Low Temperature Absorption Spectrum of Mn²⁺ Ions Doped in Diglycine Barium Chloride Monohydrate

Abstract

The absorption spectrum of Mn²⁺ ions doped in diglycine barium chloride monohydrate (DGBC) has been studied at liquid nitrogen temperature (77 K) in the region λ 6000 Å to 3000 Å. Three of the observed bands showed well resolved fine structure. The splitting of ⁴E_g (G) band is explained as due to exciton-magnon interaction. Weak bands on either side of ⁴A_1g (G) band are assigned to phonon progressions withν = 200 cm The fine structure of the ⁴T_2g (D) band is analysed in terms of spin-orbit splitting associated with the vibrational frequency of the hydrogen bond (185 cm⁻¹). The observed band positions are fitted with four parameters B,C, D_q and α, and the best fit is obtained with B = 810 cm⁻¹, C = 2980 cm⁻¹, D_q = 760 cm⁻¹ and α = 76 cm⁻¹. justify our assumption of octahedral site symmetry for the metal ion in the crystal. From the observed absorption spectrum it is possible to determine the crystal phonons in Mn²⁺ doped DGBC and it is found to be about 200 cm⁻¹.