scholarly journals Enhancement in DC Electrical Resistivity and Dielectric Behaviour of Ti4+ Doped CoFe2O4 NP’s for Nanoelectronics Application

2020 ◽  
Vol 9 (6) ◽  
pp. 257-262
Keyword(s):  
Cobalt Ferrite ◽  
Average Crystallite Size ◽  
Information Storage ◽  
Dielectric Behaviour ◽  
X Ray Diffraction ◽  
Dielectric Parameters ◽  
Phase Spinel ◽  
Vibrational Bands ◽  
Ft Ir ◽  
Xrd Patterns

Inverse spinel structured cobalt ferrite is one of the capable nominee for information storage and also in nanoelectronics devices. The present paper reports the rietveld refined structural, elastic, electrical and dielectric behaviour of titanium doped CoFe2O4 NP’s. The synthesis of Co1+xTixFe2-2xO4 (where, 0.0  x  0.5) nanoparticles was performed using self generated combustion technique. The prepared NP’s were characterized by X-ray diffraction technique (XRD) and Fourier transform infrared spectroscopy (FT-IR) technique to analyze the structural and elastic properties. The analysis of XRD patterns confirms the formation of single phase spinel cubic structure of all the prepared samples. The diffractograms obtained at room temperature were used for Rietveld refinement to determine the lattice constant, oxygen position, average crystallite size etc. parameters. The elastic modules were investigated through vibrational bands in FTIR spectra. The band positions in FT-IR spectra confirmed the octahedral [B] and tetrahedral (A) stretching which evident the ferrite skeleton. The plot of DC electrical resitivity with respect to temperature shows the semiconducting behaviour of the nanoparticles. The activation energy determined through resistivity plots, show decreasing nature with incrementing Ti4+ doping in cobalt ferrite. The dielectric parameters decreased exponentially with increasing frequency and with Ti doping.

Synthesis and characterization of magnetic Ni0.3 Zn0.7 Fe2 O4/polyvinyl acetate (PVAC) nanocomposite

2014 ◽  
Vol 34 (9) ◽  
pp. 823-828
Author(s):  
Fatemeh S. Mohammad Doulabi ◽  
Mohsen Mohsennia ◽  
Shervin Taraghikhah
Keyword(s):  
Magnetic Nanoparticles ◽  
Polyvinyl Acetate ◽  
Nickel Chloride ◽  
X Ray Diffraction ◽  
Phase Spinel ◽  
Ft Ir ◽  
Xrd Patterns ◽  
Synthesized Materials

Abstract The magnetic Ni0.3 Zn0.7 Fe2 O4 nanoparticles were expected to have wide applications in bionanoscience and electronic devices technology. In this work, Ni0.3 Zn0.7 Fe2 O4 nanoparticles were synthesized successfully by a redox chemical reaction in an aqueous solution of nickel chloride, zinc chloride and ferric chloride. Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the shape, structure and size of the synthesized magnetic nanoparticles. The magnetic properties of Ni0.3 Zn0.7 Fe2 O4 nanoparticles were studied using a vibrating sample magnetometer (VSM). The XRD patterns of the synthesized nanoparticles revealed the formation of the single phase spinel structure of the synthesized materials. The synthesized Ni0.3 Zn0.7 Fe2 O4 nanoparticles were used for the preparation of Ni0.3 Zn0.7 Fe2 O4/polyvinyl acetate (PVAC) nanocomposites by an in situ emulsion polymerization method. The synthesized Ni0.3 Zn0.7 Fe2 O4 nanoparticles exhibited superparamagnetic behavior at the room temperature under an applied magnetic field. Magnetization measurements indicated that the saturation magnetization of synthesized Ni0.3 Zn0.7 Fe2 O4/PVAc nanocomposites was markedly less than that of Ni0.3 Zn0.7 Fe2 O4 magnetic nanoparticles.

STRUCTURE AND MAGNETIC PROPERTIES OF MECHANICAL ALLOYED Mn-15at.%Al

2013 ◽  
Vol 12 (01) ◽  
pp. 1350006
Author(s):  
AHMED E. HANNORA ◽  
FARIED F. HANNA ◽  
LOTFY K. MAREI
Keyword(s):  
Thermal Analysis ◽  
Room Temperature ◽  
Average Crystallite Size ◽  
Al Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Milled Sample ◽  
Powder Samples ◽  
Xrd Patterns ◽  
Method Analysis

Mechanical alloying (MA) method has been used to produce nanocrystallite Mn -15at.% Al alloy. X-ray diffraction (XRD) patterns for the as-milled elemental α- Mn and aluminum powder samples show a mixture of α + β- MnAl phases after 20 h of milling and changes to a dominant β- MnAl phase structure after 50 h. An average crystallite size of 40 nm was determined from Hall–Williamson method analysis after 5 h of milling. Moreover, the thermal analysis results using differential thermal analysis (DTA), suggested a possible phase transformation after 20 h of milling. Isothermal treatments are carried in the temperature range of 450°C to 1000°C. Room-temperature vibrating sample magnetometer (VSM) measurements of the hysteretic response revealed that the saturation magnetization Bs and coercivity Hc for 10 h ball milled sample are ~ 2.1 emu/g and ~ 92 Oe, respectively.

scholarly journals Mechanochemical Synthesis of Fluorapatite-Zinc Oxide (FAp-ZnO) Composite Nanopowders

ISRN Ceramics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Bahman Nasiri-Tabrizi ◽  
Abbas Fahami
Keyword(s):  
Zinc Oxide ◽  
Average Crystallite Size ◽  
Structural Features ◽  
Morphological Features ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Remarkable Change ◽  
X Ray ◽  
Process Characterization ◽  
Ft Ir

Fluorapatite-zinc oxide (FAp-ZnO) composite nanopowders were successfully prepared via mechanochemical process. Characterization of the products was carried out by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) analysis, energy dispersive X-ray spectroscopy (EDX), and field-emission scanning electron microscopy (FE-SEM) techniques. Results revealed that in the absence of ZnO which produced by hydrothermal method, the single-phase FAp had high-crystalline structure with appropriate morphological features. Furthermore, after 5 h of milling in the presence of 5 wt.% ZnO, FAp-5 wt.% ZnO, composite nanopowders with no impurity phase was obtained. Structural studies illustrated that the milling up to 5 h was not accompanied by a remarkable change in the structural features. Moreover, the gained composite powders presented an average crystallite size of about 40 nm for FAp. The FE-SEM observations indicated that the experimental outcome had a cluster-like structure which consisted of several small particles. Finally, results propose a new approach to prepare commercial amounts of novel FAp-based composite nanopowders with high quality and suitable structural and morphological features.

scholarly journals FTIR and Optical Properties of NiO Doped Cr2O3 Nanopar-ticles Synthesis by Hydrothermal Method

2018 ◽  
Vol 29 (1) ◽  
pp. 168
Author(s):  
Tunis Balassim Hassan
Keyword(s):  
Optical Band Gap ◽  
Average Crystallite Size ◽  
Structural Behavior ◽  
X Ray Diffraction ◽  
Nanopar Ticles ◽  
Hydrothermal Technique ◽  
X Ray ◽  
Cr2o3 Nanoparticles ◽  
Xrd Patterns ◽  
Scanning Electron

Pure and Nickel oxide doped chromium (III) oxide (Cr2O3) nanoparticals are synthesized by hydrothermal technique. The effect of dopant Ni concentration on the structural behavior of Cr2O3 nanoparticles was examined by X-ray diffraction. The average crystallite size of the synthesized nanoparticles was measured from XRD patterns using Scherrer equation and was decreased from 22nm to 12.9 nm with the increasing Nio concentration in Cr2O3 from (0, 0.01, 0.06, and 0.10). Morphologies and compositional elements of the synthesized nanoparticles were observed by the field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) spectroscopy, respectively. The optical property of the samples was measured by ultraviolet - visible (UV-Vis.) absorption spectroscopy. The observed optical band gap value ranges from 2.3eV to 2.5eV for Ni doped nanoparticles

The Effect of Rare Earth Modification on the Structure and Catalytic Performance of SO42-/ZrO2 Solid Acid Catalysts

2011 ◽  
Vol 287-290 ◽  
pp. 1375-1378
Author(s):  
Ying Chen ◽  
Bao Hui Wang ◽  
Xue Sun ◽  
Hui Li
Keyword(s):  
Rare Earth ◽  
Solid Acid ◽  
Tetragonal Zirconia ◽  
Acid Methyl Ester ◽  
Catalytic Performance ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Xrd Patterns

Rare earth modified SO2-4/ZrO2 solid acid catalysts were prepared by coprecipitation and impregnation methods respectively. The properties of the samples were characterized by XRD (X-ray diffraction), FT-IR (Fourier transform infrared spectroscopy). And their catalytic performances were evaluated and investigated by transesterification of waste oil with methanol. The results showed that the catalyst containing 4% Ce and calcined at 550°C displayed the highest production rate and the better reuse ability than the others. 63.5% yield of fatty acid methyl ester was achieved. An analysis of XRD patterns reveal that the incorporation of rare earth into tetragonal zirconia stabilizes the compound, and the calcination at 550°C increases the reactivity of the catalyst by producing a greater fraction of active tetragonal zirconia. It can be seen from the FT-IR spectra that superacids structures are formed in the catalysts and the acidity is strengthened remarkably and the activated centre of the catalyst were increasesed.

scholarly journals Synthesis of BaTi5O11 by an aqueous co-precipitation method via stable organic titanate precursor

2021 ◽  
pp. 14-14
Author(s):  
Pelin Aktaş
Keyword(s):  
Aqueous Media ◽  
Average Crystallite Size ◽  
Phase Evolution ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Ft Ir ◽  
Scherrer Formula ◽  
Co Precipitation

BaTi5O11 has been widely researched due to its unique microwave properties. Conventionally it is challenging to obtain this compound as a single phase. The BaTi5O11 was synthesized via co-precipitation technique using an aqueous solution of titanium(IV)(triethanolaminato) isopropoxide, barium nitrate and ammonia as precursors which are stable in an aqueous media. The phase evolution, purity, and structure were identified by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy analysis. The desired BaTi5O11 structure was obtained by calcination at 900?C. Furthermore, the structure is characterized by TGA, FT-IR and Raman studies. The study showed that the particles were between 80 and 120 nm in size and the average crystallite size was determined from the Scherrer formula as 68.1 nm at 900?C.

scholarly journals Boost the Crystal Installation and Magnetic Features of Cobalt Ferrite/M-Type Strontium Ferrite Nanocomposites Double Substituted by La3+ and Sm3+ Ions (2CoFe2O4/SrFe12−2xSmxLaxO19)

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7820
Author(s):  
Mahmoud M. Hessien ◽  
Ali Omar Turky ◽  
Abdullah K. Alanazi ◽  
Mohammed Alsawat ◽  
Mohamed H. H. Mahmoud ◽  
...  
Keyword(s):  
Saturation Magnetization ◽  
Crystallite Size ◽  
Cobalt Ferrite ◽  
Average Crystallite Size ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
Ion Substitution ◽  
Double Substitution ◽  
Lanthanum Cobalt Oxide ◽  
Co Doped

Spinel cobalt ferrite/hexagonal strontium hexaferrite (2CoFe2O4/SrFe12−2xSmxLaxO19; x = 0.2, 0.5, 1.0, 1.5) nanocomposites were fabricated using the tartaric acid precursor pathway, and the effects of La3+–Sm3+ double substitution on the formation, structure, and magnetic properties of CoFe2O4/SrFe12−2xSmxLaxO19 nanocomposite at different annealing temperatures were assayed through X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. A pure 2CoFe2O4/SrFe12O19 nanocomposite was obtained from the tartrate precursor complex annealed at 1100 °C for 2 h. The substitution of Fe3+ ion by Sm3–+La3+ions promoted the formation of pure 2CoFe2O4/SrFe12O19 nanocomposite at 1100 °C. The positions and intensities of the strongest peaks of hexagonal ferrite changed after Sm3+–La3+ substitution at ≤1100 °C. In addition, samples with an Sm3+–La3+ ratio of ≥1.0 annealed at 1200 °C for 2 h showed diffraction peaks for lanthanum cobalt oxide (La3Co3O8; dominant phase) and samarium ferrite (SmFeO3). The crystallite size range at all constituent phases was in the nanocrystalline range, from 39.4 nm to 122.4 nm. The average crystallite size of SrFe12O19 phase increased with the number of Sm3+–La3+ substitutions, whereas that of CoFe2O4 phase decreased with an x of up to 0.5. La–Sm co-doped ion substitution increased the saturation magnetization (Ms) value and the subrogated ratio to 0.2, and the Ms value decreased with the increasing number of double substitutions. A high saturation magnetization value (Ms = 69.6 emu/g) was obtained using a La3+–Sm3+ co-doped ratio of 0.2 at 1200 for 2 h, and a high coercive force value (Hc = 1192.0 Oe) was acquired using the same ratio at 1000 °C.

Effect of Polymeric Milling Media on the Mechanosynthesis and Structural Properties of Nanocrystalline Hydroxyapatite

2009 ◽  
Vol 283-286 ◽  
pp. 98-105 ◽  
Author(s):  
Ali Shokuhfar ◽  
Bahman Nasiri-Tabrizi ◽  
Omid Gashti ◽  
Reza Ebrahimi-Kahrizsangi
Keyword(s):  
Crystallite Size ◽  
High Performance ◽  
Average Crystallite Size ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Mechanochemical Process ◽  
Structural Evaluation ◽  
Transmission Electron ◽  
Nanocrystalline Hydroxyapatite ◽  
Xrd Patterns

Mechanochemical process in polymeric vials has been carried out successfully to produce nanocrystalline hydroxyapatite (HAp) through two different reactions R1 and R2. Morphological properties and structural evaluation of obtained materials are studied by X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM). The obtained data show that the increase in milling time leads the increasing in lattice strain and decreasing in crystallite size. The average crystallite size of HAp is below 20 and 23 nm for R1 and R2 reactions, respectively. Based on XRD patterns and SEM/TEM micrographs, the possible formation mechanism of nanocrystalline hydroxyapatite by mechanochemical process in polymeric milling media is confirmed. Final results indicate that the nanocrystalline hydroxyapatite with low chemically stable contaminations and suitable morphology can be produced in Polyamide6 vials similar to stainless steel vials, therefore it seems that using polymeric vials could lead to a new way for the mass production of nanocrystalline hydroxyapatite with high performance, low contamination and cost and also suitable morphology.

scholarly journals Fabrication and characterization of Zn doped CuO nanofiber using newly designed nanofiber generator for the photodegradation of methylene blue from textile effluent

2018 ◽  
Vol 36 (3) ◽  
pp. 520-529 ◽  
Author(s):  
Ramasamy Gopalsamy Sethuraman ◽  
Thangamuthu Venkatachalam ◽  
Selvaraj Dinesh Kirupha
Keyword(s):  
Methylene Blue ◽  
Copper Oxide ◽  
Copper Acetate ◽  
Average Crystallite Size ◽  
Blue Shift ◽  
X Ray Diffraction ◽  
Fourier Transformation Infrared Spectroscopy ◽  
Ft Ir ◽  
The Stability

AbstractHigh aspect ratio, Zn doped copper oxide (Zn-CuO) nanofibers have been fabricated employing a newly designed electrospun coating unit using copper acetate, sodium hydroxide and polyethylene glycol in aqueous state. The prepared Zn doped copper oxide (Zn-CuO) nanofibers were sintered at 400 °C, 500 °C and 600 °C separately and characterized using X-ray diffraction XRD, Fourier transformation infrared spectroscopy FT-IR, scanning electron microscopy SEM, energy dispersive spectroscopy EDS. The average crystallite size was in the range of 28 nm to 30 nm. Optical properties of Zn-CuO nanofibers were analyzed using UV-DRS studies which showed a blue shift in the absorption band. An increase in band gap with the increase in postannealing temperature was observed due to the blue shift in absorption edge of CuO causing enhanced photodegradation. The catalytic properties of the CuO nanofibers were tested using methylene blue in aqueous medium. The influences of parameters responsible for high photodegradation were optimized and the rate of the photodegradation process was calculated using photodegradation kinetics. The reusability test was conducted to find the stability of the fabricated Zn-CuO nanofibers.

Sonochemical Synthesis of Zn3(PO4)2.4H2O and Zn3(PO4)2 Powders

2012 ◽  
Vol 506 ◽  
pp. 94-97 ◽  
Author(s):  
M. Sutapun ◽  
B. Boonchom ◽  
Naratip Vittayakorn
Keyword(s):  
Orthophosphoric Acid ◽  
Zinc Phosphate ◽  
Structural Characteristics ◽  
Synthesis Method ◽  
Sonochemical Method ◽  
X Ray Diffraction ◽  
Sonochemical Synthesis ◽  
X Ray ◽  
Ft Ir ◽  
Xrd Patterns

Zn3(PO4)2.4H2O, which is an important component of biomedical zinc phosphate cement, was synthesized from an aqueous solution of zinc oxide and orthophosphoric acid by the sonochemical method. This synthesis method yielded best results with respect to high purity and crystallinity. Structural characteristics of the compound were investigated by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM). FT-IR spectra indicated the presences of different crystallographic PO43ion and H2O molecules for the Zn3(PO4)2.4H2O and Zn3(PO4)2structures. The resulting XRD patterns showed the purity phases of orthorhombic Zn3(PO4)2.4H2O and the monoclinic for its final decomposed Zn3(PO4)2product. The thermal stability, crystallite size, and plate-like microparticles of Zn3(PO4)2.4H2O and Zn3(PO4)2are different in this work from those in previous reports, which may be caused by the starting reagents and reaction condition for the sonochemical method.

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