Speaker
Ms
Nora Hänni
(Universität Bern)
Description
The magnetic order in RbCoCl3 was investigated in a series of neutron scattering experiments at SINQ, PSI, on powder and single-crystal samples between 1.5 K and 300 K. RbCoCl3 is a hexagonal perovskite of CsNiCl3 type structure. It crystallizes in space group P63/mmc with lattice parameters of a=7.0003(3) Å and c=5.9959(2) Å at room temperature. Upon cooling the octahedrally coordinated high-spin Co2+ ions show one-dimensional (1D) antiferromagnetic (AFM) interactions along the c-axis. At TN1=28 K 3D AFM order occurs with k=(1/3,1/3,1). The magnetic moments are aligned along the c-axis with μz=3.97(2) μB and an amplitude modulation in the ab-plane. A second magnetic phase transition is observed at TN2=13 K where the moments along the c-axis increase to μz=4.08(1) μB and two additional propagations k=(0,0,1) and k=(1/2,0,1) occur. The k-vectors were confirmed by single crystal neutron scattering. In agreement to the neutron scattering data, the magnetic susceptibility along the c-axis shows a broad maximum at 90 K due to 1D AFM interactions along the [CoCl6/2]- chains. The heat capacity shows a λ-anomaly at TN1 but no effect at TN2. Results from inelastic neutron scattering on RbCoCl3 will be presented separately.
Primary author
Ms
Nora Hänni
(Universität Bern)
Co-authors
Christian Rueegg
(Paul Scherrer Institut)
Denis Cheptiakov
(Paul Scherrer Institut)
Dr
Marisa medarde
(Paul Scherrer Institut)
