MAGNETIC INTERACTIONS IN Sm(Fe/Mn)6Sn6 INTERMETALLICS

Abstract

The magnetic structure of the transition metal sublattice in induction-melted SmMn 6-x Fe x Sn 6 intermetallic alloys ( x = 0, 0.5, 1.0, 1.5, and 2.0) K have been studied by x-ray and neutron diffraction techniques and SQUID measurements. These intermetallics crystallize in the HoFe 6 Sn 6-type structure with the space group I mmm while the SmMn 6-x Fe x Sn 6 intermetallic alloys ( x = 0.5, 1.0, 1.5, and 2.0) have the TbFe 6 Sn 6-type structure with the space group C mcm. Lattice constant, a, b, c, and unit cell volume contract with increasing iron content The net magnetization exhibits a small magnitude variation within the iron content range investigated. The magnetic moment of the iron sublattice couples positively with ferromagnetically coupled manganese and samarium moments. The Curie temperature (Tc) first increases, goes through a maximum at about x = 1.5, and then decrease again with the increasing iron content. The easy direction of magnetization for all of the samples is parallel to the bc plane of the unit cell at 300 K.