Structure, thermal and spectroscopic properties of Cu2 + ions doped 59B2O3–10K2O–(30-x)ZnO–xBaO (0 ≤ x ≤ 30) glass system

• Glasses in the B2O3–K2O–ZnO–BaO–CuO system were prepared using melt quenching method.
• A variety of spectroscopic (IR, EPR and optical absorption) tools were employed for characterization.
• IR studies revealed that the glass system consists of various borate groups.
• The glass transition temperature (Tg) increases with increasing BaO content.
• Bonding parameters and bonding symmetry of Cu2 + ions were calculated from optical absorption data.

X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), electron paramagnetic resonance (EPR) and optical absorption studies on 59B2O3–10K2O–(30-x)ZnO–xBaO–1CuO glasses (where x = 0, 6, 12, 18, 24 and 30 mol%) have been carried out. The amorphous nature of the glasses was confirmed using XRD and DSC measurements. The glass transition temperature (Tg) of glass samples has been estimated from DSC traces and found that the Tg increases with increasing BaO content. The IR studies have showed that the present glass system consists of [BO3] and [BO4] units in various borate groups. The spin-Hamiltonian parameters (SHP) such as g||, g⊥, and A|| have been determined from EPR spectra and it was found that the Cu2 + ion is in tetragonal distorted octahedral site with dx2‐y2  as the ground state. Bonding parameters and bonding symmetry of Cu2 + ions have been calculated by correlating EPR and optical data and were found to be composition dependent.