Structural characteristics of rare earth (R=Tb, Ho, Er) ternary magnetic intermetallics RFe sub x Al sub 12-x with iron concentrations x=6

Neutron powder diffraction has been performed on ternary intermetallic TbFe sub 6 Al sub 6 , HoFe sub 6 Al sub 6 , and ErFe sub 6 Al sub 6 at 4.2K, 300K and 500K. These isotypic compounds crystallize in the ThMn sub 12 -type structure with strong preference site occupation of Fe and Al for the 8f and 8i sites, respectively, the 8j site being populated by both Fe and Al. Temperature dependent unit cell parameters and interatomic distances are given. Structural characteristics and details are also discussed in view of the ferrimagnetic ordering around 340K.