Investigations on magnetic properties of La3Ga5.5Ta0.5O14 single crystals doped with Er3+ ions

La3Ga5.5Ta0.5O14 (LGT) single crystals doped with 3.8 at. % of Er3+ ions have been investigated by performing Electron Paramagnetic Resonance (EPR) and magnetic susceptibility measurements. The results of EPR measurements show a large anisotropy of spin Hamiltonian parameters belonging to isolated erbium centers. In addition to the isolated erbium centers a small number of pairs of erbium ions was also observed. Based on the obtained spin Hamiltonian parameters we have determined the symmetry of isolated and paired erbium ions as being at least C4. From magnetization measurements it does not result strong coupling between Er3+ ions and the lattice of LGT crystals.