Magnetic properties of TlLnS2 compounds (Ln ≡ Tb, Ho and Tm)

TlLnS2 compounds (Ln ≡ Tb, Ho and Tm) crystallize in the rhombohedral structure of α-NaFeO2 type. The point symmetry of the lanthanide ions is 3 m . The parameters of the crystal field Hamiltonian were estimated from the high field magnetization (up to 14 T), assuming a trigonally distorted octahedral symmetry of the magnetic ions surrounding. The results were compared with data for other TlLnS2 compounds. The second-order crystal field parameter B2 changes similarly to the lanthanide environment deformation.