Possible magnetic significance of faults and polytypes in R2Co17compounds

A description of the structures of R
2
Co
17
as layer structures is presented and possible stacking faults and dislocations involving the layer planes are described. The significance of the planar defects observed in R
2
Co
17
and structurally similar compounds and the effects of the various rare earth ion symmetries for the 2H, 1R, 4H, 5H and 6H(1) and 6H(2) possible modifications for R
2
Co
17
compounds on magnetic anisotropy and magnetostriction are discussed. Finally the possible influence of stacking faults on these properties is considered.