Mixed alkali effect and samarium ions effectiveness on the structural, optical and non-linear optical properties of borate glass

Borate glasses containing lithium, sodium, and samarium ions were prepared by conventional melt annealing technique. The structural units show the presence of BO3, and BO4 units while samarium ions favored to link with OH group. Density and molar volume show the impact of the replacement sodium ions by lithium. The density values increase with increasing lithium content up to 20 mol% and decrease for free sodium borate glass (30 Li2O or 0 Na2O). Optical and photoluminescence investigations were carried to determine the optical parameters such as optical band gap, refractive index, etc. The optical band gap and refractive index values show the nonlinearity trend due to the change occurred at 10% Li2O content. The non-linear optical parameters were determined and studied in terms of the refractive index and the impact of the mixed alkali effect.