Influence of La^sub 2^O3 and Ce^sub 2^O3 additions on structure and properties of aluminoborosilicate glasses

Aluminoborosilicate glasses with different amounts of La2O3 and Ce2O3 were prepared respectively by the conventional melting-quenching method. The structure, thermal property parameters and dielectric property parameters were investigated by Fourier-Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry and the impedance analyzer. Results from FTIR displayed that the degree of polymerization increased first and then fell down with the addition of La2O3, and reached the maximum value when the amount was 0.5 mol%. Meanwhile, the degree of polymerization of glasses doped with Ce2O3 arrived at the largest as the content of Ce2O3 reached 2.0 mol%. The thermal stability of glasses doped with La2O3 got enhanced first and then deteriorated, and reached the maximum when the content was 0.5 mol%; Meanwhile, the glasses doped with Ce2O3 also fluctuated a little. The dielectric constant ([straight epsilon]) and dielectric loss (tan [alpha]) of the samples fell down as the frequency increased. The [straight epsilon] and tan [alpha] of the samples doped with La2O3 reached the minimum value when the amount got to 0.5 mol%; The [straight epsilon] of the glasses doped with Ce2O3 turned minimum when the amount was zero, but the tan [alpha] was the smallest when the amount reached 1.0 mol%.