scholarly journals Crystal Chemistry, Rietveld Analysis, Structural and Electrical Properties of Cobalt-Erbium Nano-Ferrites

2021 ◽  
Author(s):  
Edapalli Sumalatha ◽  
Dachepalli Ravinder ◽  
Nyathani Maramu ◽  
Shubha ◽  
Butreddy Ravinder Reddy ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrical Resistivity ◽  
Electrical Properties ◽  
Crystallite Size ◽  
Rietveld Analysis ◽  
Tem Analysis ◽  
Lattice Volume ◽  
Edax Analysis ◽  
Cobalt Ferrites ◽  
Structural Variables

Synthesis of Cobalt-Erbium nano-ferrites with formulation CoErxFe2-xO4 (x = 0, 0.005, 0.010, 0.015, 0.020, 0.025, and 0.030) using technique of citrate-gel auto-combustion was done. Characterization of prepared powders was done by using XRD, EDAX, FESEM, AFM and FTIR Spectroscopy, DC resistivity properties respectively. XRD Rietveld Analysis, SEM, TEM and EDAX analysis were taken up in studying spectral, structural, magnetic and electrical properties. XRD pattern of CEF nano particles confirm single phase cubic spinal structure. The structural variables given by lattice constant (a), lattice volume (v), average crystallite size (D) and X-ray density(dx), Bulk density (d), porosity (p), percentage of pore space (P%), surface area (s), strain (ε), dislocation density (δ), along with ionic radii, bond length and hoping length were calculated. SEM and TEM results reveal homogeneous nature of particles accompanied by clusters having no impurity pickup. TEM analysis gives information about particle size of nanocrystalline ferrite while EDAX analysis confirm elemental composition. Emergence of two arch shaped frequency bands (ν1 and ν2) that represent vibrations at tetrahedral site (A) and octahedral site(B) was indicated by spectra of FTIR. The samples electrical resistivity (DC) was measured between 30°C -600°C with Two probe method. XRD Rietveld analysis confirm crystallite size lying between 20.84 nm–14.40 nm while SEM analysis indicate formation of agglomerates and TEM analysis indicate particle size ranging between 24 nm–16 nm. DC Electrical measurements indicate continuous decrease in resistivity with increasing temperature while increasing doping decreases curie temperature. The Magnetic parameters such as Saturation magnetization (Ms), Remanent magnetization (Mr), Coercivity (Hc) and Squareness ratio (R = Mr/Ms), Magnetic moment (nB) were altered by doping of Er+3 content in the increasing order (x = 0.00 to 0.030). The increasing erbium content decreases magnetization thus converting the sample into soft magnetic material. Observations indicated strong dependence of magnetic properties on Erbium substitution and coercivity varies in accordance with anisotropy constant. Due to the presence of magnetic dipole Erbium substituted cobalt ferrites can be used in electromagnetic applications. The present study investigates the effect of different compositions of Er3+ replaced for Fe on structural properties and electrical resistivity of cobalt ferrites.

scholarly journals Eco-Friendly Synthesis, TEM and Magnetic Properties of Co-Er Nano-Ferrites

2021 ◽  
Vol 12 (1) ◽  
pp. 910-928
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Crystallite Size ◽  
Rietveld Analysis ◽  
Sem Analysis ◽  
Tem Analysis ◽  
Edax Analysis ◽  
Cobalt Ferrites ◽  
Auto Combustion ◽  
Structural And Magnetic Properties

Synthesis of Cobalt-Erbium nano-ferrites with formulation CoErxFe2-xO4 (x = 0, 0.005, 0.010, 0.015, 0.020, 0.025, and 0.030) using technique of citrate-gel auto-combustion was done. Characterization of prepared powders was done using XRD, EDAX, FESEM, TEM, AFM, and FTIR spectroscopy, VSM: magnetic properties, respectively. XRD Rietveld Analysis, SEM, TEM, and EDAX analysis studied spectral, structural, and magnetic properties. XRD pattern of CEF nanoparticles confirms single-phase cubic spinal structure. The structural variables are given by lattice constant (a), lattice volume (v), the average crystallite size (D) and X-ray density (dx), bulk density (d), porosity (p), percentage of pore space (P%), surface area (s), strain(ε), dislocation density (δ), along with ionic radii, bond length and hoping length were calculated. SEM and TEM results reveal the homogeneous nature of particles accompanied by clusters having no impurity pickup. TEM analysis gives information about the particle size of nanocrystalline ferrite, while EDAX analysis confirms elemental composition. The emergence of two arch-shaped frequency bands (ν_1 and〖 ν〗_2) that represent vibrations at the tetrahedral site (A) and octahedral site(B) was indicated by spectra of FTIR. The XRD Rietveld analysis confirms crystallite size lying between 20.84 nm-14.40 nm, while SEM analysis indicates the formation of agglomerates and TEM analysis indicates particle size ranging between 24nm-16 nm. The XRD Rietveld analysis confirms crystallite size lying between 20.84nm-14.40nm, while SEM analysis indicates the formation of agglomerates and TEM analysis indicates particle size ranging between 24 nm - 16 nm. The magnetization measurements indicated that increasing Er3+ content in cobalt ferrites decreases magnetization from 60emu/g to 42emu/g while coercivity decreases (18990) as compared to CoFe2O4 (18998) in cobalt ferrites with doping. The present study investigates the effect of different compositions of Er3+ replaced for Fe on structural and magnetic properties of cobalt ferrites.

scholarly journals Synthesis of Hydronium-Potassium Jarosite; Effect of pH and Aging Time on their Structural, Morphological and Electrical Properties

2020 ◽  
Author(s):  
Elías Hernández-Lazcano ◽  
E. Cerecedo-Sáenz ◽  
J. Hernández-Ávila ◽  
Norman Toro ◽  
T.V.K. Karthik ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrical Properties ◽  
Aging Time ◽  
Anode Materials ◽  
Lithium Ion ◽  
Life Time ◽  
Rietveld Analysis ◽  
Morphological Properties ◽  
Hydronium Jarosite ◽  
Cationic Site

Structural and morphological properties of the hydronium-potassium jarosite microstructures were investigated in this work, and their electrical properties were evaluated. All microstructures were synthesized at a reasonable temperature of 343 K with a reduced reaction time of 3 hours. Increase in the pH from 0.8 to 2.1 decreased the particle sized from 3 µm to 200 nm and increasing the aging time from 0, 3 to 7 days resulted in semispherical, spherical and euhedreal jarosite structures, respectively. A Rietveld analysis also was done, finding that increasing pH, the amount of hydronium substitution by potassium in the cationic site also increases, having a 77.72 % of hydronium jarosite (JH) plus 22.29 % potassium jarosite (JK) at pH 0.8; 82.44 % (JH) and 17.56 % (JK) at pH 1.1, and 89.98 % (JH) plus 10.02 % (JK) at pH 2.1. The results obtained in this work show that the obtained hydronium potassium jarosite microstructures with reduced particle size and euhedreal morphology can be used as anode materials for improving the life time of lithium ion batteries, due that during the analysis of the voltage obtained using electrodes made with this particles and graphite, this ranged from 0.89 to 1.36 V.

scholarly journals Crystallite size dependence of thermoelectric performance of CuCrO2

RSC Advances ◽  
2016 ◽  
Vol 6 (94) ◽  
pp. 91171-91178 ◽  
Author(s):  
T. N. M. Ngo ◽  
T. T. M. Palstra ◽  
G. R. Blake
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Electrical Resistivity ◽  
Crystallite Size ◽  
Size Dependence ◽  
Thermoelectric Performance ◽  
Particle Size And Morphology ◽  
Size And Morphology

The thermoelectric performance of CuCrO2 with different particle size and morphology is influenced more by electrical resistivity than thermal conductivity.

The effect of Tin additionon on Structural and magnetic properties of the stannoferrite Li0.5+0.5XFe2.5-1.5XSnXO4

2016 ◽  
Vol 12 (3) ◽  
pp. 4307-4321 ◽  
Author(s):  
Ahmed Hassan Ibrahim ◽  
Yehia Abbas
Keyword(s):  
Particle Size ◽  
Fine Particles ◽  
Magnetic Moments ◽  
Lithium Ferrite ◽  
Tem Analysis ◽  
Weiss Temperature ◽  
X Ray ◽  
Two Phases ◽  
Nanocrystalline Ferrite ◽  
20 Nm

The physical properties of ferrites are verysensitive to microstructure, which in turn critically dependson the manufacturing process.Nanocrystalline Lithium Stannoferrite system Li0.5+0.5XFe2.5-1.5XSnXO4,X= (0, 0.2, 0.4, 0.6, 0.8 and 1.0) fine particles were successfully prepared by double sintering ceramic technique at pre-sintering temperature of 500oC for 3 h andthepre-sintered material was crushed and sintered finally in air at 1000oC.The structural and microstructural evolutions of the nanophase have been studied using X-ray powder diffraction (XRD) and the Rietveld method.The refinement results showed that the nanocrystalline ferrite has a two phases of ordered and disordered phases for polymorphous lithium Stannoferrite.The particle size of as obtained samples were found to be ~20 nm through TEM that increases up to ~ 85 nmand isdependent on the annealing temperature. TEM micrograph reveals that the grains of sample are spherical in shape. (TEM) analysis confirmed the X-ray results.The particle size of stannic substituted lithium ferrite fine particle obtained from the XRD using Scherrer equation.Magneticmeasurements obtained from lake shore’s vibrating sample magnetometer (VSM), saturation magnetization ofordered LiFe5O8 was found to be (57.829 emu/g) which was lower than disordered LiFe5O8(62.848 emu/g).Theinterplay between superexchange interactions of Fe3+ ions at A and B sublattices gives rise to ferrimagnetic ordering of magnetic moments,with a high Curie-Weiss temperature (TCW ~ 900 K).

Solid Lipid Nanoparticles for Topical Delivery of Acitretin for the Treatment of Psoriasis by Design of Experiment

2020 ◽  
Vol 12 (2) ◽  
pp. 4474-4491
Author(s):  
Rajkumar Aland ◽  
Ganesan M ◽  
P. Rajeswara Rao ◽  
Bhikshapathi D. V. R. N.
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Solid Lipid Nanoparticles ◽  
Drug Loading ◽  
Entrapment Efficiency ◽  
Lipid Nanoparticles ◽  
Tem Analysis ◽  
In Vitro Drug Release ◽  
Solid Lipid

The main objective for this investigation is to develop and optimize the solid lipid nanoparticles formulation of acitretin for the effective drug delivery. Acitretin loaded SLNs were prepared by hot homogenization followed by the ultrasonication using Taguchi’s orthogonal array with eight parameters that could affect the particle size and entrapment efficiency. Based on the results from the analyses of the responses obtained from Taguchi design, three different independent variables including surfactant concentration (%), lipid to drug ratio (w/w) and sonication time (s) were selected for further investigation using central composite design. The  lipid Dynasan-116, surfactant poloxomer-188 and co surfactant egg lecithin resulted in better percent drug loading and evaluated for particle size, zeta potential, drug entrapment efficiency, in vitro drug release and stability. All parameters were found to be in an acceptable range. TEM analysis has demonstrated the presence of individual nanoparticles in spherical shape and the results were compatible with particle size measurements.  In vitro drug release of optimized SLN formulation (F2) was found to be 95.63 ± 1.52%, whereas pure drug release was 30.12 after 60 min and the major mechanism of drug release follows first order kinetics release data for optimized formulation (F2) with non-Fickian (anomalous) with a strong correlation coefficient (R2 = 0.94572) of Korsemeyer-Peppas model. The total drug content of acitretin gel formulation was found to 99.86 ± 0.012% and the diameter of gel formulation was 6.9 ± 0.021 cm and that of marketed gel was found to be 5.7 ± 0.06 cm, indicating better spreadability of SLN based gel formulation. The viscosity of gel formulation at 5 rpm was found to be 6.1 x 103 ± 0.4 x 103 cp. The release rate (flux) of acitretin across the membrane and excised skin differs significantly, which indicates about the barrier properties of skin. The flux value for SLN based gel formulation (182.754 ± 3.126 μg cm−2 h−1) was found to be higher than that for marketed gel (122.345 ± 4.786 μg cm−2 h−1). The higher flux and Kp values of SLN based gel suggest that it might be able to enter the skin easily as compared with marketed gel with an advantage of low interfacial tension of the emulsifier film that ensures an excellent contact to the skin. This topically oriented SLN based gel formulation could be useful in providing site-specific dermal treatment of psoriasis

scholarly journals Synthesis of Hydronium-Potassium Jarosites: The Effect of pH and Aging Time on Their Structural, Morphological, and Electrical Properties

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 80
Author(s):  
Elías Hernández-Lazcano ◽  
E. Cerecedo-Sáenz ◽  
J. Hernández-Ávila ◽  
Norman Toro ◽  
T. V. K. Karthik ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Aging Time ◽  
Anode Materials ◽  
Lithium Ion ◽  
Rietveld Analysis ◽  
Morphological Properties ◽  
Particle Sizes ◽  
Ph Values ◽  
Hydronium Jarosite ◽  
Cationic Site

Structural and morphological properties of hydronium-potassium jarosite microstructures were investigated in this work, and their electrical properties were evaluated. All the microstructures were synthesized at a very low temperature of 70 °C with a reduced reaction time of 3 h. An increase in the pH from 0.8 to 2.1 decreased the particle sizes from 3 µm to 200 nm and an increase in the aging time from zero, three, and seven days resulted in semispherical, spherical, and euhedral jarosite structures, respectively. The Rietveld analysis also confirmed that the amount of hydronium substitution by potassium in the cationic site increased with an increase in pH. The percentages of hydronium jarosite (JH)/potassium jarosite (JK) for pH values of 0.8, 1.1, and 2.1 were 77.72/22.29%, 82.44/17.56%, and 89.98/10.02%, respectively. Microstructures obtained in this work were tested as alternative anode materials and the voltage measured using these electrodes made with hydronium-potassium jarosite microstructures and graphite ranged from 0.89 to 1.36 V. The results obtained in this work show that with reduced particle size and euhedral morphology obtained, modified jarosite microstructures can be used as anode materials for improving the lifetime of lithium-ion batteries.

A Simple Dissolved Metals Mixing Route to Prepare Nanostructured Mg0.8Zn0.2TiO3 Solid Solution

2015 ◽  
Vol 1112 ◽  
pp. 47-52 ◽  
Author(s):  
Frida Ulfah Ermawati ◽  
Suasmoro Suasmoro ◽  
Suminar Pratapa
Keyword(s):  
Solid Solution ◽  
Particle Size ◽  
Rietveld Analysis ◽  
Dissolved Metals ◽  
Intermediate Phases ◽  
Particle Size Analyzer ◽  
Ft Ir ◽  
Xrd Patterns ◽  
Zn Ions

A study of liquid mixing route to synthesize high purity Mg0.8Zn0.2TiO3 nanopowder, a candidate dielectric ceramics, has been successfully performed. Formation of the phases on the dried powder was studied using TG/DTA, XRD and FT-IR data. Rietveld analysis on the collected XRD patterns confirmed the formation of solid solution in the system. Such solid solution can be obtained from the powder calcined at 500 °C, but calcination at 550 °C gave rise to the most optimum molar purity up to 98.5% without intermediate phases. The role of Zn ions on the formation of solid solution was also discussed. Homogeneity of particle size distribution and nano-crystallinity of the system was verified from the particle size analyzer data, TEM image and the Rietveld analysis output.

Probing the Effect of High Energy Ball Milling on the Structure and Properties of LiNi1/3Mn1/3Co1/3O2 Cathodes for Li-Ion Batteries

2016 ◽  
Vol 13 (3) ◽  
Author(s):  
Malcolm Stein ◽  
Chien-Fan Chen ◽  
Matthew Mullings ◽  
David Jaime ◽  
Audrey Zaleski ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrochemical Performance ◽  
Crystallite Size ◽  
Ball Milling ◽  
Lithium Ion ◽  
High Energy ◽  
Li Ion Batteries ◽  
Structure And Properties ◽  
Transfer Resistance ◽  
Li Ion

Particle size plays an important role in the electrochemical performance of cathodes for lithium-ion (Li-ion) batteries. High energy planetary ball milling of LiNi1/3Mn1/3Co1/3O2 (NMC) cathode materials was investigated as a route to reduce the particle size and improve the electrochemical performance. The effect of ball milling times, milling speeds, and composition on the structure and properties of NMC cathodes was determined. X-ray diffraction analysis showed that ball milling decreased primary particle (crystallite) size by up to 29%, and the crystallite size was correlated with the milling time and milling speed. Using relatively mild milling conditions that provided an intermediate crystallite size, cathodes with higher capacities, improved rate capabilities, and improved capacity retention were obtained within 14 μm-thick electrode configurations. High milling speeds and long milling times not only resulted in smaller crystallite sizes but also lowered electrochemical performance. Beyond reduction in crystallite size, ball milling was found to increase the interfacial charge transfer resistance, lower the electrical conductivity, and produce aggregates that influenced performance. Computations support that electrolyte diffusivity within the cathode and film thickness play a significant role in the electrode performance. This study shows that cathodes with improved performance are obtained through use of mild ball milling conditions and appropriately designed electrodes that optimize the multiple transport phenomena involved in electrochemical charge storage materials.

(La0.8Sr0.2)MnO3-Ni composite for the interconnect of solid oxide cells: effect of starting Ni particle size on sintering and electrical properties

2021 ◽  
Vol 56 (31) ◽  
pp. 17721-17731
Author(s):  
Fen Qin ◽  
Anqi Wang ◽  
Jong-Sung Park ◽  
Sun-Dong Kim ◽  
Sang Kook Woo ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrical Properties ◽  
Solid Oxide

Relationship of Electrical Properties and Partical Size of Piezoelectric Ceramics Fabricated by Digital Light Processing 3D Printing

2021 ◽  
Author(s):  
Kai Liu ◽  
Jiaming Hu ◽  
Yusheng Shi ◽  
Chenyang Zhou ◽  
Yunfei Sun ◽  
...  
Keyword(s):  
Particle Size ◽  
Electrical Properties ◽  
3D Printing ◽  
Piezoelectric Sensor ◽  
Piezoelectric Ceramics ◽  
Particle Sizes ◽  
Digital Light Processing ◽  
Relationship Of ◽  
Partical Size ◽  
Functional Ceramics

Abstract To improve electrical properties of BaTiO3 piezoelectric ceramics fabricated by 3D printing, effects of particle sizes was investigated on rheological and curing properties of ceramic slurries, electrical properties of BaTiO3 fabricated by Digital Light Processing 3D printing method. It was found that the curing ability of ceramic slurries decreased first and then increased with the increase of particle size from 136 nm to 1486 nm, while the viscosity of the slurries kept decreasing. When the particle size in a range of submicron, the grain size of sintered ceramics decreased from 13.27 μm to 6.84 μm as particle size increasing. Immediately, the relative density, piezoelectric constant, relative permittivity and remanent polarization of sintered ceramics were measured and it turns out to reach 95.32%, 161.4 pC/N, 1512 and 7.59 uC/cm2 respectively while using the BaTiO3 powder with particle sizes of 993 nm. Finally, a cellular structural BaTiO3 ceramics was fabricated by using optimized powder and process parameters and packaged as a piezoelectric sensor, showing a good function of force-electricity conversion. These results demonstrated the feasibility of fabricating high-quality functional ceramics with designed geometry by Digital Light Processing.

Sign in / Sign up

Export Citation Format

Share Document