Existence and properties of Co-rich 3:29-type of compounds synthesized with heavy rare earths

Abstract In this work, the synthesis and the study of rare earth–transition metal intermetallic compounds with nominal stoichiometry R 3 (Fe 1− x Co x ) 29− y Cr y (R=Tb, Ho and ( x , y )=(0.6, 4.5) and (0.8, 5.5)) is presented. The compounds were synthesized with the typical arc-melting technique from high-purity constituents and subsequently annealed at various temperatures. Both series were found to produce practically single-phase samples after the annealing procedure with a significant difference in crystal structure. For R=Tb, the monoclinic 3:29 phase (Nd 3 (Fe, Ti) 29 -type, space group A2/m) is produced, while for R=Ho, a disordered variant of the hexagonal 2:17 phase (Th 2 Ni 17 -type, space group P6 3 /mmc) occurs. The magnetic interactions for the samples with x =0.8 are generally weaker than those with less Co, especially in the case of R=Ho. The magnetocrystalline anisotropy of all the compounds has a planar character.