Experimental and Theoretical Investigation of the Spin Hamiltonian Parameters for the Cr3+ Ion in a BeAl2O4:Cr3+ Crystal

The electron paramagnetic resonance of the Cr 3+ ion in an alexandrite single crystal was explored. The angular dependence of the resonance fields observed using an X-band spectrometer in the crystallographic planes were analyzed using the monoclinic spin Hamiltonian. The spectroscopic splitting tensors g i and the 2 nd order zero field splitting parameters | D | and | E | for the Cr 3+ center at Al 3+ site with mirror symmetry ( C s ) in an alexandrite crystal were calculated using the crystal field theory for C s symmetry. Then, the theoretical values were compared with the experimental values. The calculated spin Hamiltonian parameters explain nicely the experimental parameters for the Cr 3+ center with mirror symmetry.