Electron paramagnetic resonance studies of Mn2+ ions in beta-Ga2O3 single crystal

A Mn2+ ion-doped beta -Ga2O3 single crystal was grown by using a floating z one method. By employing an X-band electron paramagnetic resonance (EPR) sp ectrometer, Mn2+ EPR spectra were recorded at room temperature. The rotatio n patterns in the crystallographic planes together with spin-Hamiltonian pa rameters of Mn2+ show unequivocally that the actual local site symmetry of the Mn2+ ion is monoclinic. A Mn2+ ion lies on a site with a two-fold rotat ion symmetry, parallel to the monoclinic axis of the crystal. The spectrosc opic splitting tensor g, zero-field splitting parameters B(k)(q)s, and the hyperfine tensor A are determined with the effective spin Hamiltonian. It t urns out that the Mn2+ ion lies at only one site, the substitutional site f or the Ga3+ ion in the oxygen octahedron rather than in tetrahedron. Energy levels of the ground state for a Mn2+ ion embedded in the beta -Ga2O3 crys tal are calculated. (C) 2001 American Institute of Physics.