Electron paramagnetic resonance study of Ce3+, Dy3+ and Yb3+ in Cs2NaYCl6. A crystal with sites of perfect octahedral symmetry

Abstract

The X-band e.p.r. spectra at 4.2 K of cerium(III), dysprosium(III), and ytterbium(III) doped into cubic Cs₂NaYCl₆ are reported. The magnitude of the g-factor and the isotropic nature of both g and the line width indicate that the ions occupy sites of exact octahedral symmetry. Analysis of the spin Hamiltonian parameters of these and other possibly octahedral, lanthanide ions implies that the admixture of ligand orbitals into the ground state is the order chloride > oxide > fluoride. However, the order of mixing of free ion terms into the ground state is oxide > chloride.