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.

Synthesis and Magnetic Properties of La-Doped Ni Ferrites

2010 ◽  
Vol 148-149 ◽  
pp. 736-739
Author(s):  
Ju Hua Luo
Keyword(s):  
Single Phase ◽  
Raw Materials ◽  
Nominal Composition ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetic Parameters ◽  
Ft Ir ◽  
Mechanochemical Treatments ◽  
La Doped

Ni ferrites doped with lanthanum with a nominal composition of NiFe2-xLaxO4(x=0.05) were obtained by mechanochemical treatments using NiCO3•2Ni (OH)2•4H2O , La2O3 and Fe2O3 as raw materials. Both series of materials were characterised by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM). The results indicated that the mixture became amorphous stage after ball-milled for 30 h, and single phase NiFe1.95La0.05O4 could be obtained after calcined at 700 for 2 h. The addition of lanthanum resulted in a reduction of all the magnetic parameters evaluated.

Two series of rare earth metal-rich ternary aluminium transition metallides – RE6Co2Al (RE=Sc, Y, Nd, Sm, Gd–Tm, Lu) and RE6Ni2.25Al0.75 (RE=Y, Gd–Tm, Lu)

2018 ◽  
Vol 73 (11) ◽  
pp. 927-942 ◽  
Author(s):  
Frank Stegemann ◽  
Oliver Janka
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Rare Earth Metal ◽  
Magnetic Measurements ◽  
Earth Metal ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Antiferromagnetic Ordering ◽  
Arc Melting

AbstractThe rare earth metal-rich cobalt and nickel aluminium compounds with the general compositions RE6Co2Al (RE=Sc, Y, Nd, Sm, Gd–Tm, Lu) and RE6Ni2.25Al0.75 (RE=Y, Gd–Tm, Lu) have been synthesised from the elements by arc-melting, followed by annealing. Single-crystal X-ray diffraction experiments on Y6Co2.02(1)Al0.98(1) (Ho6Co2Ga type; Immm; a=944.1(2), b=952.4(2), c=999.0(2) pm; wR2=0.0452, 1123 F2 values, 35 variables) and Y6Ni2.26(1)Al0.74(1) (Ho6Co2Ga type; Immm; a=938.30(5), b=959.45(5), c=996.05(6) pm; wR2=0.0499, 1131 F2 values, 35 variables) revealed that the compounds form solid solutions according to the general formula RE6(Co/Ni)2+xAl1−x with different homogeneity ranges. The compounds of the Ni series can be obtained in X-ray pure form only with the nominal composition RE6Ni2.25Al0.75. A significant increase of the U22 component of the anisotropic displacement parameters of the Co/Ni2 atoms (4g site) was observed that requires a description of the structure with a split-position model at RT. Further investigations by low temperature (90 K) single-crystal X-ray diffraction experiments of Y6Co2.02(1)Al0.98(1) showed a significant decrease of U22. Magnetic measurements were conducted on the X-ray pure members of the RE6Co2Al (RE=Y, Dy–Tm, Lu) series. Antiferromagnetic ordering was observed for the members with unpaired f electrons with Néel temperatures up to TN=48.0(1) K and two spin reorientations for Dy6Co2Al.

Magnetic and Microstructural Aspects of the Bulk Metallic Glassy Materials Nd60Fe30Al10

2001 ◽  
Vol 674 ◽  
Author(s):  
N. H. Dan ◽  
N. X. Phuc ◽  
V. H. Ky ◽  
N. M. Hong ◽  
N. Chau ◽  
...  
Keyword(s):  
Room Temperature ◽  
Amorphous Material ◽  
Magnetic Hysteresis ◽  
Degree Of Crystallinity ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Cast Sample ◽  
X Ray ◽  
Glassy Materials ◽  
Ferromagnetic Bulk

ABSTRACTThe ferromagnetic bulk metallic glass (BMG) Nd60Fe30Al10system exhibits extremely large coercivities at low temperature and moderate coercivities near room temperature. The magnetic hardness, as best evidenced by the onset of magnetic irreversibility, was studied in bulk suction-cast and melt-spun alloys with the nominal composition Nd60Fe30Al10. Systematic x-ray diffraction studies of the degree of crystallinity performed as a function of position within the bulk suction-cast samples is found to correlate with the variation in the room-temperature magnetic hysteresis character. X-ray diffraction data clearly shows the presence of both crystallites and amorphous material on the samples' outmost surfaces; the amorphous phase content increases with distance into the cast sample. These results underscore the importance of solidification conditions and attendant nanophase selection, on the resultant magnetic properties of this class of alloys.

Magnetic properties of (Sr1.85Ln0.15)FeMoO6 with Ln = Sr, La, Ce, Pr, Nd, Sm and Eu

2011 ◽  
Vol 239-242 ◽  
pp. 3109-3112 ◽  
Author(s):  
Qin Zhang ◽  
Qing Wang ◽  
Zhen Cui Sun ◽  
Ke Yan Wang
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Ionic Radius ◽  
Single Phase ◽  
Magnetic Measurements ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rare Earth Doped ◽  
The Eu

Rare-earth-doped compounds (Sr1.85Ln0.15)FeMoO6(Ln=Sr, La, Ce, Pr, Nd, Sm and Eu) have been prepared by solid-state reaction. Crystal structure and magnetic properties were investigated by means of X-ray diffraction and magnetic measurements. All the samples are single phase and belong to the I4/m space group. Due to the competing contributions of electron doping and steric effects, the unit-cell volume of the doped compounds changes slightly and does not vary systematically with the ionic radius of the rare-earth ions. The temperature dependence of the magnetization of (Sr1.85Ln0.15)FeMoO6indicates that the Curie temperature of the doped compounds has increased upon doping, except for the Eu-doped compound.

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.

Magnetic and Magnetostrictive Properties of Tb-Dy-Ho-Fe-Co Alloys

2009 ◽  
Vol 152-153 ◽  
pp. 7-10 ◽  
Author(s):  
Irina S. Tereshina ◽  
S.A. Nikitin ◽  
G.A. Politova ◽  
A.S. Ilyushin ◽  
A.A. Opolenko ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Rare Earth ◽  
Applied Magnetic Field ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Standard Strain ◽  
X Ray ◽  
Structural And Magnetic Properties ◽  
Co Alloys

In this work, the structural and magnetic properties of single-phase TbxDyyHoz(Fe,Co)2 (x + y + z = 1) alloys have been investigated by means of X-ray diffraction, 57Fe Mossbauer spectroscopy, magnetization measurements and a standard strain gage technique. The magnetostriction of TbxDyyHoz(Fe,Co)2 was examined against an applied magnetic field up to 10 kOe in 80 - 400 K temperature range. The Co-containing compounds are found to have high values of magnetostrictive susceptibility due to compensation of magnetic anisotropy in both the rare-earth and 3d transition metals sublattices.

scholarly journals Thermal Analysis of High Entropy Rare Earth Oxides

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3141 ◽  
Author(s):  
Sergey V. Ushakov ◽  
Shmuel Hayun ◽  
Weiping Gong ◽  
Alexandra Navrotsky
Keyword(s):  
Thermal Analysis ◽  
Rare Earth ◽  
Single Phase ◽  
Liquidus Surface ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
X Ray ◽  
High Entropy ◽  
Rare Earth Sesquioxides

Phase transformations in multicomponent rare earth sesquioxides were studied by splat quenching from the melt, high temperature differential thermal analysis and synchrotron X-ray diffraction on laser-heated samples. Three compositions were prepared by the solution combustion method: (La,Sm,Dy,Er,RE)2O3, where all oxides are in equimolar ratios and RE is Nd or Gd or Y. After annealing at 800 °C, all powders contained mainly a phase of C-type bixbyite structure. After laser melting, all samples were quenched in a single-phase monoclinic B-type structure. Thermal analysis indicated three reversible phase transitions in the range 1900–2400 °C, assigned as transformations into A, H, and X rare earth sesquioxides structure types. Unit cell volumes and volume changes on C-B, B-A, and H-X transformations were measured by X-ray diffraction and consistent with the trend in pure rare earth sesquioxides. The formation of single-phase solid solutions was predicted by Calphad calculations. The melting point was determined for the (La,Sm,Dy,Er,Nd)2O3 sample as 2456 ± 12 °C, which is higher than for any of constituent oxides. An increase in melting temperature is probably related to nonideal mixing in the solid and/or the melt and prompts future investigation of the liquidus surface in Sm2O3-Dy2O3, Sm2O3-Er2O3, and Dy2O3-Er2O3 systems.

Structure and Ionic Conductivity of Ln2Zr2O7-Type Rare Earth Zirconates

2007 ◽  
Vol 336-338 ◽  
pp. 420-423 ◽  
Author(s):  
Rui Zhang ◽  
Qiang Xu ◽  
Wei Pan ◽  
Chun Lei Wan ◽  
Long Hao Qi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Solid State ◽  
Ionic Conductivity ◽  
Single Phase ◽  
Complex Impedance ◽  
Pyrochlore Structure ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
X Ray

Three rare earth zirconates (Sm2Zr2O7, Gd2Zr2O7 and Er2Zr2O7) were prepared by solid state reaction. The crystal structure and ionic conductivity of these zirconates were characterized by X-ray diffraction (XRD) and complex impedance spectroscopy. The results show that Sm2Zr2O7 exhibits single-phase pyrochlore structure and Er2Zr2O7 exhibits single-phase fluorite structure, while Gd2Zr2O7 has pyrochlore and fluorite structure. Among three zirconates, the ionic conductivity of Sm2Zr2O7 is highest, while that of Er2Zr2O7 is lowest.

SUPERCONDUCTIVITY IN THE U-Y-Ba-Cu-O SYSTEM

1987 ◽  
Vol 01 (07n08) ◽  
pp. 323-326 ◽  
Author(s):  
Q.Z. QIN ◽  
A.D. HE ◽  
W.J. JIA ◽  
L.D. MA ◽  
Z.Y. HUA
Keyword(s):  
Single Phase ◽  
Ambient Pressure ◽  
Raw Material ◽  
Material Structure ◽  
Nominal Composition ◽  
Uranium Oxides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zero Resistance ◽  
Superconducting Oxides

High Tc superconductivity has been observed in a new U-Y-Ba-Cu-O system at ambient pressure. The zero-resistance temperature in the sample with nominal composition of U0.1Y1.1Ba0.8CuO4−δ is 87K with a width of 2K. X-ray diffraction analysis shows that none of the peaks could be fitted to the uranium oxides and the other raw material structure, and its pattern might be attributed to new multiple phases with structure different from the known single-phase superconducting oxides.

VARIATION OF Tc IN SINGLE PHASE Bi4Sr3Ca3Cu4O16−x SYSTEM

1990 ◽  
Vol 04 (22) ◽  
pp. 1385-1391 ◽  
Author(s):  
M. NASIR KHAN ◽  
FARID A. KHWAJA
Keyword(s):  
High Temperature ◽  
Critical Temperature ◽  
Solid State ◽  
Single Phase ◽  
High Temperature Superconductor ◽  
Interlayer Spacing ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
X Ray

The variation of critical temperature Tc in a single-phased ceramic high temperature superconductor Bi 4 Sr 3 Ca 3 Cu 4 O y is studied using techniques like X-ray diffraction, magnetic and electrical measurements. Samples of Bi-Sr-Ca-CuO having nominal composition 4334 are synthesized by solid state reaction using appropriate amounts of Bi 2O3, SrCO 3, CaCO 3 and CuO powders. It has been shown that the Tc in this material can be raised from 98 K in the fast quenched sample to 120 K in the furnace-cooled one. The higher values of Tc in furnace cooled specimens as compared with the Tc in quenched samples have been attributed to the variation in the interlayer spacing in these compounds. It is concluded that electron density and hence the attractive interaction between pairs are increased due to shortening of the interlayer spacing in the furnace-cooled sample, leading to an increase of its Tc.

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