R 2 Fe 17 (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 Th 2 Zn 17 structure (for light R) or in the hexagonal Th 2 Ni 17 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 R 2 Fe 17 compounds.

On the Structural and Magnetic Properties of R2Fe17—x(A,T)x (R = Rare Earth; A = Al, Si, Ga; T = Transition Metal) Compounds

Theoretical study on the structure for R2Co17 (R = Y, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er) and R2Co17T (T = Be, C)

Structural and magnetic properties of HoErFe17−xGax compounds

Structural and magnetic properties of ErPrFe17−xMx (M=Ga, Si; x=0–3.5)

Crystallographic and magnetic studies on iron-rich mixed rare-earth intermetallics (Nd/Tb)2(Fe/Al)17

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.

K. V. S. Rama Rao

Papers

Structural, magnetic, and electrical properties of (pr0.5er0.5)2fe17-xalx