title: The magnetic structure of EuCu₂Sb₂.
abstract: Antiferromagnetic ordering of EuCu2Sb2 which forms in the tetragonal CaBe2Ge2-type structure (space group P4/nmm #129) has been studied using neutron powder diffraction and (151)Eu Mössbauer spectroscopy. The room temperature (151)Eu isomer shift of -12.8(1) mm s(-1) shows the Eu to be divalent, while the (151)Eu hyperfine magnetic field (B(hf)) reaches 28.7(2) T at 2.1 K, indicating a full Eu(2+) magnetic moment. B(hf)(T) follows a smooth S = 7/2 Brillouin function and yields an ordering temperature of 5.1(1) K. Refinement of the neutron diffraction data reveals a collinear A-type antiferromagnetic arrangement with the Eu moments perpendicular to the tetragonal c-axis. The refined Eu magnetic moment at 0.4 K is 7.08(15) μ(B) which is the full free-ion moment expected for the Eu(2+) ion with S = 7/2 and a spectroscopic splitting factor of g = 2.
authors.affiliation: Centre for the Physics of Materials and Physics Department, McGill University, Montréal, QC, H3A 2T8, Canada.
authors.forename: D H
authors.initials: DH
authors.lastname: Ryan
authors.forename: J M
authors.initials: JM
authors.lastname: Cadogan
authors.forename: V K
authors.initials: VK
authors.lastname: Anand
authors.forename: D C
authors.initials: DC
authors.lastname: Johnston
authors.forename: R
authors.initials: R
authors.lastname: Flacau