The effects of magnetic field intensity on the magnetic properties of Fe80Si9B11 amorphous alloys during magnetic annealing

2021 ◽  
Vol 134 ◽  
pp. 107200
Author(s):  
Yin Zhang ◽  
Yong Yang ◽  
Zhongyuan Wu ◽  
Xiaomeng Feng ◽  
Chenxu Wang ◽  
...  
2019 ◽  
Vol 945 ◽  
pp. 653-659 ◽  
Author(s):  
E.A. Naumkin ◽  
J.N. Shermatov ◽  
A.I. Gaysina

One of the main reasons for the limited service life period of the reaction furnace coils is the carburization of the surface layers, which leads to a decrease in the performance characteristics of the pipe material, decrease in plasticity, generation of internal stresses, change in the metal structure. Therefore, monitoring the state of coils surface in order to detect critical parameters of the carburized layer thickness, using non-destructive methods of control is relevant. The results of the distribution of magnetic parameters over the depth of the carburized layer in the fragments of pipes made of steel 20Х25Н20C2, operated under furnace conditions at high temperatures, for 1300, 6000, 8000, 10000 hours are presented in the article. Analysis of the results showed that the magnetic properties are manifested only in the surface layers of the reaction furnace tubes. At the same time, the longer the service life period, the deeper is the layer exercising the magnetic properties and the higher in this layer the values ​of the constant magnetic field intensity. Analysis of magnetic properties distribution in all studied pipe fragments, both from the inner and from the outer side, showed the non-uniformity of the constant magnetic field intensity distribution, while zones of extremely high values ​are observed. The layer-by-layer surface removal in these zones with the determination of the resultant constant magnetic field intensity showed that there are critical values of the carburization depth, after which a sharp increase of this parameter is registered. These results can be used as a method for carburization depth determination, and also used to develop criterion for rejecting coils of reaction furnaces.


2012 ◽  
Vol 730-732 ◽  
pp. 117-122 ◽  
Author(s):  
Lucjan Kozielski ◽  
M. Płońska

For the growing interest in developing of more attractive multiferroic and magnetoelectric ceramics an alternative is a double-doped Pb(Zr1-xTix)O3- material with trivalent lanthanum and iron ions. Such material has a structure based on ABO3perovskite and properties depending on the chemical and structural composition. In the present work the results of the preparation and characterization of Fe3+- modified 9/65/35 PLZT ceramics have been reported. Two samples of Pb0,91(La1-zFez)0,09(Zr0,65Ti0,35)0,9775O3ceramics, for different Fe ions concentration (z = 0,0 and 0,5 at.%), were prepared from the MOM derived powders and sintered by the hot uniaxial pressing methods. To analyze the obtained ceramics properties the XRD, SEM and also application oriented dielectric and magnetic measurements were performed. The Fe3+substitution at the La-site of PLZT has shown many interesting and unusual dielectric, piezoelectric and magnetic properties. The obtained material was proposed to implement into Piezoelectric Transformer structure to change gain characteristics proportionally to magnetic field intensity.


2021 ◽  
Vol 11 (15) ◽  
pp. 6974
Author(s):  
Andrea Atrei ◽  
Fariba Fahmideh Mahdizadeh ◽  
Maria Camilla Baratto ◽  
Andrea Scala

The size, size distribution and magnetic properties of magnetite nanoparticles (NPs) prepared by co-precipitation without citrate, in the presence of citrate and citrate adsorbed post-synthesis were studied by X-ray Diffraction (XRD), Dynamic Light Scattering (DLS), Electron Paramagnetic Resonance (EPR) and magnetization measurements. The aim of this investigation was to clarify the effect of citrate ions on the size and magnetic properties of magnetite NPs. The size of the primary NPs, as determined by analysing the width of diffraction peaks using various methods, was ca. 10 nm for bare magnetite NPs and with citrate adsorbed post-synthesis, whereas it was around 5 nm for the NPs co-precipitated in the presence of citrate. DLS measurements show that the three types of NPs form aggregates (100–200 nm in diameter) but the dispersions of the citrate-coated NPs are more stable against sedimentation than those of bare NPs. The sizes and size distributions determined by XRD are in good agreement with those of the magnetic domains obtained by fitting of the magnetization vs. magnetic field intensity curves. Magnetization vs. magnetic field intensity curves show that the three kinds of sample are superparamagnetic.


2008 ◽  
Vol 8 (3) ◽  
pp. 501-507 ◽  
Author(s):  
G. Prattes ◽  
K. Schwingenschuh ◽  
H. U. Eichelberger ◽  
W. Magnes ◽  
M. Boudjada ◽  
...  

Abstract. We present the results of ground-based Ultra Low Frequency (ULF) magnetic field measurements observed from June to August 2004 during the Bovec earthquake on 12 July 2004. Further we give information about the seismic activity in the local observatory region for an extended time span 2004 and 2005. ULF magnetic field data are provided by the South European Geomagnetic Array (SEGMA) where the experience and heritage from the CHInese MAGnetometer (CHIMAG) fluxgate magnetometer comes to application. The intensities of the horizontal H and vertical Z magnetic field and the polarization ratio R of the vertical and horizontal magnetic field intensity are analyzed taking into consideration three SEGMA observatories located at different close distances and directions from the earthquake epicenter. We observed a significant increase of high polarization ratios during strong seismic activity at the observatory nearest to the Bovec earthquake epicenter. Apart from indirect ionospheric effects electromagnetic noise could be emitted in the lithosphere due to tectonic effects in the earthquake focus region causing anomalies of the vertical magnetic field intensity. Assuming that the measured vertical magnetic field intensities are of lithospheric origin, we roughly estimate the amplitude of electromagnetic noise in the Earths crust considering an average electrical conductivity of <σ>=10−3 S/m and a certain distance of the observatory to the earthquake epicenter.


Author(s):  
Pushap Lata Sharma ◽  
Sumit Gupta

This paper deals with the convection of micropolar fluids heated and soluted from below in the presence of suspended particles (fine dust) and uniform vertical rotation and uniform vertical magnetic field in a porous medium. Using the Boussinesq approximation, the linearized stability theory and normal mode analysis, the exact solutions are obtained for the case of two free boundaries. It is found that the presence of the suspended particles number density, the rotation parameter, stable solute, magnetic field intensity and medium permeability bring oscillatory modes which were non–existent in their absence. It is found that the presence of coupling between thermal and micropolar effects, rotation parameter, solute parameter and suspended particles may introduce overstability in the system. Graphs have been plotted by giving numerical values to the parameters accounting for rotation parameter , magnetic field solute parameter, the dynamic microrotation viscosity and coefficient of angular viscosity to depict the stability characteristics, for both the cases of stationary convection and overstability. It is found that Rayleigh number for the case of overstability and stationary convection increases with increase in rotation parameter, as well as with magnetic field intensity, solute parameter and decreases with increase in micropolar coefficients and medium permeability, for a fixed wave number, implying thereby the stabilizing effect of rotation parameter, magnetic field intensity ,solute parameter and destabilizing effect of micropolar coefficients and medium permeability on the thermosolutal convection of micropolar fluids.


2019 ◽  
Vol 7 (13) ◽  
pp. 3740-3743 ◽  
Author(s):  
Ying Li ◽  
Yue Long ◽  
Guoqiang Yang ◽  
Chen-Ho Tung ◽  
Kai Song

The wavelength of amplified spontaneous emission based on liquid magnetically responsive photonic crystals can be tuned by simply changing the magnetic field intensity.


Sign in / Sign up

Export Citation Format

Share Document