scholarly journals Impact of Ion Irradiation upon Structure and Magnetic Properties of NANOPERM-Type Amorphous and Nanocrystalline Alloys

2015 ◽  
Vol 2015 ◽  
pp. 1-19 ◽  
Author(s):  
Marcel Miglierini ◽  
Mariusz Hasiak
Keyword(s):  
Magnetic Properties ◽  
Ion Irradiation ◽  
Thermal Contact ◽  
Hysteresis Loops ◽  
Active Regions ◽  
Structural Rearrangement ◽  
Magnetic Interactions ◽  
Structural Modifications ◽  
Good Thermal Contact ◽  
Cooling Conditions

Structural modifications and their impact upon magnetic properties are studied in amorphous and nanocrystalline NANOPERM-type57Fe75Mo8Cu1B16alloy. They are introduced by irradiation with 130 keV N+ions to the total fluencies of up to 2.5 × 1017 ions/cm2under different cooling conditions. Increased temperature during the irradiation triggers formation of nanocrystallites of bcc-Fe in those subsurface regions that are affected by bombarding ions. No crystallization occurs when good thermal contact between the irradiated sample and a sample holder is assured. Instead, structural rearrangement which favours development of magnetically active regions was determined by the local probe methods of Mössbauer spectrometry. Dipole magnetic interactions dominate in subsurface regions on that side of the ribbons which was exposed to ion irradiation. Nevertheless, structural modifications demonstrate themselves also via macroscopic magnetic parameters such as temperature dependence of magnetization, Curie temperature, and hysteresis loops. Impact of only the temperature itself to the observed effects is assessed by the help of samples that were subjected just to heat treatment, that is, without ion irradiation.

Correlation of Cooling Conditions with the Shape of Hysteresis Loops in Air Cooled and Quenched Axis Shaft

2015 ◽  
Vol 644 ◽  
pp. 223-226
Author(s):  
Angelos Tsoutsias
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Magnetic Properties ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Cooling Conditions ◽  
Magnetic Hysteresis Loops ◽  
Nondestructive Characterization ◽  
Scanning Electron

The present paper investigates the utilization of the magnetic hysteresis loops for the nondestructive characterization of annealed axis shaft samples. The resulting magnetic properties were further evaluated by examining the microstructure of the annealed samples by using scanning electron microscopy.

scholarly journals Quantitative mapping of magnetic properties at the nanoscale with bimodal AFM

Nanoscale ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 2026-2033
Author(s):  
Victor G. Gisbert ◽  
Carlos A. Amo ◽  
Miriam Jaafar ◽  
Agustina Asenjo ◽  
Ricardo Garcia
Keyword(s):  
Magnetic Properties ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Magnetic Interactions ◽  
Quantitative Mapping ◽  
Quantitative Accuracy

We demonstrate that a force microscope operated in a bimodal configuration enables the mapping of magnetic interactions with high quantitative accuracy and high-spatial resolution (∼30 nm).

scholarly journals Tunable magnetization steps in mixed valent ferromagnet Eu2CoMnO6

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nara Lee ◽  
Jong Hyuk Kim ◽  
Dong Gun Oh ◽  
Hyun Jun Shin ◽  
Hwan Young Choi ◽  
...  
Keyword(s):  
Material Processing ◽  
Magnetic Properties ◽  
Single Crystals ◽  
Magnetic State ◽  
Hysteresis Loops ◽  
Double Perovskite ◽  
Processing Parameters ◽  
Perovskite Oxides ◽  
Efficient Approach ◽  
Isothermal Magnetization

AbstractMagnetic properties can be manipulated to enhance certain functionalities by tuning different material processing parameters. Here, we present the controllable magnetization steps of hysteresis loops in double-perovskite single crystals of Eu2CoMnO6. Ferromagnetic order emerges below TC ≈ 122 K along the crystallographic c axis. The difficulty in altering Co2+ and Mn4+ ions naturally induces additional antiferromagnetic clusters in this system. Annealing the crystals in different gas environments modifies the mixed magnetic state, and results in the retardation (after O2-annealing) and bifurcation (after Ar-annealing) of the magnetization steps of isothermal magnetization. This remarkable variation offers an efficient approach for improving the magnetic properties of double-perovskite oxides.

scholarly journals Effects of swift heavy ion-irradiation on magnetic properties of Co-doped TiO2

AIP Advances ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 025037
Author(s):  
S. R. Kumar ◽  
D. M. Phase ◽  
Ajay Gupta ◽  
A. C. Pandey ◽  
Ratnesh Gupta
Keyword(s):  
Magnetic Properties ◽  
Ion Irradiation ◽  
Heavy Ion ◽  
Swift Heavy Ion Irradiation ◽  
Doped Tio2 ◽  
Heavy Ion Irradiation ◽  
Swift Heavy Ion ◽  
Co Doped

Microstructure of Rapidly Solidified Cu-Fe Alloys

1983 ◽  
Vol 28 ◽  
Author(s):  
Uwe Köster ◽  
Christoph Caesar
Keyword(s):  
Cross Sections ◽  
Contact Surface ◽  
Iron Content ◽  
Melt Spinning ◽  
Volume Fraction ◽  
Thermal Contact ◽  
Lattice Parameter ◽  
Good Thermal Contact ◽  
Fe Alloys ◽  
Rapidly Solidified

ABSTRACTRapidly solidified ribbons of Cu-Fe alloys with iron contents up to 20 at.−% have been prepared by melt-spinning. Optical and electron microscopy as well as x-ray and electron diffraction techniques were used to characterize quantitatively the microstructure, i.e., grain size and shape, solubility of iron, lattice parameter, volume fraction and distribution of precipitated iron-particles, etc.Whereas the free surfaces of melt-spun Cu-Fe ribbons have been found to be very smooth, the contact surfaces usually consist of isolated areas of good thermal contact with small equiaxed grains separated by bands without contact during casting and therefore poor heat transfer. The cross sections of the ribbons generally exhibit a strong anisotropy in their microstructure: very fine crystals adjacent to the contact surface develop into narrow columnar grains, generally significantly elongated and extending across the whole section. The average columnar width of the grains has been found to decrease significantly with increasing iron content. Precipitation of iron not only depends on the iron content but also on the distance from the contact surface.

scholarly journals Crystal chemistry and single-phase synthesis of Gd3+substituted Co–Zn ferrite nanoparticles for enhanced magnetic properties

RSC Advances ◽  
2018 ◽  
Vol 8 (44) ◽  
pp. 25258-25267 ◽  
Author(s):  
R. A. Pawar ◽  
Sunil M. Patange ◽  
A. R. Shitre ◽  
S. K. Gore ◽  
S. S. Jadhav ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Crystal Chemistry ◽  
Single Phase ◽  
Secondary Phase ◽  
Ferrite Nanoparticles ◽  
Magnetic Interactions ◽  
Phase Synthesis ◽  
Zn Ferrite ◽  
Properties Of Materials

Rare earth (RE) ions are known to improve the magnetic interactions in spinel ferrites if they are accommodated in the lattice, whereas the formation of a secondary phase leads to the degradation of the magnetic properties of materials.

scholarly journals Optimization of Magnetic Properties of Magnetic Microwires by Post-Processing

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 1006
Author(s):  
Valentina Zhukova ◽  
Paula Corte-Leon ◽  
Lorena González-Legarreta ◽  
Ahmed Talaat ◽  
Juan Maria Blanco ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Chemical Composition ◽  
Hysteresis Loops ◽  
Structural Features ◽  
Post Processing ◽  
Soft Magnetic ◽  
Magnetic Microwires ◽  
Prepared State ◽  
Induced Magnetic Anisotropy ◽  
Selection Of

The influence of post-processing conditions on the magnetic properties of amorphous and nanocrystalline microwires has been thoroughly analyzed, paying attention to the influence of magnetoelastic, induced and magnetocrystalline anisotropies on the hysteresis loops of Fe-, Ni-, and Co-rich microwires. We showed that magnetic properties of glass-coated microwires can be tuned by the selection of appropriate chemical composition and geometry in as-prepared state or further considerably modified by appropriate post-processing, which consists of either annealing or glass-coated removal. Furthermore, stress-annealing or Joule heating can further effectively modify the magnetic properties of amorphous magnetic microwires owing to induced magnetic anisotropy. Devitrification of microwires can be useful for either magnetic softening or magnetic hardening of the microwires. Depending on the chemical composition of the metallic nucleus and on structural features (grain size, precipitating phases), nanocrystalline microwires can exhibit either soft magnetic properties or semi-hard magnetic properties. We demonstrated that the microwires with coercivities from 1 A/m to 40 kA/m can be prepared.

scholarly journals Radiation Effects in Amorphous Metallic Alloys as Revealed by Mössbauer Spectrometry: Part II. Ion Irradiation

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1309
Author(s):  
Marcel Miglierini
Keyword(s):  
Heavy Ions ◽  
Radiation Effects ◽  
Ion Irradiation ◽  
Active Regions ◽  
Mössbauer Spectrometry ◽  
Metallic Alloys ◽  
Conversion Electrons ◽  
Amorphous Metallic Alloys ◽  
Mossbauer Spectrometry ◽  
Light Ions

Due to their excellent magnetic properties, amorphous metallic alloys (AMAs) are considered for the construction of magnetic cores of radio-frequency cavities in accelerators. Here, they might be exposed to ion bombardment. The influence of irradiation by both light and heavy ions featuring low and high energies, respectively, is followed by the techniques of 57Fe Mössbauer spectrometry. Modifications of surface layers in selected Fe-containing AMAs after ion irradiation are unveiled by detection of conversion electrons and photons of characteristic radiation whereas those in their bulk are derived from standard transmission spectra. Rearrangement of microstructure which favors the formation of magnetically active regions, is observed in surface regions bombarded by light ions. Heavy ions caused pronounced effects in the orientation of net magnetization of the irradiated samples. No measurable impact upon short-range order arrangement was observed. Part I of this paper is devoted to radiation effects in Fe-based AMAs induced by neutron irradiation.

scholarly journals Developing a reference material set for the magnetic properties of NdFeB alloy-based hard magnetic materials

2019 ◽  
Vol 15 (1) ◽  
pp. 21-27
Author(s):  
E. A. Volegova ◽  
T. I. Maslova ◽  
V. O. Vas’kovskiy ◽  
A. S. Volegov
Keyword(s):  
Magnetic Properties ◽  
Magnetic Materials ◽  
Permanent Magnets ◽  
Magnetic Loss ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Magnetic Hysteresis Loop ◽  
Magnetic Characteristics ◽  
Hard Magnetic Materials ◽  
Certified Values

Introduction The introduction indicates the need for the use of permanent magnets in various technology fields. The necessity of measuring the limit magnetic hysteresis loop for the correct calculation of magnetic system parameters is considered. The main sources of error when measuring boundary hysteresis loops are given. The practical impossibility of verifying blocks of magnetic measuring systems element-by-element is noted. This paper is devoted to the development of reference materials (RMs) for the magnetic properties of hard magnetic materials based on Nd2Fe14B, a highly anisotropic intermetallic compound.Materials and measuring methods Nd-Fe-B permanent magnets were selected as the material for developing the RMs. RM certified values were established using a CYCLE‑3 apparatus included in the GET 198‑2017 State Primary Measurement Standard for units of magnetic loss power, magnetic induction of constant magnetic field in a range from 0.1 to 2.5 T and magnetic flux in a range from 1·10–5 to 3·10–2 Wb.Results and its discussion Based on the experimentally obtained boundary hysteresis loops, the magnetic characteristics were evaluated, the interval of permitted certified values was set, the measurement result uncertainty of certified values was estimated, the RM validity period was established and the first RM batch was released.Conclusion On the basis of conducted studies, the RM type for magnetic properties of NdFeB alloy-based hard magnetic materials was approved (MS NdFeB set). The developed RM set was registered under the numbers GSO 11059–2018 / GSO 11062–2018 in the State RM Register of the Russian Federation.

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