Study on the structure, thermal and optical properties in Cr2O3-incorporated MgO-Al2O3-SiO2-B2O3 glass

Study of 20MgO-20Al2O3-57SiO2 (MAS) glasses occupies a crucial position for optimizing glass performances for industrial applications. Here, we employed Cr2O3 dopant, and successfully prepared series of 20MgO-(20-x)Al2O3-57SiO2-3B2O3-xCr2O3 (MASBC) glasses with a doping level, denoted by x, ranging from 0 to 1 mol%, by conventional melt-quenching method. The investigation was systematically conducted using DSC, XRD, IR, optical absorption, electron paramagnetic resonance (EPR) and luminescence techniques. Structural analysis shows that all glass samples are amorphous in nature, and the glass network was mainly identified as the functional groups of [SiO4] and [AlO4]. From the optical absorption data, various optical parameters such as optical band gap, Urbach energy, crystal field and Racah parameters can be obtained. Besides, the luminescence and excitated spectra were recorded to confirm the presence of Cr3+ in a weak crystal field, and the luminescence lifetime was found to decrease with increased Cr2O3 due to the dipole interaction between the Cr3+ pairs (Cr3+-Cr3+). The EPR spectra of Cr2O3-doped MASBC glass exhibit two resonance signals at g = 5.33 and 1.96, indicating the characteristic of Cr3+ ions. Subsequently, according to the calculated bonding parameters, we confirm a strong ionic character of glass samples.