Single crystal EPR study of trivalent gadolinium in Cs2NaInCl6 in the 6 - 300 K interval

A cubic symmetry site is reported for Gd³+ in Cs2NaInCl6 at room temperature. The temperature dependence of the cubic spin-Hamiltonian parameter has been measured in the temperature interval 6-300 K using electron paramagnetic resonance (EPR) spectrometry. A thorough EPR examination for a crystal sample clearly demonstrates that there are no new symmetry sites arising in the temperature interval under study (6-300 K) suggesting, therefore, that the site symmetry remains cubic. We fit an analytical expression for the cubic spin-Hamiltonian parameter 6(0)4 as a function of temperature. The absolute sign of this spin Hamiltonian parameter is also determined.