EPR Spectra of Cr3+ Ions in Sr3Ga2Ge4O14:Cr Single Crystals

The results of investigations of chromiumdoped Sr₃Ga₂Ge₄O₁₄ single crystals by the EPRspectroscopy method are presented. It is shown that activating chromium ions form Cr³⁺ Ga³⁺ (Ge⁴⁺) substitution centers in the 1aoctahedral positions of the lattice of Sr₃Ga₂Ge₄O₁₄. Depending on the combination of occupation of the 3ftetrahedral positions of the first cationic coordination sphere by Ga³⁺ and Ge⁴⁺ ions, Cr³⁺ centers of two types are formed. Their individual magnetic spectra are characterized by axial and rhombic symmetry. The magnetic multiplicity of the axialsymmetry spectrum is equal to unity. There exist rhombicsymmetry centers of two types differing in the orientation of the principal magnetic axes and the value of the spinHamiltonian parameter E. The magnetic multiplicity of the individual magnetic spectra of rhombic centers of each type is equal to three. The detected EPR spectra of Cr³⁺ ions have been described by the spin Hamiltonian of rhombic symmetry. Its parameters and their spread have been determined.