Magnetic properties of (Sm0.5 Tb0.5) 2 Fe17-x Gax [mentioned subsequently as SmTbFe17-x Gax] have been investigated. All the compounds have formed in rhombohedral Th2 Zn17 structure with traces of α-Fe. The saturation magnetization decreases with increasing x and is attributed to the modification of the density of states of 3d band due to the low lying 3p band of Ga. The increase of Curie temperature up to x=3 and subsequent decrease is explained on the basis of band narrowing. The easy direction of magnetization is in the ab plane up to x=5 and changes along the c axis for x=7. © 2005 American Institute of Physics.

G. Markandeyulu

Department Of Physics

J. C. Ingersoll

V. S. Murty

K. V.S. Rama Rao

POWER X-RAY DIFFRACTOGRAMS

Rietveld refinement

Spin reorientation

Thermomagnetic analysis

Argon

Crystal Structure

dysprosium

Erbium compounds

Permanent magnets

X ray powder diffraction

Magnetic properties

Fulltext

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IIT Madras

Magnetic properties of SmTbFe17−xGax [0⩽x⩽8]

Journal of Applied Physics

The structural and magnetic properties of Gd3(Fei1-xAlx)27.5Ti1.5 (0.1-0.4) have been investigated by X-ray diffraction (XRD), magnetization and Curie temperature (Tc) measurements. All the compounds have formed in Nd3 (Fe,Ti)29 (3:29) type structure with Gd(Fe,Ti)12 (1:12) phase as the secondary phase and traces of α-Fe. The unit cell parameters increase anisotropically with the A1 content. The saturation magnetization decreases with increasing A1 and is attributed to the magntovolume effect and the modification of the density of states (DOS). The increase of Curie temperature up to x = 0.3 and subsequent decrease is explained on the basis of band narrowing. The easy direction of magnetization (EMD) is away from the ab-plane up to x = 0.3 changes to along ab-plane for x = 0.4. © 2006 IEEE

IEEE Transactions on Magnetics

Structural and Magnetic Properties of Gd3(Fe1-xAlx)27.5Ti1.5

The structural and magnetic properties of SmTb Fe17-x Alx (x=0-8) and SmTb Fe17-x Six (x=0-3.5) were investigated by x-ray-diffraction and magnetization studies. All the compounds stabilize in rhombohedral structure. The lattice parameters are found to increase with Al substitution whereas they are found to decrease with Si substitution. The rates of the decrease of saturation magnetization (Ms) value with the substitution of Al and Si are almost the same. The easy direction of magnetization (EMD) is in the ab plane up to an Al concentration of x=7 and has a tendency to shift towards the c axis at x=8. All the compounds with Si are seen to have the EMD in the ab plane. Electron-magnon scattering is seen to contribute to the electrical resistivity in both Al- and Si-substituted compounds; in the temperature range of 30-60 K and at higher temperatures, scattering due to phonons is observed. © 2005 American Institute of Physics.

Effect of Al and Si substitutions on the magnetic properties of SmTbFe 17

R2Fe17 (R = rare earth) intermetallic compounds constitute one of the most important classes of materials identified as high-energy permanent magnet materials. They crystallize either in the rhombohedral Th2Zn17 structure (for light R) or in the hexagonal Th2Ni17 structure (for heavy R). In this article, we discuss the variations in the lattice parameters (unit cell volume), site occupancies and Curie temperature when non-transition and transition metals are substituted for Fe in R2Fe17 compounds.

Physica Status Solidi (A) Applied Research

On the structural and magnetic properties of R2Fe17-x(A,T)x (R = rare earth; A = Al, Si, Ga; T = transition metal) compounds

A detailed investigation of the structure and magnetic properties of R2Fe17-xGax (R = Tm, Er and Sm and x = 0-7) was carried out by means of powder X-ray diffraction, magnetization and AC magnetic susceptibility measurements. With increasing Ga content, a structural transformation from hexagonal Th2Ni17-type structure to rhombohedral Th2Zn17-type structure is observed in compounds Er2Fe17-xGax (x = 0-7) and Tm2Fe17-xGax (x = 0-7). The compounds Sm2Fe17-xGax (x = 0-7) crystallize in rhombohedral Th2Zn17-type structure. The Curie temperature increases in the initial Ga concentration range, reaches a maximum and then decreases at higher Ga concentration. The exchange interaction parameter JFeFe reaches a maximum and then decreases whereas the value of JRFe is almost independent of Ga concentration. X-ray diffraction measurements on magnetically aligned powder samples show a uniaxial anisotropy for compounds with at x = 2, 3 and 4 in the Sm2Fe17-xGax series whereas, it was observed for x = 7 in the Tm2Fe17-xGax compounds.

Physica B: Condensed Matter

Structural, magnetic and exchange interaction studies on R2Fe17-xGax (R = Tm, Er and Sm) compounds

An x-ray diffraction study of (Pr0.5Er0.5)2Fe17-xAlx (0≤x≤10) shows an expansion of its unit cell with x. The crystal structure changes from hexagonal Th2Ni17 to rhombohedral Th2Zn17 at x = 6. The magnetic moment decreases by increasing the Al concentration. This effect may be due to the charge transfer from Al to the 3d band of Fe. The Curie temperatures are found to increase with Al up to x = 3 and then decrease up to x = 10, and the possible underpinning mechanisms are discussed. X-ray diffractograms of the magnetically aligned samples indicate that the easy magnetization directions of the samples with x = 1,2,3, and 4 lie on a cone about the c axis. Electrical resistivity measurements show that the residual resistivity increases drastically with the Al concentration. The temperature coefficient of resistivity becomes almost zero for intermediate Al concentrations. © 1995 American Institute of Physics.

Structural, magnetic, and electrical properties of (Pr0.5Er0.5)2Fe17-xAlx

Physical Review Letters

Ab InitioCalculations of the Curie Temperature of Complex Permanent-Magnet Materials

Physical Review B

Site occupancies of Si atoms and Curie temperatures forSm2Fe17−xSix

Magnetic properties of SmTbFe 17-xGa x [0≤x≤8]

Journal	Journal of Applied Physics
ISSN	00218979
Open Access	No