scholarly journals Enhancing the Magnetization, Dielectric Loss and Photocatalytic Activity of Co-cu Ferrite Nanoparticles Via the Substitution of Rare Earth Ions

2021 ◽  
Author(s):  
M.A. Abdo ◽  
S.F. Mansour ◽  
Faten Al-Hazmi ◽  
M.S. AlHammad ◽  
M.S. Sadeq
Keyword(s):  
Saturation Magnetization ◽  
Chemical Elements ◽  
Microwave Frequency ◽  
Lattice Parameter ◽  
Anisotropy Constant ◽  
Ferrite Nanoparticles ◽  
Rare Earth Ions ◽  
Suitable Candidate ◽  
The Impact ◽  
Complete Investigation

Abstract This study reports the impact of lanthanum substituted Co-Cu ferrite nanoparticles on the RhB dye disposal. Moreover, a complete investigation for the structural, magnetic and optical properties for Co0.5Cu0.5LaxFe2-xO4 (CCL) nanoferrites was executed. These nanocrystals synthesized via a combustion approach with a peculiar lattice parameter behavior; which discussed through three hypotheses. STEM-EDX micrographs of some selective samples confirm the nanocrystalline nature with presence of all constituents’ chemical elements CCL nanoferrites. The saturation magnetization of CCL nanoferrites was tuned with La3+ ions substitution. Contrary to the expected results, anisotropy constant introduced a decrement behavior with La/Fe substitution process. The microwave frequency (ωM) values for all CCL nanoparticles are in the range 11.87 GHz–9.46 GHz. The band gap has a peculiar behavior; a red shift and followed by a blue one. Through photodegradation testing, we explicate the RhB degradation mechanisms over our CCL nanoferrites. The nanoferrite Co0.5Cu0.5La0.15Fe1.85O4 has a moderate saturation magnetization, highest coercivity, and lowest loss which is a suitable candidate for data recording applications, furthermore can be utilized as a photocatalyst for RhB effluents removal with degradation efficiency 94.50% at 180 min solar radiation.

Elemental status of the adult able-bodied population of the Republic of Buryatia

2019 ◽  
pp. 308-313
Author(s):  
Inna Yu. Tarmaeva ◽  
Anatoliy V. Skalny ◽  
Olga G. Bogdanova ◽  
Andrey R. Grabeklis ◽  
Alexandr I. Belykh
Keyword(s):  
Inductively Coupled Plasma ◽  
Chemical Elements ◽  
Federal District ◽  
Significant Degree ◽  
Electrolyte Imbalance ◽  
Scientific Development ◽  
Inductively Coupled ◽  
Elemental Status ◽  
The Republic ◽  
The Impact

Introduction.The study of the elemental status of the population of individual regions of the Russian Federation with the purpose of scientific development and implementation of measures for elimination of revealed elementosis is a promising direction for preventive medicine.The aim of the studyis to study the elemental status of the adult able-bodied population of the Republic of Buryatia, which was part of the Siberian Federal district (SFD) until 2018.Materials and methods.The analysis was performed by inductively coupled plasma mass spectrometry (ICP-MS) on the basis of the accredited laboratory of “Center of biotic medicine”. (Moscow; ISO 9001: 2008 certificate 54Q10077 from 21.05.2010). The content of chemical elements in the hair of 130 adults (102 women and 28 men) aged 25–50 years was studied. This indicator serves as an indicator in assessing the impact of the environment on the human body. Methods of nonparametric statistics were used for mathematical processing of the data.Results.For women living in the Republic of Buryatia, the maximum values of Zn, increased levels of Cu, Li, Si were revealed; for men — the maximum values of Mg, Cr, Si, increased levels of P, Li, Se, V, Pb. Minimum values were found for P, Fe, V. Elemental status indicates a significant degree of prevalence of essential trace element deficiencies and electrolyte imbalance. The obtained data can be used as reference values for the content of chemical elements in the hair of adults living in the Republic of Buryatia.Conclusions:Elemental analysis of the population of the Republic of Buryatia indicates imbalances among the adult working-age population.

Structural, Morphological and Magnetic Characterization of Sm-substituted Ni-Zn Ferrite

2020 ◽  
Vol 10 (2) ◽  
pp. 152-156 ◽  
Author(s):  
Muhammad Hanif bin Zahari ◽  
Beh Hoe Guan ◽  
Lee Kean Chuan ◽  
Afiq Azri bin Zainudin
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Saturation Magnetization ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Rare Earth Ions ◽  
Ion Concentration ◽  
Zn Ferrite ◽  
Auto Combustion ◽  
Combustion Technique

Background: Rare earth materials are known for its salient electrical insulation properties with high values of electrical resistivity. It is expected that the substitution of rare earth ions into spinel ferrites could significantly alter its magnetic properties. In this work, the effect of the addition of Samarium ions on the structural, morphological and magnetic properties of Ni0.5Zn0.5SmxFe2-xO4 (x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) synthesized using sol-gel auto combustion technique was investigated. Methods: A series of Samarium-substituted Ni-Zn ferrite nanoparticles (Ni0.5Zn0.5SmxFe2-xO4 where x=0.00, 0.02, 0.04, 0.06, 0.08, 0.10) were synthesized by sol-gel auto-combustion technique. Structural, morphological and magnetic properties of the samples were examined through X-Ray Diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM) measurements. Results: XRD patterns revealed single-phased samples with spinel cubic structure up to x= 0.04. The average crystallite size of the samples varied in the range of 41.8 – 85.6 nm. The prepared samples exhibited agglomerated particles with larger grain size observed in Sm-substituted Ni-Zn ferrite as compared to the unsubstituted sample. The prepared samples exhibited typical soft magnetic behavior as evidenced by the small coercivity field. The magnetic saturation, Ms values decreased as the Sm3+ concentration increases. Conclusion: The substituted Ni-Zn ferrites form agglomerated particles inching towards more uniform microstructure with each increase in Sm3+ substitution. The saturation magnetization of substituted samples decreases with the increase of samarium ion concentration. The decrease in saturation magnetization can be explained based on weak super exchange interaction between A and B sites. The difference in magnetic properties between the samples despite the slight difference in Sm3+ concentrations suggests that the properties of the NiZnFe2O4 can be ‘tuned’, depending on the present need, through the substitution of Fe3+ with rare earth ions.

scholarly journals Characteristics of Cr-B Coatings Produced on Vanadis® 6 Tool Steel Using Laser Processing

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2621
Author(s):  
Aneta Bartkowska
Keyword(s):  
Corrosion Resistance ◽  
Tool Steel ◽  
Laser Processing ◽  
Chemical Elements ◽  
Steel Substrate ◽  
Processing Parameters ◽  
Beam Power ◽  
Laser Beam Power ◽  
High Microhardness ◽  
The Impact

The paper presents the results of a study of the microstructure, chemical composition, microhardness and corrosion resistance of Cr-B coatings produced on Vanadis 6 tool steel. In this study, chromium and boron were added to the steel surface using a laser alloying process. The main purpose of the study was to determine the impact of those chemical elements on surface properties. Chromium and boron as well as their mixtures were prepared in various proportions and then were applied on steel substrate in the form of precoat of 100 µm thickness. Depending on the type of precoat used and laser processing parameters, changes in microstructure and properties were observed. Coatings produced using precoat containing chromium and boron mixture were characterized by high microhardness (900 HV0.05–1300 HV0.005) while maintaining good corrosion resistance. It was also found that too low laser beam power contributed to the formation of cracks and porosity.

scholarly journals Specific Absorption Rate Dependency on the Co2+ Distribution and Magnetic Properties in CoxMn1-xFe2O4 Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1231
Author(s):  
Venkatesha Narayanaswamy ◽  
Imaddin A. Al-Omari ◽  
Aleksandr S. Kamzin ◽  
Bashar Issa ◽  
Huseyin O. Tekin ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Field Strength ◽  
Saturation Magnetization ◽  
Absorption Rate ◽  
Specific Absorption Rate ◽  
Ferrite Nanoparticles ◽  
Cofe2o4 Nanoparticles ◽  
Specific Absorption ◽  
Octahedral Sites ◽  
Mixed Ferrite

Mixed ferrite nanoparticles with compositions CoxMn1-xFe2O4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were synthesized by a simple chemical co-precipitation method. The structure and morphology of the nanoparticles were obtained by X-ray diffraction (XRD), transmission electron microscope (TEM), Raman spectroscopy, and Mössbauer spectroscopy. The average crystallite sizes decreased with increasing x, starting with 34.9 ± 0.6 nm for MnFe2O4 (x = 0) and ending with 15.0 ± 0.3 nm for CoFe2O4 (x = 1.0). TEM images show an edge morphology with the majority of the particles having cubic geometry and wide size distributions. The mixed ferrite and CoFe2O4 nanoparticles have an inverse spinel structure indicated by the splitting of A1g peak at around 620 cm−1 in Raman spectra. The intensity ratios of the A1g(1) and A1g(2) peaks indicate significant redistribution of Co2+ and Fe3+ cations among tetrahedral and octahedral sites in the mixed ferrite nanoparticles. Magnetic hysterics loops show that all the particles possess significant remnant magnetization and coercivity at room temperature. The mass-normalized saturation magnetization is highest for the composition with x = 0.8 (67.63 emu/g), while CoFe2O4 has a value of 65.19 emu/g. The nanoparticles were PEG (poly ethylene glycol) coated and examined for the magneto thermic heating ability using alternating magnetic field. Heating profiles with frequencies of 333.45, 349.20, 390.15, 491.10, 634.45, and 765.95 kHz and 200, 250, 300, and 350 G field amplitudes were obtained. The composition with x = 0.2 (Co0.2Mn0.8Fe2O4) with saturation magnetization 57.41 emu/g shows the highest specific absorption rate (SAR) value of 190.61 W/g for 10 mg/mL water dispersions at a frequency of 765.95 kHz and 350 G field strength. The SAR values for the mixed ferrite and CoFe2O4 nanoparticles increase with increasing concentration of particle dispersions, whereas for MnFe2O4, nanoparticles decrease with increasing the concentration of particle dispersions. SARs obtained for Co0.2Mn0.8Fe2O4 and CoFe2O4 nanoparticles fixed in agar ferrogel dispersions at frequency of 765.95 kHz and 350 G field strength are 140.35 and 67.60 W/g, respectively. This study shows the importance of optimizing the occupancy of Co2+ among tetrahedral and octahedral sites of the spinel system, concentration of the magnetic nanoparticle dispersions, and viscosity of the surrounding medium on the magnetic properties and heating efficiencies.

The impact of early smelting on the environment of Huoshiliang in Hexi Corridor, NW China, as recorded by fossil charcoal and chemical elements

2011 ◽  
Vol 305 (1-4) ◽  
pp. 329-336 ◽  
Author(s):  
Xiaoqiang Li ◽  
Nan Sun ◽  
John Dodson ◽  
Ming Ji ◽  
Keliang Zhao ◽  
...  
Keyword(s):  
Chemical Elements ◽  
Hexi Corridor ◽  
Nw China ◽  
The Impact

On the impact of lattice parameter accuracy of atomistic simulations on the microstructure of Ni-Ti shape memory alloys

2021 ◽  
Author(s):  
Lorenzo La Rosa ◽  
Francesco Maresca
Keyword(s):  
Molecular Dynamics ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Lattice Parameter ◽  
Lattice Parameters ◽  
Atomistic Simulations ◽  
Interatomic Potentials ◽  
The Impact

Abstract Ni-Ti is a key shape memory alloy (SMA) system for applications, being cheap and having good mechanical properties. Recently, atomistic simulations of Ni-Ti SMAs have been used with the purpose of revealing the nano-scale mechanisms that control superelasticity and the shape memory effect, which is crucial to guide alloying or processing strategies to improve materials performance. These atomistic simulations are based on molecular dynamics modelling that relies on (empirical) interatomic potentials. These simulations must reproduce accurately the mechanism of martensitic transformation and the microstructure that it originates, since this controls both superelasticity and the shape memory effect. As demonstrated by the energy minimization theory of martensitic transformations [Ball, James (1987) Archive for Rational Mechanics and Analysis, 100:13], the microstructure of martensite depends on the lattice parameters of the austenite and the martensite phases. Here, we compute the bounds of possible microstructural variations based on the experimental variations/uncertainties in the lattice parameter measurements. We show that both density functional theory and molecular dynamics lattice parameters are typically outside the experimental range, and that seemingly small deviations from this range induce large deviations from the experimental bounds of the microstructural predictions, with notable cases where unphysical microstructures are predicted to form. Therefore, our work points to a strategy for benchmarking and selecting interatomic potentials for atomistic modelling of shape memory alloys, which is crucial to modelling the development of martensitic microstructures and their impact on the shape memory effect.

scholarly journals Structural and Magnetic Property of Cr3+ Substituted Cobalt Ferrite Nanomaterials Prepared by the Sol-Gel Method

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2095 ◽  
Author(s):  
Jinpei Lin ◽  
Jiaqi Zhang ◽  
Hao Sun ◽  
Qing Lin ◽  
Zeping Guo ◽  
...  
Keyword(s):  
Saturation Magnetization ◽  
Sol Gel ◽  
Combustion Method ◽  
Lattice Parameter ◽  
Cubic Phase ◽  
Cobalt Chromium ◽  
X Ray Diffraction ◽  
Chromium Doping ◽  
Auto Combustion ◽  
Cr Concentration

Cobalt-chromium ferrite, CoCrxFe2−xO4 (x = 0–1.2), has been synthesized by the sol-gel auto-combustion method. X-ray diffraction (XRD) indicates that samples calcined at 800 °C for 3 h were a single-cubic phase. The lattice parameter decreased with increasing Cr concentration. Scanning electron microscopy (SEM) confirmed that the sample powders were nanoparticles. It was confirmed from the room temperature Mössbauer spectra that transition from the ferrimagnetic state to the superparamagnetic state occurred with the doping of chromium. Both the saturation magnetization and the coercivity decreased with the chromium doping. With a higher annealing temperature, the saturation magnetization increased and the coercivity increased initially and then decreased for CoCr0.2Fe1.8O4.

scholarly journals Магнитная анизотропия игольчатых монокристаллических включений MnSb в матрице InSb

2021 ◽  
Vol 47 (10) ◽  
pp. 46
Author(s):  
А.И. Дмитриев ◽  
А.В. Кочура ◽  
С.Ф. Маренкин ◽  
E. Lahderanta ◽  
А.П. Кузьменко ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Single Crystal ◽  
Saturation Magnetization ◽  
Power Law ◽  
Anisotropy Constant ◽  
Temperature Range

The magnetic anisotropy of needle-like single-crystal MnSb inclusions in the InSb matrix was determined and studied in the temperature range 5 – 350 K. In granular InSb-MnSb samples a power-law dependence of the anisotropy constant K(T) on the saturation magnetization MS(T) is observed in the temperature range 5 – 350 K with an exponent n = 3.2 ± 0.4 in accordance with the theories developed by Akulov, Zener, and Callens.

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