scholarly journals Reducing the ordering temperature of FePt nanoparticles by Cu additive and alternate reduction method

2017 ◽  
Vol 07 (06) ◽  
pp. 1750039
Author(s):  
Fang Wang ◽  
Xiaojun Bai
Keyword(s):  
Annealing Temperature ◽  
Reduction Method ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Metal Salts ◽  
Fept Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Cu Additive

(FePt)[Formula: see text]Cu[Formula: see text] nanoparticles were successfully prepared by alternate reduction of metal salts in aqueous medium. Detailed investigations on the correlation between the magnetic and structural properties of these nanoparticles are presented as a function of annealing temperature. Both the X-ray diffraction patterns and the magnetic hysteresis loop measurements show the existence of L10-FePt phase at a relative low annealing temperature. It is proved that the Cu additive and alternate reduction are very effective methods in reducing the ordering temperature of FePt nanoparticles.

Magnetic Properties of Manganese-Titanium Substituted Barium Ferrite Ba(TiMn)xFe12-2xO19(x=0.0, 0.5, 1.0, 1.5, 2.0) Prepared by the Molten Salt Method

2010 ◽  
Vol 434-435 ◽  
pp. 240-243 ◽  
Author(s):  
Hai Feng Li ◽  
Rong Zhou Gong ◽  
Hao Luo ◽  
Jun Zhou ◽  
Li Ren Fan ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Molten Salt ◽  
Barium Ferrite ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Electromagnetic Properties ◽  
Molten Salt Method ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
X Ray

M-type hexaferrites Ba(TiMn)xFe12-2xO19 (x=0 to 2) powders were synthesized by molten salt method. X-ray diffraction, scanning electron microscope and vibrating sample magnetometer were used to analyze the structures and electromagnetic properties. The results showed that, the magnetoplumbite structures for all samples were formed. Magnetic hysteresis loop measurements of the Ba(TiMn)xFe12-2xO19, exhibitted that the saturation magnetization (Ms), the remanent magnetization (Mr) and the coercitivity (Hc) of compounds depended strongly on the chemical composition of materials. The maxium values of Ms (52.68emu/g) and Mr (32.89emu/g) of the compounds were found at x=0.5; however, the values of Hc and the areas of magnetic hysteresis loop of compounds decreased with increasing the value of x. The Ba(TiMn)1.5Fe9O19/paraffin wax composites containing 40vol% of doped barium ferrite exhibitted good absorption performances in the frequency range of 2–14 GHz.

Influence of Zinc-Zirconium Substitution on Magnetic Properties of Ba(ZnZr)xFe12-2xO19 Hexaferrite Prepared by the Molten Salt Method

2009 ◽  
Vol 79-82 ◽  
pp. 2071-2074 ◽  
Author(s):  
Hai Feng Li ◽  
Rong Zhou Gong ◽  
Xian Wang ◽  
Li Ren Fan ◽  
Gang He ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Molten Salt ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Chemical Compositions ◽  
Molten Salt Method ◽  
Vibrating Sample Magnetometer ◽  
Hexagonal Ferrites ◽  
X Ray Diffraction ◽  
X Ray

M-type hexaferrites Ba(ZnZr)xFe12-2xO19 (x=0, 0.5, 1.0, 1.5) powders, have been synthesized by molten salt method, where x varies from 0 to 1.5 in steps of 0.5. X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer(VSM) were used to analyze the structures and magnetic properties. The results showed that, the magnetoplumbite structures for all samples calcining at 1100°C have been formed. The magnetic hysteresis loop measurements of the hexagonal ferrites powders showed that the saturation magnetization (Ms), the remanent magnetization (Mr), and the coercitivity (Hc) of ferrites depend strongly on the chemical compositions of materials. The data showed that the max Hc was obtained when substitution of x=1.0 (Hc=63.9 Oe), while the best Ms was obtained when substitution of x=0.5 (Ms=54.02 emu/g). Zn and Zr substitutions greatly modified the magnetic properties of BaM hexaferrite.

scholarly journals Influence of Laser Energy and Annealing on Structural and Optical Properties of CdS Films Prepared by Laser Induced Plasma

2020 ◽  
pp. 1307-1312
Author(s):  
Wadaa S. Hussein ◽  
Ala' Fadhil Ahmed ◽  
Kadhim A. Aadim
Keyword(s):  
Optical Properties ◽  
Annealing Temperature ◽  
Laser Energy ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
X Ray ◽  
Laser Induced Plasma ◽  
Visible Spectra ◽  
Uv Visible ◽  
Diffraction Patterns

The current study was achieved on the effects of laser energy and annealing temperature on x-ray structural and optical properties, such as the UV-Visible spectra of cadmium sulfide (CdS). The films were prepared using pules laser deposition technique (PLD) under vacuum at a pressure of 2.5×10-2 mbar with different laser energies (500-800 mJ) and annealing at a temperature of 473K. X-ray diffraction patterns and intensity curves for the CdS showed that the formation of CdS multi-crystallization films at all laser energies. The optical properties of the films were studied and the variables affecting them were investigated in relation to laser energy and changes in temperature.

Effects of Ba and Ti Codoping on Stoichiometric and Nonstoichiometric BiFeO3 Multiferroic Ceramics

2015 ◽  
Vol 815 ◽  
pp. 154-158 ◽  
Author(s):  
Xi Zhou ◽  
Yao Xiong ◽  
Yu Chong Pei ◽  
Wan Ping Chen
Keyword(s):  
Perovskite Phase ◽  
Magnetic Hysteresis ◽  
Low Frequency ◽  
Magnetic Hysteresis Loop ◽  
Solid State Reactions ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrical And Dielectric Properties ◽  
Loop Measurement

Bi0.9Ba0.1Fe0.95O3 and Bi0.9Ba0.1FexTi0.05O3 (x=0.95, 0.925, 0.90) ceramics were prepared through conventional solid state reactions. X-ray diffraction analyses indicated that a high content of perovskite phase was obtained for all the four compositions. While the three (Ba,Ti)-codoped compositions all showed a higher resistivity than Bi0.9Ba0.1Fe0.95O3, and Bi0.9Ba0.1Fe0.925Ti0.05O3 had the best electrical and dielectric properties among the three (Ba,Ti)-codoped compositions, including the largest dielectric constant, the smallest dielectric loss at low frequency range, and the highest electrical resistivity. Magnetic hysteresis loop measurement revealed that the four compositions had similarly enhanced magnetic properties. It is concluded that much attention should be paid to fine composition adjustment when multiple elements are co-doped to BiFeO3 system.

scholarly journals Effect of alloying elements (Zr, Hf, Co), heat and mechanical treatment conditions on the phase composition and magnetic properties of SmFe11Ti compounds with ThMn12 structure

2018 ◽  
Vol 185 ◽  
pp. 04026 ◽  
Author(s):  
Andrey Urzhumtsev ◽  
Maksim Anikin ◽  
Evgeniy Tarasov ◽  
Mikhail Semkin ◽  
Maksim Cherepkov ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Mechanical Treatment ◽  
Annealing Temperature ◽  
Magnetic Hysteresis ◽  
High Energy ◽  
Magnetic Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Treatment Conditions ◽  
Hysteresis Properties

The results of thermomagnetic, metallographic and X-ray diffraction phase analysis as well as the measurements of specific magnetization (σs), Curie temperature (TC), coercive force (HC) of (Sm,M)(Fe,M)12-xTix alloys samples, where M = Zr, Hf, Co with the ThMn12 main phase structure (1-12) are presented. The effect of the annealing temperature and the cooling rate on the formation of 1-12 phase and its magnetic properties, including the effect of high-energy milling on the magnetic hysteresis properties and alloys structure are described. It was found that the highest magnetic characteristics such as σs = 112.6 emu/g and TC = 600 ºC are attained in the (Sm0.8Zr0.2)(Fe0.75Co0.25)11.4Ti0.6 alloy after its annealing at 1050 °C and rapid cooling. It is noted that a mechanical milling of the alloy leads to 1-12 phase amorphization which accompanied by an α-(Fe) or metal Co phases impurity formation.

scholarly journals Morphological and magnetic features of columnar nanostructures CuO

2021 ◽  
Vol 2094 (2) ◽  
pp. 022002
Author(s):  
A V Ushakov ◽  
I V Karpov ◽  
L Yu Fedorov ◽  
V G Demin
Keyword(s):  
Magnetic Measurements ◽  
Magnetic Hysteresis ◽  
Coherent Scattering ◽  
Magnetic Hysteresis Loop ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Monoclinic Crystal Structure ◽  
Ionic Nature

Abstract Columnar nanostructures (CNS) were grown by plasma chemical synthesis at a gas mixture pressure of 90% He + 10% O2 200 Pa and substrate temperatures of 340K (sample 1) and 370K (sample 2). The effect of substrate temperature on the morphological, crystalline, magnetic, and impedance properties of CNS was studied. Scanning microscopy (SEM) showed that the morphology of CNS varies significantly from dendritic to wire structure. Energy dispersive X-ray spectroscopy (EDS) showed a change in the stoichiometry of the deficiency samples (Cu52O48) to an excess of oxygen (Cu42O58). X-ray diffraction analysis (XRD) and Rietveld fitting showed that samples 1 and 2 have a monoclinic crystal structure with a large proportion of the amorphous phase, the size of coherent scattering regions (CSR) was 26 nm (sample 1). Magnetic measurements showed that sample 1 exhibits ferromagnetic behavior, and at 6 K a magnetic hysteresis loop appears. Sample 2 from 250 K to room temperature exhibits diamagnetic behavior. A connection was found between the appearance of diamagnetism and a jump in the dielectric constant of sample 2. An assumption was made about the electron-ionic nature of the diamagnetism of sample 2.

scholarly journals CO CLUSTER FORMATION IN TiO2 DMS AND A METHOD OF ESTIMATION

2017 ◽  
Vol 24 (1&2) ◽  
pp. 199-204
Author(s):  
Le Van Hong ◽  
Nguyen Chi Thuan ◽  
Nguyen Van Dai ◽  
Nguyen Xuan Phuc
Keyword(s):  
Raman Scattering ◽  
Magnetic Moment ◽  
Annealing Temperature ◽  
Anatase Phase ◽  
Cluster Formation ◽  
Sol Gel ◽  
Magnetic Hysteresis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Magnetization

The paper presents experimental observations of the Co cluster formation in TiO2/Co powder samples prepared by the Sol-Gel method. The obtained X-ray diffraction patterns and Raman scattering show that the anatase phase of TiO2 was successfully synthesized at an annealing temperature of 450°C. Comprehensive studies by means of X-ray diffraction, Raman scattering, thermal magnetization in a temperature range of 300–1000 K and magnetic hysteresis at room temperature confirm that a part of Co did not substitute for Ti in TiO2 structure, otherwise it has reasonably formed cluster of Co in samples. Based on the thermal magnetization curves a method to estimate the magnetic moment per one Co ion substituted for Ti in TiO2 structure was proposed. By means of this method the volume of Co substituted for Ti has been estimated for samples annealed at various temperatures around 450°C. The obtained results show that the volume of Co cluster rises when the annealing temperature increases. This obtained result persuasively explains the large divergence in the magnetic moment per one Co ion reported in the most published papers. 

Epitaxial Growth of Atomically Flat Spin Dependent Tunneling Junctions

1999 ◽  
Vol 570 ◽  
Author(s):  
Y. Li ◽  
S. X. Wang ◽  
F. B. Mancoff ◽  
B. M. Clemens
Keyword(s):  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
High Energy ◽  
High Energy Electron ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Tunneling Junctions ◽  
Atomically Flat

ABSTRACTSpin dependent tunneling junctions with epitaxially grown underlayers have been investigated to examine the possibility of achieving very flat and uniform barrier layers. Pt/Ni80Fe20 /Fe50Mn50/Ni80Fe20layers were deposited on sapphire (0001) substrates at different temperatures and monitored by in-situ reflection high energy electron diffraction (RHEED). The surface morphology has been found to depend strongly on the growth temperature. X-ray diffraction and magnetic hysteresis loop measurements were also performed to characterize the film structures

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

Examination of Rabbit Fc Crystals

1968 ◽  
Vol 26 ◽  
pp. 140-141
Author(s):  
J. P. Robinson ◽  
P. G. Lenhert
Keyword(s):  
Molecular Weight ◽  
Flat Plate ◽  
Phosphate Buffer ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutral Ph ◽  
Small Crystals ◽  
Carbon Coated ◽  
Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

Sign in / Sign up

Export Citation Format

Share Document