ESR spectroscopy on the coupled spin tetrahedral system Cu₂Te₂O₅Cl₂

Systems with reduced dimensionality and magnetic frustration gained considerable attention in modern solid state research as both phenomena individually lead to an enhancement of the impact of fluctuations on magnetic properties and low-energy excitations. The coupled spin tetrahedral compound Cu₂Te₂O₅Cl₂ belongs to a class of materials which allow to study the interplay of both effects. In our work we performed a high-field high-frequency ESR study in order to investigate the magnetic anisotropies present in this system as well as the spin dynamics of the compound. Measurements were conducted over a wide frequency and temperature range revealing a small g-factor anisotropy at room temperature which is consistent with torque magnetometry results. Furthermore, the temperature dependence of the linewidth indicates the onset of slowing down of spin fluctuations far above the ordering temperature.