Green synthesis of superparamagnetic magnetite nanoparticles: effect of natural surfactant and heat treatment on the magnetic properties

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.

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Effect of heat treatment on ac and dc magnetic properties of high permeability soft magnetic alloys 1J85

Procedia Engineering ◽

10.1016/j.proeng.2011.12.501 ◽

2012 ◽

Vol 27 ◽

pp. 652-657

Author(s):

Chenghui Lei ◽

Bing Wang ◽

Yue Chen

Keyword(s):

Heat Treatment ◽

Magnetic Properties ◽

High Permeability ◽

Soft Magnetic ◽

Magnetic Alloys ◽

Soft Magnetic Alloys

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Magnetic properties of doped Mn-Ga alloys made by mechanical milling and heat treatment

AIP Advances ◽

10.1063/1.4943931 ◽

2016 ◽

Vol 6 (5) ◽

pp. 056012 ◽

Cited By ~ 3

Author(s):

Daniel R. Brown ◽

Ke Han ◽

Theo Siegrist ◽

Tiglet Besara ◽

Rongmei Niu

Keyword(s):

Heat Treatment ◽

Magnetic Properties ◽

Mechanical Milling

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Magnetic Properties, Nanostructure, and Ordering Kinetics of Nb Additive FePtCu Films

Materials Science Forum ◽

10.4028/www.scientific.net/msf.638-642.1743 ◽

2010 ◽

Vol 638-642 ◽

pp. 1743-1748

Author(s):

G.J. Chen ◽

Y.H. Shih ◽

Jason S.C. Jang ◽

S.R. Jian ◽

P.H. Tsai ◽

...

Keyword(s):

Heat Treatment ◽

Activation Energy ◽

Magnetic Properties ◽

Heating Rates ◽

Fept Alloy ◽

Ordering Kinetics ◽

Nb Content ◽

Kinetics Of ◽

Nb Addition ◽

Microstructure And Magnetic Properties

In this study,the (FePt)94-xCu6Nbx (x=0, 2.87, 4.52, 5.67) alloy films were prepared by co-sputtering. The effects of Nb addition content and heat treatment on the microstructure and magnetic properties of the polycrystalline FePtCu films are reported. Our previous experiments showed that the ordering temperature of the (FePt)94Cu6 films reduced to 320 °C, which is much lower than that of the FePt alloy. However, the grain growth after heat treatment limited the practical application in recording media. By adding the Nb content in the (FePt)94Cu6 film, the grain sizes of the films can be adjusted from 50 to 18nm, even for the films annealed at temperature as high as 600°C. DSC traces of as-deposited disorder films at different heating rates, to evaluate the crystallization of the order phase, revealed that the addition of Nb enhanced the activation energy of ordering from 87 kJ/mol to 288 kJ/mol for the (FePt)94-xCu6Nbx (x=0 and 2.87, respectively) films. The reduction of the grain size and the corresponding increase in the activation energy of the Fe-Pt-Cu-Nb films might result from the precipitation of the Nb atoms around the ordering FePt phase. The (FePt)94-xCu6Nbx (x=2.87) film showed a coercive force of 13.4 kOe and the magnetization of 687 emu/cc.

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The Effect of Aging on Precipitates, Mechanical and Magnetic Properties of Fe-21Cr-15Ni-6Mn-Nb Low Magnetic Stainless Steel

Metals ◽

10.3390/met11050819 ◽

2021 ◽

Vol 11 (5) ◽

pp. 819

Author(s):

Changsheng Li ◽

Kun Li ◽

Jingbo Dong ◽

Jinyi Ren ◽

Yanlei Song

Keyword(s):

Heat Treatment ◽

Tensile Strength ◽

Stainless Steel ◽

Magnetic Properties ◽

Solution Heat Treatment ◽

Aging Treatment ◽

Relative Magnetic Permeability ◽

Coarsening Behavior ◽

The Matrix ◽

Coherent Orientation

The effect of aging on the precipitates, mechanical and magnetic properties of Fe-21Cr-15Ni-6Mn-Nb low magnetic stainless steel were investigated. The steel was aged at 550–750 °C for 2 h after solution heat treatment at 1100 °C for 1 h. During the aging treatment, the (Nb, V)(C, N) particles gradually precipitated in the grain, which were coherent or semi-coherent with the matrix. When the aging temperature was beyond 650 °C, the coarsening rate of (Nb, V)(C, N) particles increase rapidly and the coherent orientation between (Nb, V)(C, N) particles and the matrix was lost gradually. Meanwhile, coarse M23C6 was distributed at the grain boundary with chain shape, which was non-coherent with the matrix. The coarsening behavior of (Nb, V)(C, N) precipitates in the grain was analyzed, and the size of the particles precipitated after aging treatment at 650°C for different time was calculated and studied. After aging treatment at 650 °C for 2 h, the yield strength and tensile strength of the stainless steel was 705.6 MPa and 1002.3 MPa, the elongation and the relative magnetic permeability was 37.8% and 1.0035, respectively.

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