scholarly journals Влияние режимов измельчения порошковых материалов (Sm,Ho)-=SUB=-2-=/SUB=-Fe-=SUB=-17-=/SUB=-N-=SUB=-x-=/SUB=- (x=0; 2.4) на их структуру и магнитные свойства

2020 ◽  
Vol 90 (7) ◽  
pp. 1159
Author(s):  
С.В. Веселова ◽  
И.С. Терёшина ◽  
В.Н. Вербецкий ◽  
А.Ю. Карпенков ◽  
А.Г. Савченко
Keyword(s):  
Permanent Magnets ◽  
Magnetic Hysteresis ◽  
High Energy ◽  
Partial Substitution ◽  
Magnetic Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Topology ◽  
Powder Samples ◽  
Composition Structure

The composition, structure, topology of the surface of a cast, homogenized, and nitrogenated alloy based on the Sm2Fe17 intermetallic compound by Ho substitution for Sm have been investigated by means of X-ray fluorescence, X-ray diffraction, and scanning electron microscopy using BSE/EDS detectors. Magnetic properties are presented for initial Sm1.2Но0.8Fe17 compound, Sm1.2Но0.8Fe17N2.4 nitride and its milled powders. It has been established that the partial substitution of Sm by Ho in the rare-earth sublattice in combination with the effect of introduction of nitrogen into the lattice of initial compound lead to an increase of such magnetic characteristics as specific magnetization and coercive force. Comparative analysis of the magnetic hysteresis properties of powder samples showed that an increase of the milling time Sm-Ho-Fe-N powders using high-energy ball milling (15, 30, 45 and 60 min) improves the main magnetic characteristics. The functional characteristics of Sm-Ho-Fe-N powders prepared by milling are an important for the development of new high-coercive permanent magnets based on them.

scholarly journals Effect of alloying elements (Zr, Hf, Co), heat and mechanical treatment conditions on the phase composition and magnetic properties of SmFe11Ti compounds with ThMn12 structure

2018 ◽  
Vol 185 ◽  
pp. 04026 ◽  
Author(s):  
Andrey Urzhumtsev ◽  
Maksim Anikin ◽  
Evgeniy Tarasov ◽  
Mikhail Semkin ◽  
Maksim Cherepkov ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Mechanical Treatment ◽  
Annealing Temperature ◽  
Magnetic Hysteresis ◽  
High Energy ◽  
Magnetic Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Treatment Conditions ◽  
Hysteresis Properties

The results of thermomagnetic, metallographic and X-ray diffraction phase analysis as well as the measurements of specific magnetization (σs), Curie temperature (TC), coercive force (HC) of (Sm,M)(Fe,M)12-xTix alloys samples, where M = Zr, Hf, Co with the ThMn12 main phase structure (1-12) are presented. The effect of the annealing temperature and the cooling rate on the formation of 1-12 phase and its magnetic properties, including the effect of high-energy milling on the magnetic hysteresis properties and alloys structure are described. It was found that the highest magnetic characteristics such as σs = 112.6 emu/g and TC = 600 ºC are attained in the (Sm0.8Zr0.2)(Fe0.75Co0.25)11.4Ti0.6 alloy after its annealing at 1050 °C and rapid cooling. It is noted that a mechanical milling of the alloy leads to 1-12 phase amorphization which accompanied by an α-(Fe) or metal Co phases impurity formation.

scholarly journals Study of the effect of nitrogen and hydrogen on the structure and magnetic properties of (Sm, Er)2Fe17 alloys

2021 ◽  
Vol 2103 (1) ◽  
pp. 012073
Author(s):  
I S Tereshina ◽  
S V Veselova ◽  
O V Akimova ◽  
M A Paukov ◽  
A Yu Karpenkov ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Permanent Magnets ◽  
Magnetic Hysteresis ◽  
Partial Substitution ◽  
Pulsed Magnetic Fields ◽  
Mechanical Grinding ◽  
Static Magnetic Fields ◽  
X Ray ◽  
Powder Samples ◽  
Grinding Time

Abstract Materials based on the Sm2Fe17 compound with nitrogen have great potential for the manufacture of highly efficient permanent magnets. The initial, nitrided, and hydrogenated alloys based on the Sm2Fe17 intermetallic compound with partial substitution of erbium atoms for samarium atoms Sm1.2Er0.8Fe17(H, N)x have been studied by X-ray phase analysis and scanning electron microscopy. Nanopowders of Sm1.2Er0.8Fe17N2 were obtained by mechanical grinding. The grinding time was varied from 0 to 60 minutes. The magnetic hysteresis properties of all powder samples were studied in static magnetic fields up to 7 T, as well as in pulsed magnetic fields up to 60 T. The strength of the intersublattice exchange interaction was estimated. The obtained values λ are valid only for the explored concentration of Sm/Er ions.

scholarly journals Mn-Induced Thermal Stability of L10 Phase in Fept Magnetic Nanoscale Ribbons

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1278
Author(s):  
Alina Daniela Crisan ◽  
Aurel Leca ◽  
Dan Pantelica ◽  
Ioan Dan ◽  
Ovidiu Crisan
Keyword(s):  
Rare Earth ◽  
Single Phase ◽  
Permanent Magnets ◽  
Magnetic Hysteresis ◽  
Ternary Alloys ◽  
Large Temperature ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Operation Conditions

Magnetic nanoscale materials exhibiting the L10 tetragonal phase such as FePt or ternary alloys derived from FePt show most promising magnetic properties as a novel class of rare earth free permanent magnets with high operating temperature. A granular alloy derived from binary FePt with low Pt content and the addition of Mn with the nominal composition Fe57Mn8Pt35 has been synthesized in the shape of melt-spun ribbons and subsequently annealed at 600 °C and 700 °C for promoting the formation of single phase, L10 tetragonal, hard magnetic phase. Proton-induced X-ray emission spectroscopy PIXE has been utilized for checking the compositional effect of Mn addition. Structural properties were analyzed using X-ray diffraction and diffractograms were analyzed using full profile Rietveld-type analysis with MAUD (Materials Analysis Using Diffraction) software. By using temperature-dependent synchrotron X-ray diffraction, the disorder–order phase transformation and the stability of the hard magnetic L10 phase were monitored over a large temperature range (50–800 °C). A large interval of structural stability of the L10 phase was observed and this stability was interpreted in terms of higher ordering of the L10 phase promoted by the Mn addition. It was moreover found that both crystal growth and unit cell expansion are inhibited, up to the highest temperature investigated (800 °C), proving thus that the Mn addition stabilizes the formed L10 structure further. Magnetic hysteresis loops confirmed structural data, revealing a strong coercive field for a sample wherein single phase, hard, magnetic tetragonal L10 exists. These findings open good perspectives for use as nanocomposite, rare earth free magnets, working in extreme operation conditions.

X-Ray Diffraction Analysis of Mechanically Milled Alumina and Zirconia Powders

2017 ◽  
Vol 17 ◽  
pp. 96-100 ◽  
Author(s):  
S. Renold Elsen ◽  
K. Jegadeesan ◽  
J. Ronald Aseer
Keyword(s):  
Particle Size ◽  
Ball Milling ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Samples ◽  
Alumina Composite ◽  
Energy Ball ◽  
Zirconia Toughened Alumina ◽  
Zirconia Powders

Ball milling is one of the top down approach used for reducing the particle size of bulk powder. Especially high energy ball milling is done to reduce the particle size to nanodomain. The Zirconia Toughened Alumina nanocomposite has diverged application in different engineering fields. The alumina and zirconia powders used for fabrication of Zirconia Toughened Alumina composite are subjected for ball milling. The effect of ball milling on the powders is reported on the work. The characterisation of the powder samples were done by X-ray diffraction. This was done to evaluate the effect of the starting material on the final product. Using the Scherer’s formula, Williamson-Hall analysis the change in crystallite size and strain were analysed.

Epitaxial Growth of Atomically Flat Spin Dependent Tunneling Junctions

1999 ◽  
Vol 570 ◽  
Author(s):  
Y. Li ◽  
S. X. Wang ◽  
F. B. Mancoff ◽  
B. M. Clemens
Keyword(s):  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
High Energy ◽  
High Energy Electron ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Tunneling Junctions ◽  
Atomically Flat

ABSTRACTSpin dependent tunneling junctions with epitaxially grown underlayers have been investigated to examine the possibility of achieving very flat and uniform barrier layers. Pt/Ni80Fe20 /Fe50Mn50/Ni80Fe20layers were deposited on sapphire (0001) substrates at different temperatures and monitored by in-situ reflection high energy electron diffraction (RHEED). The surface morphology has been found to depend strongly on the growth temperature. X-ray diffraction and magnetic hysteresis loop measurements were also performed to characterize the film structures

Characterizations of Synthetic 8mol% YSZ with Comparison to 3mol %YSZ for HT-SOFC

2020 ◽  
Vol 38 (4A) ◽  
pp. 491-500
Author(s):  
Abeer F. Al-Attar ◽  
Saad B. H. Farid ◽  
Fadhil A. Hashim
Keyword(s):  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Structural Information ◽  
Impedance Analysis ◽  
High Energy ◽  
Yttria Stabilized Zirconia ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Powder Morphology ◽  
X Ray

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol% yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling to synthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolyte for high temperature solid oxide fuel cells (HT-SOFC). This work aims to evaluate the densification and ionic conductivity of the sintered electrolytes at 1650°C. The bulk density was measured according to ASTM C373-17. The powder morphology and the microstructure of the sintered electrolytes were analyzed via Field Emission Scanning Electron Microscopy (FESEM). The chemical analysis was obtained with Energy-dispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) was used to obtain structural information of the starting materials and the sintered electrolytes. The ionic conductivity was obtained through electrochemical impedance spectroscopy (EIS) in the air as a function of temperatures at a frequency range of 100(mHz)-100(kHz). It is found that the 3YSZ has a higher density than the 8YSZ. The impedance analysis showed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906 (S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a lower activation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, the prepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.

Sign in / Sign up

Export Citation Format

Share Document