Spectroscopic studies on Fe3+ and Mn2+ doped SrB4O7 glasses

EPR and optical absorption studies on Fe3+ and Mn2+ doped strontium tetraborate (SrB4O7) glasses are carried out at room temperature. The EPR spectrum of the Fe3+ doped glass consists of signals with g-values 9.04, 4.22 and 2.04, whereas the EPR spectrum of Mn2+ doped glass exhibits a characteristic hyperfine sextet around g=2.0. The spectroscopic analyses of the obtained results confirmed distorted octahedral site symmetry for the Fe3+ and Mn2+ impurity ions. Crystal field and Racah parameters evaluated from optical absorption spectra are: Dq=790, B=700 and C=3000 cm−1 for Fe3+doped glass and Dq=880, B=700 and C=2975 cm−1 for Mn2+ doped glass.