a modified co-precipitation method

2007 ◽  
Vol 433 (1-2) ◽  
pp. 328-331 ◽  
Author(s):  
Zhi-Hui Chen ◽  
Yun Yang ◽  
Zhang-Gui Hu ◽  
Jiang-Tao Li ◽  
Shu-Li He
Keyword(s):  
Precipitation Method ◽  
Co Precipitation
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