Study on structural, dielectric, thermal and chemical characteristics of aluminoborosilicate glasses doped by rare earth oxides.

Glasses in SiO2-Al2O3-B2O3-RO system doped with different Re2O3 (Re = La, Ce, Nd and Sm) at 4·5 mol.-% were prepared by conventional melt quenching technique. Structural, thermal durability and dielectric properties were investigated by using differential thermal analysis, Fourier transform infrared spectroscopy and precision impedance analyser respectively. Chemical durability was evaluated by weight losses of samples after immersion in HCl solution for varying times. The results showed that with increasing ionic radius of Re3+ ions (La3+<Ce3+<Nd3+<Sm3+), it was found that the fraction of non-bridging oxides and BO3 units increased. Dielectric constant and loss of doped different Re2O3 glasses decreased with the increase in frequency ranging from 40 Hz to 1 MHz, and possessed the lowest values of dielectric properties of εr = 3·83, tan δ = 7·93×10−4. In addition, the results of acid resistance showed that doping Re2O3 could improve the chemical durability in the order of La2O3>Ce2O3>Nd2O3>Sm2O3. [ABSTRACT FROM AUTHOR]