scholarly journals Enhancement of anisotropy energy of SmCo5 by ceasing the coupling at 2c sites in the crystal lattice with Cu substitution

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Syed Kamran Haider ◽  
Hieu Minh Ngo ◽  
Dongsoo Kim ◽  
Young Soo Kang
Keyword(s):  
Crystal Lattice ◽  
Energy Efficient ◽  
Magnetic Particles ◽  
Anisotropy Energy ◽  
Ternary Alloys ◽  
Total Cost ◽  
Additional Weight ◽  
Cu Substitution ◽  
Decoupling Effect ◽  
Co Precipitation

AbstractSmCo5 and SmCo5−xCux magnetic particles were produced by co-precipitation followed by reduction diffusion. HRTEM confirmed the Cu substitution in the SmCo5 lattice. Non-magnetic Cu was substituted at “2c” site in the SmCo5 crystal lattice and effectively stopped the coupling in its surroundings. This decoupling effect decreased magnetic moment from SmCo5 (12.86 μB) to SmCo4Cu (10.58 μB) and SmCo3Cu2 (7.79 μB) and enhanced anisotropy energy from SmCo5 (10.87 Mega erg/cm3) to SmCo4Cu (14.05 Mega erg/cm3) and SmCo3Cu2 (14.78 Mega erg/cm3). Enhancement of the anisotropy energy increased the coercivity as its values for SmCo5, SmCo4Cu and SmCo3Cu2 were recorded as 4.5, 5.97 and 6.99 kOe respectively. Being six times cheaper as compared to Co, substituted Cu reduced the price of SmCo3Cu2 up to 2%. Extra 15% Co was added which not only enhanced the Mr value but also reduced the 5% of the total cost because of additional weight added to the SmCo3Cu2. Method reported in this work is most energy efficient method on the synthesis of Sm–Co–Cu ternary alloys until now.

Preparation of Magnetic Compositions of Diatomite

2013 ◽  
Vol 467 ◽  
pp. 97-102 ◽  
Author(s):  
Kuralay Beisenbaevna Korzhynbayeva ◽  
Sagdat Tazhibayeva ◽  
Kuanyshbek Bituovich Musabekov ◽  
Mukhametkali Musagalievich Mataev ◽  
Orynbay Yerbolatuli Zhanadilov
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Lattice ◽  
Magnetic Particle ◽  
Comprehensive Analysis ◽  
Co Precipitation

A new magnetitediatomite compositions was synthesized by co-precipitation diatomite with Fe2+ and Fe3+ in the presence of diatomite. Magnetic compositions of diatomite were investigated using XRD and SEM. Comprehensive analysis for SEM and XRD data shows that the most favorable magnetic particle including to the diatomite pores in DM-15 and DM-30. Increasing of content of maghemite in compositions causes reduction of the proportion of smectite and mica, which is associated with the destruction of the crystal lattice. Determined by the interaction between the diatomite surface and including particles of magnetite and maghemite can be hydrogen bonds between the SiOH and SiOH2+-groups of the diatomite surface and the iron (II) and iron (III) oxides.

scholarly journals Magnetically recyclable Ag/TiO2 co-decorated magnetic silica composite for photodegradation of dibutyl phthalate with fluorescent lamps

2020 ◽  
Vol 81 (4) ◽  
pp. 790-800
Author(s):  
Zhiqiang Ding ◽  
Yue Liu ◽  
Yong Fu ◽  
Feng Chen ◽  
Zhangpei Chen ◽  
...  
Keyword(s):  
Magnetic Particles ◽  
Dibutyl Phthalate ◽  
Degradation Process ◽  
Environmental Safety ◽  
Degradation Efficiency ◽  
Precipitation Method ◽  
Solution Ph ◽  
Fluorescent Lamps ◽  
Butyl Phthalate ◽  
Co Precipitation

Abstract In recent years, industrial contaminants and especially organic pollutions have been threatening both environmental safety and human health. Particularly, dibutyl phthalate (DBP) has been considered as one of the major hazardous contaminants due to its widespread production and ecological toxicities. Consequently, reliable methods toward the efficient and environmentally benign degradation of DBP in wastewater would be very desirable. To this end, a novel magnetically separable porous TiO2/Ag composite photocatalyst with magnetic Fe3O4 particles as the core was developed and successfully introduced to the photocatalytic degradation of DBP under visible irradiation with a fluorescent lamp. The presented work describes the grafting of Ag co-doped TiO2 composite on the silica-modified porous Fe3O4 magnetic particles with a simple and inexpensive chemical co-precipitation method. Through the investigation of the influencing factors including photocatalyst dosage, initial concentration of DBP, solution pH, and H2O2 content, we found that the degradation efficiency could reach 74%. The photodegradation recovery experiment showed that the degradation efficiency of this photocatalyst remained almost the same after five times of reuse. In addition, a plausible degradation process was also proposed involving the attack of active hydroxyl radicals generated from this photocatalysis system and production of the corresponding intermediates of butyl phthalate, diethyl phthalate, dipropyl phthalate, methyl benzoate, and benzoic acid.

Monodisperse AuCuSn trimetallic nanocube catalysts

2016 ◽  
Vol 52 (8) ◽  
pp. 1614-1617 ◽  
Author(s):  
Biplab K. Patra ◽  
Santimoy Khilari ◽  
Debabrata Pradhan ◽  
Narayan Pradhan
Keyword(s):  
Crystal Lattice ◽  
Co Precipitation

Monodisperse trimetallic AuCuSn nanocubes are reported where Sn and Cu are inserted into the crystal lattice following co-precipitation protocols along with Au.

Treatment of Dye Wastewater by Adsorption with Bentonite-Supported Magnetic Materials

2011 ◽  
Vol 340 ◽  
pp. 487-491
Author(s):  
Xiao Ming Chen ◽  
Jian Feng Ma ◽  
Ding Long Li
Keyword(s):  
Removal Efficiency ◽  
Contact Time ◽  
Magnetic Particles ◽  
Influence Factor ◽  
Dye Wastewater ◽  
No Adsorption ◽  
Initial Concentration ◽  
Magnetite Particles ◽  
Co Precipitation ◽  
Maximum Removal

Bentonite-supported magnetite particles (MagBt-p) were prepared by co-precipitation. The adsorption capacity of Bentonite-supported magnetic particles on waste water containing OrangeⅡ was tested. Some influence factor such as the dose, the initial concentration of OrangeⅡ, the pH, the contact time and the presence of surfactant were studied. Results showed that cation surfactant (CTAB) greatly enhanced the adsorption of OrangeⅡ. The maximum removal efficiency was 96.6% at 180mg/L (CTAB) and beyond this concentration there was almost no adsorption. Besides, the removal efficiency was affected by pH and contact time, the maximum removal efficiency was found at pH 2.1-3, the adsorption was rapid during the first 120 min and then equilibrium within 180min.

Biomimetic Magnetic Nanoparticles for Hyperthermia Treatment

2011 ◽  
Vol 493-494 ◽  
pp. 16-19
Author(s):  
E.M. Múzquiz-Ramos ◽  
Dora A. Cortés-Hernández ◽  
C.G. Sánchez-Torres ◽  
José C. Escobedo-Bocardo ◽  
A. Zugasti ◽  
...  
Keyword(s):  
Magnetic Particles ◽  
Sol Gel ◽  
Apatite Layer ◽  
Apatite Formation ◽  
Temperature Profiles ◽  
Osteosarcoma Cell ◽  
Hyperthermia Treatment ◽  
Before And After ◽  
Magnetite Particles ◽  
Co Precipitation

The aim of this work was the synthesis of bioactive magnetic particles (BMP) which are expected to form a thin apatite layer on its surface that may bond to bone with the osseous carcinogen tissue. Magnetite and Mg0.6Ca0.4Fe2O4 nanoparticles were obtained by a reverse co-precipitation and sol-gel methods, respectively. Magnetite particles were coated with chitosan in order to obtain a stable ferrofluid. Then both ferrites were biomimetically treated using two different simulated body fluids (SBF and 1.5 SBF). An apatite layer was formed on both types of BMP after the biomimetic treatment. Both ferrites showed superparamagnetic behavior before and after the apatite formation. Their time-dependent temperature profiles were measured under the effect of an AC magnetic field (AMF). After less than 20 min of applying the AMF an appropriate temperature for hyperthermia treatment was obtained. No citotoxicity was observed after osteosarcoma cell culture testing of BMP. Furthermore, after applying an AMF to the cells in contact with the BMP, the cells viability decreased considerably.

Synthesis of Superparamagnetic Nanoparticles for Desalination Purposes

2016 ◽  
Vol 856 ◽  
pp. 105-115
Author(s):  
E.D. Metaxa ◽  
K. Berkesi ◽  
D. Musmarra ◽  
Athanasios G. Mamalis ◽  
Evangelos Hristoforou
Keyword(s):  
Magnetic Particles ◽  
Water Solubility ◽  
Saline Water ◽  
Forward Osmosis ◽  
Analytical Techniques ◽  
Superparamagnetic Nanoparticles ◽  
Experimental Results ◽  
Original Form ◽  
Co Precipitation ◽  
Desalination Plants

The aim of this study is to describe the synthetic procedure of superparamagnetic nanoparticles of magnetite and maghemite and to use the magnetic merit of thesenano-sized ferrite particles coated byorganic substances having good water solubility to desalinate saline water. The idea derives from the experimental results of research groups using magnetic particles covered by polymers to increase the efficiency of membranes in forward osmosis desalination plants. The magnetic particles can beseparatedfrom water by an external magnet field easily.As magnetic particles, Fe3O4 can be prepared in different sizes from nanoto microscale by the help of co-precipitation or thermal decomposition techniques. These superparamagnetic nanoparticles are well-promising candidates for use in desalination purposes either from own or after their fabrication with polymer molecules, such as cyclodexrins, in their original form or in a modified one in order to enhance their water solubility, according to some preliminary experimental results found by our research team but not referred here. Herein, various inexpensive synthetic routes for superparamagnetic nanoparticles of magnetite (Fe3O4) and maghemite ( -Fe2O3) are described, as well as the characterization results of the produced nanoparticles with XRD, TEM, FT-IR, RAMAN, DFT and TGA/DTG analytical techniques are also referred.

Preparation of nano-sized magnetic particles from spent pickling liquors by ultrasonic-assisted chemical co-precipitation

2009 ◽  
Vol 163 (2-3) ◽  
pp. 1173-1178 ◽  
Author(s):  
Bing Tang ◽  
Liangjun Yuan ◽  
Taihong Shi ◽  
Linfeng Yu ◽  
Youchun Zhu
Keyword(s):  
Magnetic Particles ◽  
Ultrasonic Assisted ◽  
Co Precipitation

scholarly journals MAGNETIC NANOPARTICLES IN BIOCATALYSIS

2021 ◽  
pp. 66-72
Author(s):  
Александрина Михайловна Сульман ◽  
Ольга Валентиновна Гребенникова ◽  
Анастасия Евгеньевна Филатова
Keyword(s):  
Magnetic Nanoparticles ◽  
Horseradish Peroxidase ◽  
Kinetic Parameters ◽  
Magnetic Particles ◽  
Ph Value ◽  
Co Precipitation ◽  
Optimal Ph

В работе изучены свойства ферментативных систем на основе иммобилизованной на магнитные частицы пероксидазы корня хрена (HRP). Магнитные наночастицы FeO были синтезированы методом соосаждения. Затем на их поверхность двумя способами была иммобилизована пероксидаза корня хрена путем ковалентной сшивки. Для этого, в первом случае, FeO последовательно обрабатывали тетраэтоксисиланом, 3-аминопропилтриэтоксисиланом, глутаровым диальдегидом и HRP. Во втором, перед иммобилизацией HRP на поверхность носителя были последовательно нанесены 3-аминопропилтриэтоксисилан, глутаровым диальдегидом и HRP. Активность синтезированных биокатализаторов оценивалась спектрофотометрически в реакции окисления 2,2'-азино-бис(3-этилбензотиазолин-6-сульфонат) аммония пероксидом водорода. В работе также были рассчитаны кинетические параметры K и V для всех типов катализаторов, в том числе для нативной HRP. Среди всех биокаталитических систем лучшие значения, по сравнению с нативным ферментом (K = 4 ммоль/л и V = 12.6∙10, ммоль/л∙с) , были получены для первого типа биокатализатора (K = 5 ммоль/л и V = 2.5∙10, ммоль/л∙с). Было также определено, что оптимальным значением рН является 7.2. The synthesis of biocatalytic systems based on horseradish peroxidase immobilized on magnetic particles was investigated. The method of co-precipitation was used to obtain magnetic nanoparticles. Two types of magnetic particles were studied: untreated and pretreated with tetraethoxysilane. The basic kinetic parameters KM and Vm were calculated for all types of biocatalysts. The optimal pH value was determined for the biocatalyst that showed the greatest activity during oxidation

scholarly journals Synthesis and Characterization of Janus Magnetic Nanoparticles and its Application as an Adsorbent

2013 ◽  
Vol 27 ◽  
pp. 64-68 ◽  
Author(s):  
Zayed Bin Zakir Shawon
Keyword(s):  
Magnetic Nanoparticles ◽  
Magnetic Particles ◽  
Chemical Engineering ◽  
Pickering Emulsion ◽  
Quick Method ◽  
Coated Nanoparticles ◽  
Janus Nanoparticles ◽  
Nanoparticles Characterization ◽  
Co Precipitation

A simple and quick method to synthesize Janus magnetic particles in the nano-sized range was conducted. Magnetic nanoparticles (MNPs) with diameters in the range of 10-15 nm were prepared by the co-precipitation of Fe2+ and Fe3+ precursors under alkaline and inert condition. The Pickering Emulsion method was used for the immobilization of magnetic nanoparticles onto the surface of paraffin wax balls via water-molten wax emulsion. Silanization of the exposed side of the immobilized magnetic particles was carried out with APTES and the waxes were subsequently dissolved to obtain free Janus nanoparticles. Characterization tests such as TGA, SEM-EDX, TEM and FTIR were performed to ascertain the partial coating of the Janus nanoparticles. Moreover, adsorption capacity of the Janus nanoparticles on Hg2+ ions was found to be intermediate between those using the uncoated and fully coated nanoparticles indicating successful synthesis of Janus nanoparticles DOI: http://dx.doi.org/10.3329/jce.v27i1.15861 Journal of Chemical Engineering, IEB Vol. ChE. 27, No. 1, June 2012: 64-68

On the Development of a Piezoelectric-Actuated Compliant Brake Mechanism for Modular Robots

2011 ◽  
Author(s):  
Chris E. Thorne ◽  
Paul J. White ◽  
Mark Yim
Keyword(s):  
Energy Efficient ◽  
Magnetic Particles ◽  
Modular Robots ◽  
Modular Robotics ◽  
Dynamic Motion ◽  
Locking Mechanism ◽  
Design And Manufacturing ◽  
Reconfigurable Robot ◽  
Drum Brakes ◽  
Electromagnetically Actuated

A bistable brake mechanism can be beneficial to the development of an energy efficient module for a modular reconfigurable robot. These robots are comprised of many repeated units. To date, research efforts have focused on increasing specific torque to expand the capabilities of modular robots. In this work, we present the continued development of energy efficient joint-locking mechanisms, specifically a piezoelectric actuator and a compliant transmission. The design and manufacturing of the mechanism is presented along with a model for predicting the static and dynamic behavior of the device. We also present experimental results that indicate better performance in terms of power consumption, specific torque, and bandwidth than is possible with comparable devices that utilize magnetic particles and electromagnetically-actuated disc and drum brakes. When fully implemented, this joint-locking mechanism will lead to three critical improvements in the area of modular robotics: decreased energy expenditure per non-active module, increased ability to utilize dynamic motion due to less reliance on highly-geared servo motors, and improved ability to maintain configurations with high mechanical advantage.

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