Papers by Author: K.H.J. Buschow

Abstract: Neutron powder diffraction on the binary intermetallics Er₅Mg₂₄ and Tm₅Mg₂₄ confirms their isostructural and pure crystallization in the Ti₅Re₂₄-type structure (space group I 4 3m, Z = 2)with rare earths located in 2a(0,0,0) and 8c(x,x,x) and Mg in two different 24g(x,y,x) sites. Room temperature lattice constants are 11.263(2) Å and 11.215(1) Å for the Er and Tm compound, respectively. Atomic positions have been refined. Both compounds order ferromagnetically below Curie temperatures of 17.5(5) K and 7.5(5) K for Er₅Mg₂₄ and Tm₅Mg₂₄, respectively. The magnitudes of the Er moments at 4.2 K are 7.5(2) µ_B and 4.4(2)µ_B on the 2a and the 8c sites, respectively. The Tm moments which have been refined from 2 K measurements amount to 3.0(3)µ_B and 2.8(2) µ_B, respectively. The temperature dependencies of the magnetic Bragg intensities reveal distinct deviations from Brillouin curves for J = 15/2 (Er) and J = 6 (Tm) systems and indicate a complex magnetic exchange.