The Effect of Dopants on Magnetic Properties of the Ordered Fe65-xAl35-yMx,y (Mx,y=Ga,B,V; X,Y=5,10) Alloys

2012 ◽  
Vol 190 ◽  
pp. 534-537
Author(s):  
E. Voronina ◽  
Eugene P. Yelsukov ◽  
A.V. Korolyov ◽  
H.H. Klauss ◽  
T. Dellmann ◽  
...  
Keyword(s):  
Magnetic State ◽  
Ac Susceptibility ◽  
Hysteresis Loops ◽  
Ternary Alloys ◽  
Magnetic Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Initial Alloy ◽  
Magnetic Filed ◽  
Magnetic States

The results of X-ray diffraction, complex in-field (up to 9 T) and temperature (5300 К) Mössbauer and magnetometric studies of the ordered Fe65Al35-хMх (M=Ga, B; x=0,5,10) and Fe65-хVxAl35 (x=5,10) alloys are presented. Analysis of the magnetometry studies shows that the systems Fe65Al35 и Fe65Al35-хGaх (x=5, 10) are characterized by two different magnetic states with essentially distinguishing hysteresis loops and AC susceptibility values. The temperature and external magnetic field values inducing the transition from one magnetic state to another are higher in the Ga-doped alloys than in the reference Fe65Al35 alloy. The boron addition transforms the magnetic state of the initial alloy Fe65Al35 into a ferromagnetic one exhibiting high magnetic characteristics. Substitution of V for Fe in the ternary alloys Fe65-хVxAl35 results in reduction of magnetic characteristics and collapsing of 57Fe hyperfine magnetic filed.

Mechanically Driven Dissolution of Sn in Near-Equiatomic Bcc FeCo

2012 ◽  
Vol 194 ◽  
pp. 187-193 ◽  
Author(s):  
J.M. Loureiro ◽  
Benilde F.O. Costa ◽  
Gerard Le Caër ◽  
Bernard Malaman
Keyword(s):  
Magnetic Field ◽  
Solid Solutions ◽  
Room Temperature ◽  
Hyperfine Magnetic Field ◽  
Ternary Alloys ◽  
119Sn Mössbauer Spectroscopy ◽  
X Ray Diffraction ◽  
Mechanically Alloyed ◽  
Powder Mixtures ◽  
X Ray

Ternary alloys, (Fe50−x/2Co50−x/2)Snx(x ≤ 33 at.%), are prepared by mechanical alloying from powder mixtures of the three elements. As-milled alloys are studied by X-ray diffraction and 57Fe and 119Sn Mössbauer spectroscopy. The solubility of Sn in near-equiatomic bcc FeCo is increased from ~0.5 at. % at equilibrium to ~20 at.% in the used milling conditions. The average 119Sn hyperfine magnetic field at room temperature is larger, for any x, than the corresponding fields in mechanically alloyed Fe-Sn solid solutions.

Influence of Severe Plastic Deformation on Physicomechanical Properties of Ti-40 mas % Nb Alloy

2016 ◽  
Vol 685 ◽  
pp. 525-529
Author(s):  
Zhanna G. Kovalevskaya ◽  
Margarita A. Khimich ◽  
Andrey V. Belyakov ◽  
Ivan A. Shulepov
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Cold Working ◽  
Young Modulus ◽  
Physicomechanical Properties ◽  
X Ray Diffraction ◽  
Refined Grains ◽  
X Ray ◽  
Initial Alloy ◽  
Composition Structure

The changes of the phase composition, structure and physicomechanical properties of Ti‑40 mas % Nb after severe plastic deformation are investigated in this paper. By the methods of microstructural, X-ray diffraction analysis and scanning electron microscopy it is determined that phase and structural transformations occur simultaneously in the alloy after severe plastic deformation. The martensitic structure formed after tempering disappears. The inverse α'' → β transformation occurs. The structure consisting of oriented refined grains is formed. The alloy is hardened due to the cold working. The Young modulus is equal to 79 GPa and it is less than that of initial alloy and close to the value obtained after tempering. It is possible that Young modulus is reduced by additional annealing.

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.

Phase Equilibria and Solidification of Al-Rich Ai-Ui-Cu Alloys

1990 ◽  
Vol 186 ◽  
Author(s):  
Sinn-Wen Chen ◽  
Y. Austin Chang
Keyword(s):  
Liquidus Projection ◽  
Thermodynamic Description ◽  
Type Equation ◽  
Ternary Alloys ◽  
X Ray Diffraction ◽  
Thermodynamic Models ◽  
Isothermal Sections ◽  
X Ray ◽  
Cu Alloys ◽  
Calculated Amount

AbstractA liquidus projection of the Al-rich Al-Li-Cu system is proposed. The proposed liquidus projection was based on DTA, X-ray diffraction, metallography, EPMA, SEM, and chemical analysis of 50 ternary alloys. Using these data and those reported in the literature, and thermodynamic models of Al-Li, AI-Cu and Cu-Li, a thermodynamic description of the Al-rich AI-Li-Cu system was developed. The calculated isothermal sections at several temperatures and the liquidus projection are in agreement with the experimental determinations. Combining the thermodynamic models and a Scheil-type equation, quantitative solidification paths were described. The calculated amount of primary solidification phase was compared to the experimental determination.

Superconductivity and Magnetic Ordering of Pr in CaLa1-xPrxBaCu3O7 System

1997 ◽  
Vol 11 (07) ◽  
pp. 323-331 ◽  
Author(s):  
V. P. S. Awana ◽  
Rajvir Singh ◽  
D. A. Landinez Tellez ◽  
J. M. Ferreira ◽  
J. Albino Aguiar ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Normal State ◽  
Ac Susceptibility ◽  
Magnetic Ordering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Peak Intensity ◽  
Heat Capacity Measurements ◽  
A Minor

We present the results of superconductivity, normal state magnetic susceptibility and heat capacity measurements on the tetragonal CaLa 1-x Pr x BaCu 3 O 7 compound. Ac susceptibility measurements show that the transition temperature T c of the unsubstituted sample decreases with an increase in the Pr concentration. Normal state dc magnetic susceptibility measurements performed in an applied field of 0.5 T show a Curie–Weiss behaviour in terms of the paramagnetic moment of Pr. The effective paramagnetic moment of Pr appears to be intermediate between those of the free Pr 3+ and Pr 4+ ions. For the nonsuperconducting samples i.e., x = 0.70 and 1.0, we observe an antiferromagnetic ordering temperature T N of nearly 4 K and 8 K respectively. The X-ray diffraction results show that the CaPrBaCu 3 O 7 compound is free from other phases, having a minor (less than 8%, in terms of peak intensity) impurity phase. The lower T N (8 K) of PrBaCaCu 3 O 7 as compared to the known antiferromagnetic ordering temperature of 17 K for PrBa 2 Cu 3 O 7 indicates a less deleterious effect of Pr in the present case.

Mechanochemical Synthesis of Novel Sensor Materials

2009 ◽  
Vol 1226 ◽  
Author(s):  
Monica Sorescu ◽  
Lucian Diamandescu ◽  
Adelina Tomescu
Keyword(s):  
Ball Milling ◽  
Milling Time ◽  
Gas Sensing ◽  
Mechanochemical Activation ◽  
Magnetic Characteristics ◽  
X Ray Diffraction ◽  
Recoilless Fraction ◽  
X Ray ◽  
Immiscible System ◽  
Sensing Applications

AbstractThe xZnO-(1-x)alpha-Fe2O3 and xZrO2-(1-x)alpha-Fe2O3 nanoparticles systems have been obtained by mechanochemical activation for x=0.1, 0.3 and 0.5 and for ball milling times ranging from 2 to 24 hours. Structural and magnetic characteristics of the zinc and zirconium-doped hematite systems were investigated by X-ray diffraction (XRD), Mössbauer spectroscopy and conductivity measurements. Using the dual absorber method, the recoilless fraction was derived as function of ball milling time for each value of the molar concentration involved. As ZnO is not soluble in hematite in the bulk form, the present study clearly illustrates that the solubility limits of an immiscible system can be extended beyond the limits in the solid state by mechanochemical activation. Moreover, this synthetic route allowed us to reach nanometric particle dimensions, which makes these materials very important for gas sensing applications.

CHARACTERIZATION AND MICRO-RAMAN STUDIES OF Bi2−xPbxSr2Ca2Cu3O10+δ (0 ≤ x ≤ 0.6) SUPERCONDUCTOR

1994 ◽  
Vol 08 (10) ◽  
pp. 591-603
Author(s):  
U. SINHA ◽  
S. SATHAIAH ◽  
R. N. SONI ◽  
H. D. BIST ◽  
S. C. MATHUR ◽  
...  
Keyword(s):  
Ac Susceptibility ◽  
Solubility Limit ◽  
Dc Resistivity ◽  
Apical Oxygen ◽  
X Ray Diffraction ◽  
Phonon Modes ◽  
X Ray ◽  
Percentage Volume ◽  
Pb Substitution ◽  
Scanning Electron

The X-ray diffraction (XRD), ac susceptibility, dc resistivity, and scanning electron microscopy (SEM) measurements on Bi 2−x Pb x Sr 2 Ca 2 Cu 3 O 10+δ (x = 0.0, 0.2, 0.4, and 0.6) superconductors have been correlated with the Raman scattering studies. Remarkable increases in the transition temperature and percentage volume of high T c phase are found till x = 0.4. Raman spectra also reveal dramatic changes at x = 0.4 in the phonon modes at 625 and 460 cm −1 associated with oxygen vibrations in BiO plane and apical oxygen of CuO 5 pyramid, respectively. The observed changes have been attributed to the phenomenon of oxygen redistribution among various layers. Optimum solubility limit of Pb substitution is found to be x = 0.4.

scholarly journals Corrosion properties of Zn-Ni-P alloys in neutral model medium

2014 ◽  
Vol 12 (11) ◽  
pp. 1183-1193 ◽  
Author(s):  
Vassil Bachvarov ◽  
Miglena Peshova ◽  
Stefana Vitkova ◽  
Nikolai Boshkov
Keyword(s):  
Corrosion Resistance ◽  
Xrd Analysis ◽  
Ternary Alloys ◽  
X Ray Diffraction ◽  
Model Medium ◽  
Experimental Conditions ◽  
Corrosion Properties ◽  
X Ray ◽  
Protective Ability ◽  
Corrosion Medium

AbstractThe presented work reports on the peculiarities of the anodic behavior, corrosion resistance and protective ability of electrodeposited Zn-Ni-P alloys with a different composition in a model corrosion medium of 5% NaCl. Three characteristic coating types have been investigated using experimental methods such as potentiodynamic polarization (PD) technique and polarization resistance (Rp) measurements. In addition, X-ray diffraction (XRD) analysis as well as scanning electron microscopy (SEM) coupled with an Energy-dispersive X-ray (EDAX) device were applied to determine the differences in the chemical composition and surface morphology which appeared as a result of the corrosion treatment. The data obtained are compared to those of electrodeposited pure Zn coatings with identical experimental conditions demonstrating the enhanced protective characteristics of the ternary alloys during the test period in the model medium. The influence of the chemical and phase composition of the alloys on its corrosion resistance and protective ability is also commented and discussed.

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