Influence of Cu on the Improvement of Magnetic Properties and Structure of L10 FePt Nanoparticles

L10 ordered FePt and FePtCu nanoparticles (NPs) with a good dispersion were successfully fabricated by a simple, green, one-step solid-phase reduction method. Fe (acac)3, Pt (acac)2, and CuO as the precursors were dispersed in NaCl and annealed at different temperatures with an H2-containing atmosphere. As the annealing temperature increased, the chemical order parameter (S), average particle size (D), coercivity (Hc), and saturation magnetization (Ms) of FePt and FePtCu NPs increased and the size distribution range of the particles became wider. The ordered degree, D, Hc, and Ms of FePt NPs were greatly improved by adding 5% Cu. The highest S, D, Hc, and Ms were obtained when FePtCu NPs annealed at 750 °C, which were 0.91, 4.87 nm, 12,200 Oe, and 23.38 emu/g, respectively. The structure and magnetic properties of FePt and FePtCu NPs at different annealing temperatures were investigated and the formation mechanism of FePt and FePtCu NPs were discussed in detail.

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Single-Step Synthesis of Manganese Ferrite Nanoparticles with Enhanced Magnetization via Chemical Co-precipitation Route

Journal of Scientific Research ◽

10.3329/jsr.v11i2.39059 ◽

2019 ◽

Vol 11 (2) ◽

pp. 225-234

Author(s):

S. Pande ◽

M. M. Islam ◽

S. C. Mohanta ◽

Nasir Uddin

Keyword(s):

Magnetic Properties ◽

Average Particle Size ◽

Average Crystallite Size ◽

Ferrite Nanoparticles ◽

Single Step ◽

Average Particle ◽

Manganese Ferrite ◽

Xrd Pattern ◽

One Step ◽

Co Precipitation

Single-domain manganese ferrite nanoparticles were synthesized through one-step chemical co-precipitation technique using diethanolamine which acted simultaneously as precipitating and capping agent. The synthesized nanoparticles were characterized by XRD, FTIR, TGA, EDX, FESEM and VSM. XRD pattern showed the presence of peaks corresponding to the single-phase inverse spinel structure with an average crystallite size of 59.6 nm. The average particle size determined by FESEM was 46.8 nm. In addition, the magnetic properties of the nanoparticles analyzed by VSM exhibited nearly superparamagnetic property with a high saturation magnetization of 77.31 emu/g with little coercivity (10.53 emu/g) and remanence (9.32 emu/g) at 300 K temperature. TGA and FTIR results confirmed the binding of diethanolamine onto the surface of manganese ferrite nanoparticles. The synthesized nanoparticles exhibited single crystalline phase with improved magnetic properties.

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Evolution of Microstructure, Precipitate and Magnetic Properties with the Different Annealing Temperature in High Grade Nonoriented Electrical Steels

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.416-417.1645 ◽

2013 ◽

Vol 416-417 ◽

pp. 1645-1651 ◽

Cited By ~ 1

Author(s):

Tie Ye ◽

Cheng Zhou ◽

Zhen Yu Gao

Keyword(s):

Magnetic Properties ◽

Magnetic Induction ◽

Annealing Temperature ◽

Average Particle Size ◽

Second Phase ◽

Average Particle ◽

High Grade ◽

Final Annealing ◽

Electrical Steels ◽

Evolution Of Microstructure

The evolution of microstructure, precipitate and magnetic properties in nonoriented electrical steels with different annealing temperature was studied. The iron loss of steel decreases with an increase in the final annealing temperature ranging from 800~900°C. This phenomenon is associated with grains recovery; recrystallization and grains grow up with the temperature increasing. Grain size continues to increase, but the average particle size decreases and particle density increases at 880~900°C which show precipitates have dissolved. It approved that the dissolution process of a lot of precipitates occurred after grains growing up. Precipitates are mainly of the second phase particles MnS and AlN. The magnetic induction increased firstly at 800~880°C and then increasing at 880~900°C.It can be found that the proportion of the texture for [{100} +Gos/ {111} at 900°C is higher than that at 880°C and the proportion of Gauss texture is higher at 900°C than that at 880°C. Gauss texture in high grade silicon steel plays an important role which promotes magnetic induction to increase.

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Polymer Binders of Ceramic Nanoparticles for Precision Casting of Nickel-Based Superalloys

Nanomaterials ◽

10.3390/nano11071714 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1714

Author(s):

Paweł Wiśniewski

Keyword(s):

Solid Phase ◽

Average Particle Size ◽

Water Soluble ◽

Ethyl Silicate ◽

Average Particle ◽

Precision Casting ◽

Polymer Binders ◽

Initial Stage ◽

Nano Alumina ◽

Solid Phase Content

This study presents the general characteristics of binders used in precision casting of Nickel-based superalloys. Three groups of binders were described: resins, organic compounds, and materials containing nanoparticles in alcohol or aqueous systems. This study also includes literature reports on materials commonly used and those recently replaced by water-soluble binders, i.e., ethyl silicate (ES) and hydrolysed ethyl silicate (HES). The appearance of new and interesting solutions containing nano-alumina is described, as well as other solutions at the initial stage of scientific research, such as those containing biopolymers, biodegradable polycaprolactone (PCL), or modified starch. Special attention is paid to four binders containing nano-SiO2 intended for the first layers (Ludox AM, Ludox SK) and structural layers (EHT, Remasol) of shell moulds. Their morphology, viscosity, density, reactions, and electrokinetic potential were investigated. The binders were characterized by a high solid-phase content (>28%), viscosity, and density close to that of water (1–2 mPa·s) and good electrokinetic stability. The nanoparticles contained in the binders were approximately spherically shaped with an average particle size of 16–25 nm.

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Preparation and Characterization of Terpenoid-Encapsulated PLGA Microparticles and its Antibacterial Activity against Enterococcus faecalis

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.829.263 ◽

2019 ◽

Vol 829 ◽

pp. 263-269

Author(s):

Denny Nurdin ◽

Andri Hardiansyah ◽

Elsy Rahimi Chaldun ◽

Anti Khoerul Fikkriyah ◽

Hendra Dian Adhita Dharsono ◽

...

Keyword(s):

Enterococcus Faecalis ◽

Average Particle Size ◽

Poly Vinyl Alcohol ◽

Prolonged Release ◽

Average Particle ◽

Plga Microparticles ◽

Assay Result ◽

Result Show ◽

One Step

Exploration of natural compound for the treatment of dental-related problems are gaining of interest for enhancing therapeutic efficacy of the drugs delivery system. In this study, we have prepared terpenoid, which have been isolated from Myrmecodia pendens Merr & Perry from Papua Island, Indonesia, to be encapsulated in Polylactic-co-glycolic acid (PLGA), as the most widely used biodegradable polymer for biomedical applications, through one step single-emulsion method followed by subsequent coating by poly (vinyl alcohol) (PVA). The resultant of terpenoid-loaded PLGA microparticles were characterized systematically through scanning electron microscope and Fourier-transform infrared spectroscopy. In vitro drug release test was evaluated through dialysis method. Antibacterial test was conducted against Enterococcus faecalis as a model for persistent bacteria that causes root canal infections. The results showed that terpenoid-loaded PLGA microparticles were developed in spherical morphology with an average particle size of around 1-2μm. Terpenoid released from PLGA compartment at pH 6.5 and temperature of 37°C through a controlled-release profile mechanism with enhanced prolonged release. The bacterial assay result showed that terpenoid-loaded PLGA microparticles could reduce Enterococcus faecalis, effectively. Eventually, these result show that terpenoid-loaded PLGA microparticles as unique natural product-based extract could be developed as a potential naturally-based drug for dental-related diseases applications.

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Investigation of the influence of the mode of heat treatment of the initial powder on the efficiency of sintering zirconium ceramics by dilatometry

Bulletin of the Karaganda University Physics Series ◽

10.31489/2021ph3/17-24 ◽

2021 ◽

Vol 103 (3) ◽

pp. 17-24

Author(s):

S. Shevelev ◽

◽

E. Sheveleva ◽

O. Stary ◽

Keyword(s):

Thermal Annealing ◽

Zirconium Dioxide ◽

Annealing Temperature ◽

Average Particle Size ◽

Average Particle ◽

Sintered Ceramic ◽

Tetragonal Modification ◽

Thermal Sintering ◽

Powder Compacts ◽

High Degree

Using methods of synchronous thermal and X-ray structural analyzes applied to zirconium dioxide powders partially stabilized with yttrium obtained by chemical coprecipitation the processes of dehydration of these powders during annealing in air have been investigated. Using the dilatometry method, the regularities of compaction of powder compacts have been investigated with thermal sintering. It was found that the resulting powders mainly consist of the tetragonal modification zirconium dioxide and are nano-sized. The average particle size was 25 nm. The resulting powders are characterized by a high degree of agglomeration. It is shown that an increase in the thermal annealing temperature from 500 to 700ºС leads to partial baking of individual particles inside the agglomerate, and causes the formation of hard agglomerates, the presence of which complicates the processes of compaction and subsequent sintering. The presence of such agglomerates prevents the production of ceramics with high mechanical characteristics: density and porosity. Thermal annealing temperature increase leads to a decrease in the density of the sintered ceramic and a decrease in its hardness.

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Structural and Magnetic Properties of Co‒Mn Codoped ZnO Nanoparticles Obtained by Microwave Solvothermal Synthesis

Crystals ◽

10.3390/cryst8110410 ◽

2018 ◽

Vol 8 (11) ◽

pp. 410 ◽

Cited By ~ 6

Author(s):

Jacek Wojnarowicz ◽

Myroslava Omelchenko ◽

Jacek Szczytko ◽

Tadeusz Chudoba ◽

Stanisław Gierlotka ◽

...

Keyword(s):

Magnetic Properties ◽

Crystallite Size ◽

Doping Level ◽

Solvothermal Synthesis ◽

Zinc Acetate Dihydrate ◽

Average Particle Size ◽

Average Crystallite Size ◽

Average Particle ◽

Acetate Tetrahydrate ◽

Preparation Methods

Zinc oxide nanoparticles codoped with Co2+ and Mn2+ ions (Zn(1−x−y)MnxCoyO NPs) were obtained for the first time by microwave solvothermal synthesis. The nominal content of Co2+ and Mn2+ in Zn(1−x−y)MnxCoyO NPs was x = y = 0, 1, 5, 10 and 15 mol % (the amount of both ions was equal). The precursors were obtained by dissolving zinc acetate dihydrate, manganese (II) acetate tetrahydrate and cobalt (II) acetate tetrahydrate in ethylene glycol. The morphology, phase purity, lattice parameters, dopants content, skeleton density, specific surface area, average particle size, average crystallite size, crystallite size distribution and magnetic properties of NPs were determined. The real content of dopants was up to 25.0% for Mn2+ and 80.5% for Co2+ of the nominal content. The colour of the samples changed from white to dark olive green in line with the increasing doping level. Uniform spherical NPs with wurtzite structure were obtained. The average size of NPs decreased from 29 nm to 21 nm in line with the increase in the dopant content. Brillouin type paramagnetism and an antiferromagnetic interaction between the magnetic ions was found for all samples, except for that with 15 mol % doping level, where a small ferromagnetic contribution was found. A review of the preparation methods of Co2+ and Mn2+ codoped ZnO is presented.

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Obtaining the conductive SnO2 films by chemical bath deposition method

Butlerov Communications ◽

10.37952/roi-jbc-01/19-60-11-1 ◽

2019 ◽

Vol 60 (11) ◽

pp. 1-10

Author(s):

Vladislav I. Rogozin ◽

◽

Vyacheslav F. Markov ◽

Larisa N. Maskaeva ◽

Anastasia E. Krasovskaya ◽

...

Keyword(s):

Tin Dioxide ◽

Solid Phase ◽

Average Particle Size ◽

Ammonium Fluoride ◽

Contact Layer ◽

Average Particle ◽

Solution Ph ◽

Before And After ◽

Initial Salt ◽

Conductive Properties

Thanks to such unique properties as transparency and conductivity tin dioxide often utilize as transparent contact layer to produce displays, solar cells, and sensor devices. Hydrochemical method of deposition SnO2 films is a perspective due to its simplicity, and economical efficiency. The ionic equilibria analysis was carried out and the boundary conditions of Sn(OH)2 solid phase formation in the «Sn2+ – H2O – OH‾» system calculated. It was established, that tin(II) hydroxide may be obtain in the range 2 < pH < 12. Preliminary results allow to determinate an optimal mixture sourness interval 1 < pH < 5. Revealed, that the thickness of the Sn(OH)2 films strongly depends on the solution pH. Maximum value of 488 nm reached at pH = 8. Conductive SnO2 layers were obtained on a glass and sitall substrates with simultaneously presence of antimony chloride and ammonium fluoride followed by annealing in air. The thickness vs temperature and thickness vs tin initial salt concentration dependences were installed. The uniform tin hydroxide layers with a thickness of ~74 nm may be synthesized under pH = 2 conditions. By the electron microscopy method the average particle size was established changing from 200 to 400 nm for as-synthesized films, to ~20 nm for annealed which indicates the nanostructure nature of the films. The morphology, elemental composition and conductive properties of deposited films were investigated before and after heating stage. Studying the annealing temperature influence at the film resistance were identified a three temperature ranges within which the films sharply differ in their conductive properties, which is associated with phase and structural transformations in them. Shown, that the most conductive SnO2 films with the omic resistance 3-5 kOm/sm were obtained at the temperature range 620-870 K.

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MICROSTRUCTURE AND MAGNETIC PROPERTIES OF Sm2Fe17NNx−ALLOY- POWDERS AND OF BONDED ANISOTROPIC MAGNETS

International Journal of Modern Physics B ◽

10.1142/s0217979293001505 ◽

1993 ◽

Vol 07 (01n03) ◽

pp. 716-720

Author(s):

B. WALL ◽

M. KATTER ◽

W. RODEWALD ◽

M. VELICESCU

Keyword(s):

Solid Solution ◽

Particle Size ◽

Magnetic Properties ◽

Average Particle Size ◽

Average Particle ◽

Interstitial Solid Solution ◽

Demagnetization Curve ◽

Microstructure And Magnetic Properties

In cast Sm2Fe17 ingots minor fractions of SmFe2 and SmFe3 may occur. Nitrogenation of such alloy-powders inidicates that only Sm2Fe17 forms an interstitial solid solution whereas SmFe2 and SmFe3 decompose directly into SmN and α-Fe. From Sm2Fe17Nx alloy powders with an average particle size of about 3 μm anisotropic magnets were prepared by adding 15 wt% Zn-powder. Annealing at 390 ºC results in intrinsic coercivities > 15 kOe promoted by the formation of an unknown binary Fe8Zn92-compound. Whereas annealing at temperatures > 420 ºC leads to the formation of binary Fe3Zn7 and ternary Sm2FeZn2. By the formation of Sm2FeZn2 from Sm2Fe17Nx+Zn some α-Fe occurs inducing a step in the demagnetization curve J(H).

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Synthesis of Nanostructured Magnetic Mixed-Oxide Ferrite Powders by Using A Novel Chemical Method

MRS Proceedings ◽

10.1557/proc-720-h3.3 ◽

2002 ◽

Vol 720 ◽

Author(s):

N N Ghosh

Keyword(s):

Particle Size ◽

Mixed Oxide ◽

Chemical Method ◽

Average Particle Size ◽

Cost Effective ◽

Water Soluble ◽

Average Particle ◽

Chemical Route ◽

Water Soluble Polymer ◽

Different Temperatures

AbstractIn the present investigation, an attempt has been made to establish a new chemical route for synthesis of the nanostructured mixed oxide ferrite powders. By using this chemical method a variety of ferrite powders having spinel structure and doped with Co, Ni, Mn, Zn etc has been prepared. In this method nitrate salts of the different metals were used as starting materials. The aqueous solutions of the metal nitrates were mixed according to the molar ration of the compositions. Then the mixtures were mixed with an aqueous solution of water soluble polymer (polyvinyl alcohol). This mixture after drying yield fluffy brown powders. These powders were then calcined at different temperatures ranging from 400 °C to 700 °C. Nanostructured powders were obtained from the thermal decomposition of the brown powders. The powders, prepared by calcinations at different temperatures, were characterized by using X-Ray diffraction analysis, IR spectroscopy, TGA/DTA, and TEM. It was observed that the average particle size of the powders are in nanometer scale with a narrow size distribution. The average particle size of the powders was increased with the increase of calcinations temperature.This chemical method has proved to provide a convenient process for the preparation of nanostructured ceramic powders at comparatively low temperatures and offers the potential of being a simple and cost-effective route.

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Metallothermic Reduction at Low Temperature Synthesis of Ti4O7 Powder with Lithium Ion Insertion/Extraction Property

Materials Science Forum ◽

10.4028/www.scientific.net/msf.956.55 ◽

2019 ◽

Vol 956 ◽

pp. 55-66

Author(s):

Bei Lei Yan ◽

Wei Wei Meng ◽

San Chao Zhao

Keyword(s):

Reduction Method ◽

Average Particle Size ◽

Active Material ◽

Reduction Process ◽

Lithium Ion ◽

Thermal Reduction ◽

Average Particle ◽

X Ray Diffraction ◽

Metallothermic Reduction ◽

Extraction Property

In this work, a thermal reduction process via ultrafine titanium powder as the reducing agent under argon atmosphere is firstly used to prepare Ti4O7. Compared with the conventional method, this experiment process reduces the sintering temperature to 850°C. The phase transformation and the morphology of the as-prepared powders are examined by X-Ray diffraction (XRD) and scanning electron microscopy (SEM). Besides, it is found that the Ti4O7 powders obtained by titanium thermal reduction method exhibited the crystal structure, distinctly possessing an average particle size around 750 nm. The as-prepared Ti4O7 nanoparticles are used as anode active material in lithium battery. The results demonstrate that the anode with Ti4O7 calcined at 850°C by titanium thermal reduction method exhibited insertion/extraction lithium ion property.

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