Optical constants and magnetic susceptibility of xLa₂O ₃-30PbO-(70 - X) B₂O₃ glasses

Glassy system with the composition xLa₂O₃-30PbO-(70 - x)B₂O₃ with (0 ≤ x ≤ 10 mol%) has been prepared using the well known melt quenching technique. The transmittance and the reflectance spectra of the glasses have been measured and the optical constants such as: the refractive index, the optical band gap for indirect transition, the optical basicity and the average electronic polarizability have been calculated for the investigated glassy system. A correlation between the optical constants and the elastic moduli was performed. The AC magnetic susceptibility of the investigated glasses was studied above 4.3 K. The temperature dependent magnetic susceptibility deviates from the Curie law indicating that weak antiferromagnetic interactions between La ions were present in the studied system. The magnetic entropy change of the glasses was determined.