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

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 410 ◽  
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.

scholarly journals Microwave solvothermal synthesis and characterization of manganese-doped ZnO nanoparticles

2016 ◽  
Vol 7 ◽  
pp. 721-732 ◽  
Author(s):  
Jacek Wojnarowicz ◽  
Roman Mukhovskyi ◽  
Elzbieta Pietrzykowska ◽  
Sylwia Kusnieruk ◽  
Jan Mizeracki ◽  
...  
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Solvothermal Synthesis ◽  
Web Application ◽  
Zinc Acetate Dihydrate ◽  
Average Particle Size ◽  
Average Particle ◽  
Sem Images

Mn-doped zinc oxide nanoparticles were prepared by using the microwave solvothermal synthesis (MSS) technique. The nanoparticles were produced from a solution of zinc acetate dihydrate and manganese(II) acetate tetrahydrate using ethylene glycol as solvent. The content of Mn2+ in Zn1− x Mn x O ranged from 1 to 25 mol %. The following properties of the nanostructures were investigated: skeleton density, specific surface area (SSA), phase purity (XRD), lattice parameters, dopant content, average particle size, crystallite size distribution, morphology. The average particle size of Zn1− x Mn x O was determined using Scherrer’s formula, the Nanopowder XRD Processor Demo web application and by converting the specific surface area results. X-ray diffraction of synthesized samples shows a single-phase wurtzite crystal structure of ZnO without any indication of additional phases. Spherical Zn1− x Mn x O particles were obtained with monocrystalline structure and average particle sizes from 17 to 30 nm depending on the content of dopant. SEM images showed an impact of the dopant concentration on the morphology of the nanoparticles.

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

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.  

scholarly journals Structural and optical studies of TiO2:Ag2O nanocomposite by sol-gel method

2020 ◽  
Vol 38 (2) ◽  
pp. 263-270
Author(s):  
Vaibhav Koutu ◽  
Rajesh Dhakar ◽  
Pragya Ojha ◽  
Lokesh Shastri ◽  
M.M. Malik
Keyword(s):  
Particle Size ◽  
Crystallite Size ◽  
Sol Gel ◽  
Average Particle Size ◽  
Average Crystallite Size ◽  
Wide Band ◽  
Spectroscopic Studies ◽  
Memory Storage ◽  
Average Particle ◽  
Vis Spectroscopy

AbstractAs TiO2 is suitable for electronic and electrical applications, in the present work the authors have successfully modified TiO2 by adding silver (Ag) to form titanium oxide-silver oxide (TiO2:Ag2O) nanocomposite samples by using sol-gel technique. Characterizations of these composites have been performed using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and UV-Vis spectroscopy. XRD study revealed that the crystal structure of the samples consisted of tetragonal and cubic phases. This study further showed an increment in the average crystallite size from 8 nm to 38 nm with an increase in Ag concentration. The increase in crystallite size has been confirmed additionally by SEM and AFM. The increment in the average particle size of the samples may be attributed to an increase in silver molarity in the TiO2 matrix. Significant red shift in the absorption edge has been observed, causing reduction in the energy bandgap of the composites from 3.89 eV to 3.46 eV with an increase in particle size which is evident from UV-Vis spectroscopic studies. This wide-band gap properties of the TiO2:Ag2O nanocomposite make it suitable for memory-storage devices and dielectric applications.

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

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1097
Author(s):  
Luran Zhang ◽  
Xinchen Du ◽  
Hongjie Lu ◽  
Dandan Gao ◽  
Huan Liu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Annealing Temperature ◽  
Reduction Method ◽  
Solid Phase ◽  
Average Particle Size ◽  
Fept Nanoparticles ◽  
Average Particle ◽  
Phase Reduction ◽  
Different Temperatures ◽  
One Step

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.

scholarly journals Photoluminescences properties of lanthanum-silver co-doped ZnO nano particles

2018 ◽  
Vol 4 (4) ◽  
pp. 135-141 ◽  
Author(s):  
V. Porkalai ◽  
B. Sathya ◽  
D. Benny Anburaj ◽  
G Nedunchezhian ◽  
S. Joshua Gnanamuthu ◽  
...  
Keyword(s):  
Zno Nanoparticles ◽  
Zinc Acetate Dihydrate ◽  
Average Particle Size ◽  
Semiconductor Nanoparticles ◽  
Nano Particles ◽  
Average Particle ◽  
Rare Earth Ion ◽  
X Ray ◽  
Doped Zno ◽  
Co Doped

Recently, transition metal (TM) and rare earth ion doped II–VI semiconductor nanoparticles have received much attention because such doping can modify and improve optical properties of II–VI semiconductor nanoparticles by large amount. In this study, undoped, La doped and La+Ag co-doped ZnO nano particles have been successfully synthesized by sol-gel method using the mixture of Zinc acetate dihydrate and ethanol solution. The powders were calcinated at 600 °C for 2 h. The effect of lanthanum and lanthanum-silver incorporation on the structure, morphology, optical and electrical conductivity were examined by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Absorption (EDAX), Fourier transform infrared spectroscopy (FTIR), UV and Photo Luminescence (PL) Characterization. The average particle size of the synthesized ZnO nanoparticles is calculated using the Scherrer formula and is found to be of less than 20 nm. Luminescences properties were found to be enhanced for the La and La+Ag co-doped ZnO nanoparticles.

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

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).

Synthesis of Fe2O3/C Nanocomposite Using Microwave Assisted Calcination Method

2014 ◽  
Vol 896 ◽  
pp. 100-103 ◽  
Author(s):  
Anggi Puspita Swardhani ◽  
Ferry Iskandar ◽  
Abdullah Mikrajuddin ◽  
Khairurrijal
Keyword(s):  
Crystallite Size ◽  
Average Particle Size ◽  
Molar Ratio ◽  
Average Particle ◽  
X Ray ◽  
Molar Ratios ◽  
Microwave Assisted ◽  
Chloride Hexahydrate ◽  
Calcination Method ◽  
Scherrer Method

Fe2O3/C nanocomposites were successfully synthesized using microwave assisted calcination method. Ferric (III) chloride hexahydrate (FeCl36H2O), sodium hydroxide (NaOH), and dextrose monohydrate (C6H12O6H2O) were used as precursors. A microwave oven of 2.445 GHz with a power of 600 W for 20 minutes was employed during the syntheses. Calcination was performed in a simple furnace at 350 °C for 30 min. The molar ratio of C:Fe is the only process parameter. From Scanning Electron Microscope images, the average particle size were 199 nm and 74 nm for the samples with molar ratio of C:Fe of 1:2 and 1:1, respectively. X-ray diffractometer spectra showed that the obtained samples have γ-Fe2O3 (maghemite) crystal structure. Using the Scherrer method, the crystallite size were 61.7, 58.8, 52.5, and 48.8 nm for the samples with the molar ratios of C:Fe of 1:3, 1:2, 1:1, and 2:1, respectively. It means that the crystallite size of the nanocomposite decreases with the increase of the molar ratio of carbon to iron (C:Fe). The Brunauer-Emmett-Teller characterization showed that the surface area as high as 255.6 m2/g is achieved by of the Fe2O3/C nanocomposite with the molar ratio of C:Fe of 1:1.

Synthesis of Gamma-Alumina Nanopowders Using Waste Metal Aluminum and Stability Surfactants

2019 ◽  
Vol 19 (02) ◽  
pp. 1950014
Author(s):  
Sabereh Nazari ◽  
Sadegh Nazari ◽  
Fariba Mansourizadeh ◽  
Gholamreza Karimi
Keyword(s):  
Particle Size ◽  
Polyethylene Glycol ◽  
Polyvinyl Alcohol ◽  
Specific Surface ◽  
Pore Volume ◽  
Average Particle Size ◽  
Average Crystallite Size ◽  
Average Particle ◽  
Gamma Alumina ◽  
Metal Aluminum

In this study, high purity gamma-alumina nanopowders with crystalline structures have been prepared via a sol–gel process by waste metal aluminum, HCl, NaOH, Polyethylene glycol (PEG) and polyvinyl alcohol (PVA). Polyethylene glycol and polyvinyl alcohol have been used as stabilizing agents. The characterization of the samples has been performed utilizing XRD, FTIR, SEM, N2 adsorption/desorption techniques. Prepared samples of gamma-alumina at 800∘C with PEG has an average crystallite size of 2.58[Formula: see text]nm, average particle size of 21[Formula: see text]nm, specific surface area (SSA) of 65.55[Formula: see text]m2/g, and pore volume of [Formula: see text]0.06[Formula: see text]cm3/g. The average crystallite size of 3.07[Formula: see text]nm, average particle size of 31[Formula: see text]nm, specific surface area of 131.25[Formula: see text]m2/g, and pore volume of [Formula: see text]0.14[Formula: see text]cm3/g, were obtained using PVA surfactant.

Magnetic Properties of the La0.50Ba0.50MnO3 Nanomanganites

2009 ◽  
Vol 152-153 ◽  
pp. 135-138 ◽  
Author(s):  
S.V. Trukhanov ◽  
A.V. Trukhanov ◽  
Christian E. Botez ◽  
H. Szymczak
Keyword(s):  
Magnetic Properties ◽  
Crystallite Size ◽  
Sol Gel ◽  
Exchange Interactions ◽  
Average Crystallite Size ◽  
Anomalous Behavior ◽  
Air Atmosphere ◽  
Crystallite Surface ◽  
Step Heat Treatment ◽  
Lattice Compression

Nanocrystalline La0.50Ba0.50MnO3 manganite was synthesized by an optimized sol-gel method. The initial sample was subjected to step-by-step heat treatment under air atmosphere. The ion stoichiometry, the morphology of crystallites of ceramics, and the magnetic properties were studied. It is established that the average crystallite size increases with increasing annealing temperature. All of the samples studied are characterized by a perovskite-like cubic structure, with the unit cell parameter a increasing continuously with the average crystallite size. The most significant lattice compression occurs in the sample with an average crystallite size of ~ 30 nm. The increase in the average crystallite size causes a nonmonotonic increase in the Curie temperature and in the spontaneous magnetic moment. The anomalous behavior of the magnetic properties of the La0.50Ba0.50MnO3 manganites obtained is explained by the competition between two size effects, namely, the frustration of the indirect exchange interactions Mn3+ – O – Mn4+ on the nanocrystallite surface and the crystal lattice compression due to the crystallite surface tension.

Sign in / Sign up

Export Citation Format

Share Document