EPR and FTIR spectroscopic studies of MO-Al2O3-Bi2O3-B2O3-MnO2 (M = Pb, Zn and Cd) glasses

Glasses of the system (30-x) MO-xAl(2)O(3)-15Bi(2)O(3)-54.5B(2)O(3)-0.5MnO(2) [M = Pb, Zn & Cd] (x = 0, 5, 10 & 15 mol%) were prepared by the normal melt quenching method. The amorphous nature of the prepared glasses was confirmed by the XRD studies. The EPR and FTIR studies were carried out at room temperature (RT). The EPR spectra exhibited three resonance signals at g approximate to 2.0 with a hyperfine structure, an absorption around g = 4.3 and a distinct shoulder at g = 3.3. Deconvoluted spectra were drawn for g approximate to 2.0 to resolve the six hyperfine lines. The electron paramagnetic resonance signal at g approximate to 2.0 indicates that the Mn2+ ions are in nearly perfectly octahedral symmetry. The low field signals at g = 3.3 and g = 4.3 are attributed to the Mn2+ ion which are in distorted rhombic symmetries. The hyperfine (HF) splitting constant (A) values suggested that the bonding between Mn2+ ions and its ligands is ionic in nature. The presence of BO3 and BO4 borate units, metal oxide cation units, Mn2+ and Bi-O bond vibrations in BiO3 units were noticed from the FTIR spectra.