Effect of Secondary Decomposition on Coercivity of Fe-Co-Cr Alloys with 15% Co

2015 ◽  
Vol 233-234 ◽  
pp. 623-628 ◽  
Author(s):  
Vladimir P. Menushenkov ◽  
Vladimir S. Shubakov
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Coercive Force ◽  
Volume Fraction ◽  
Magnetic Measurements ◽  
Magnetic Treatment ◽  
Magnetic Insulation ◽  
Transmission Electron ◽  
Microstructure And Magnetic Properties

The microstructure and magnetic properties of Fe-Co-Cr alloys with 15 wt % Co were investigated using transmission electron microscopy and magnetic measurements. The secondary decomposition within both the α2-phase matrix and the α1-phase particles was observed for magnets subjected thermo-magnetic treatment and subsequent stepped aging or continuous-cooling treatments. During high-temperature treatments (630-600оC), when the α2phase is dominant (the volume fraction is more than 50%), the secondary decomposition of this phase takes place (α2→ α1'+ α2'). The deterioration of magnetic insulation of α1-phase particles results in the decrease in the coercive force of alloys. Below 600оC, when the α1phase is dominant (the volume fraction is more than 50%), the splitting of elongated α1-phase particles occurs. When the temperature of stepped-aging decreases in high steps, the secondary decomposition (α1→ α1'+ α2') leads to the splitting of initial α1-phase particles into fine slightly elongated particles and the decrease in the coercive force.

Study of Structural, Optical, Dielectric and Magnetic Properties of Zinc Ferrite Synthesized by Co-Precipitation

2017 ◽  
Vol 17 ◽  
pp. 1-9
Author(s):  
P. Annie Vinosha ◽  
L. Ansel Mely ◽  
J. Emima Jeronsia ◽  
F. Heartlin Monica ◽  
K. Raja ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Zinc Ferrite ◽  
Magnetic Measurements ◽  
Functional Dependence ◽  
Spectral Studies ◽  
Dielectric Studies ◽  
Transmission Electron ◽  
Co Precipitation

Spinel zinc ferrite (ZnFe2O4) nanoparticles have engrossed immense attention due to its unusual amalgamation of its properties especially the magnetic properties and these properties are catered as fitting candidates in the field of electronics. Nanostructured spinel zinc ferrite particles were synthesized using scalable co-precipitation technique. The morphology, particle size and reaction pace of the nanoparticles (NPs) were fine tuned by eco-friendly technique. These NPs were characterized by UV-Visible spectroscopy (UV-Vis), photoluminescence (PL), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Transmission electron microscopy (TEM), vibrating sample magnetometer ((VSM) and Dielectric studies. The required profiles were confirmed by XRD and FTIR spectra, UV-Vis, PL spectral studies. Further these measurements divulge the significance of optical properties and the spectral parameters are used to appraise the optical constants required for fabrication. Transmission electron microscopy eventually discloses the morphological analysis of the synthesized ZnFe2O4 nanoparticle as 15 nm within the scaling limitations. Using, VSM, the magnetic behaviour of the material have been determined as a function of magnetic field at ambient temperature; the magnetic measurements well-establishes the magnetic property and disclosed to have weak ferromagnetic behaviour as the crystallite size decreases. The A.C. conductivity measurements and dielectric studies were done as a functional dependence of frequency and temperature on synthesized nanoparticles.

TEM Study and Magnetic Measurements of Nano–Scale Particles Formed in Cu–Base Alloys

2010 ◽  
Vol 89-91 ◽  
pp. 757-762 ◽  
Author(s):  
Sung Kang ◽  
Teppei Muramatsu ◽  
Mahoto Takeda
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Phase Transformation ◽  
Magnetic Measurements ◽  
Precipitation Behavior ◽  
Nano Scale ◽  
Transmission Electron ◽  
Means Of Transmission

The precipitation behavior of nano–scale particles formed in Cu–base alloys was studied by means of transmission electron microscopy (TEM) and SQUID measurements. Linear arrangements of two or more nano–scale particles cubic in shape were observed in the <100> orientations of matrices in a Cu–Co alloy. Although the trend was less explicit in a Cu–Fe alloy, Fe precipitates accompanying twin–like lattice modulations were found in the decomposition, when no deformation was applied. The present SQUID measurements revealed several significant influences to magnetic properties were induced during the precipitation in Cu–base alloys. Lorentz electron microscopy confirmed that phase transformation from γ → α occurred at the stage that the Fe particles reach to 40~60nm in size.

Formation of bismuth iron oxide based core–shell structures and their dielectric, ferroelectric and magnetic properties

2019 ◽  
Vol 7 (5) ◽  
pp. 1280-1291 ◽  
Author(s):  
Alaka Panda ◽  
R. Govindaraj ◽  
R. Mythili ◽  
G. Amarendra
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Magnetic Properties ◽  
Iron Oxide ◽  
Shell Structures ◽  
Core Shell ◽  
Bismuth Iron Oxide ◽  
The Core ◽  
Shell Nanostructures ◽  
Transmission Electron

Bismuth and iron oxides subjected to ball milling followed by controlled annealing treatments showed the formation of core–shell nanostructures with Bi2Fe4O9 as the core and a shell of BiFeO3 and Bi25FeO40 phases as deduced based on the analysis of transmission electron microscopy results.

The influence of Pt and SrTiO3 interlayers on the microstructure of PbTiO3 thin films deposited by laser ablation on (001) MgO

1995 ◽  
Vol 10 (4) ◽  
pp. 791-794 ◽  
Author(s):  
S. Stemmer ◽  
S.K. Streiffer ◽  
W-Y. Hsu ◽  
F. Ernst ◽  
R. Raj ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Laser Ablation ◽  
Volume Fraction ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Transmission Electron ◽  
Electrical Conductivities ◽  
Different Types ◽  
Oriented Material

We have used conventional and high-resolution transmission electron microscopy to investigate the microstruture of epitaxial, ferroelectric PbTiO3 films grown by pulsed laser ablation on (001) MgO single crystals, and on MgO covered with epitaxial Pt or SrTiO3. Pronounced variations are found in the widths and lengths of a-axis-oriented domains in these films, although the volume fraction of a-axis-oriented material varies only weakly for the different types of samples. In addition, the films deposited onto Pt-coated MgO have a larger grain size than those deposited onto bare MgO or SrTiO3/MgO. Possible reasons for the variations in the distribution of a-axis-oriented material in these samples include differences in the elastic properties and electrical conductivities of the different substrate combinations.

Preparation and Property of Al87Ce3Ni8.5Mn1.5 Nanophase Amorphous Composites

2011 ◽  
Vol 412 ◽  
pp. 263-266
Author(s):  
Hong Wei Zhang ◽  
Li Li Zhang ◽  
Feng Rui Zhai ◽  
Jia Jin Tian ◽  
Can Bang Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Phase ◽  
Volume Fraction ◽  
Material Structure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Different Temperatures

The higher mechanical strength of Al87Ce3Ni8.5Mn1.5 nanophase amorphous composites has been obtained with two methods. The first nanophase amorphous composites are directly produced by the single roller spin quenching technology. The method taken for the second nanophase amorphous composites is at first to obtain amorphous single-phase alloy, followed by annealed at different temperatures .The formative condition, the microstructure, the particle size, the volume fraction of α-Al phase and microhardness of nanophase amorphous composites etc have been investigated and compared by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The microstructure of composites produced by the second method is higher than the former, the fabricated material structure of the system is more uniform and the process is easier to control.

TEM Study of FePt and FePt:C/FePt Composite Double-Layered Thin Films

2013 ◽  
Vol 275-277 ◽  
pp. 1952-1955
Author(s):  
Ling Fang Jin ◽  
Xing Zhong Li
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Magnetic Properties ◽  
Composite Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

New functional nanocomposite FePt:C thin films with FePt underlayers were synthesized by noneptaxial growth. The effect of the FePt layer on the ordering, orientation and magnetic properties of the composite layer has been investigated by adjusting FePt underlayer thickness from 2 nm to 14 nm. Transmission electron microscopy (TEM), together with x-ray diffraction (XRD), has been used to check the growth of the double-layered films and to study the microstructure, including the grain size, shape, orientation and distribution. XRD scans reveal that the orientation of the films was dependent on FePt underlayer thickness. In this paper, the TEM studies of both single-layered nonepitaxially grown FePt and FePt:C composite L10 phase and double-layered deposition FePt:C/FePt are presented.

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