The magnetic structure of TlCrTe2

The magnetic structure of the antiferromagnetic layer compound TlCrTe2 has been determined by neutron powder diffraction. The magnetic moments on chromium are aligned along the c axis in the hexagonal cell and couple ferromagnetically within the sheets. Adjacent layers couple antiferromagnetically below the transition temperature of 145 K. This gives rise to a doubling of the c axis for describing the magnetic unit cell. The magnetic moment of the chromium atom is 3.39(4) μB at 10 K in line with localised 3d3 of Cr3+. Electronic structure calculations on TlCrTe2 of density-functional type (GGA) show a clear driving force for the ferromagnetic coupling in the layers and a lowering of the total energy upon magnetic ordering, the theoretical magnetic moment being in almost quantitative agreement with the experiment.