Raman studies and optical properties of some (PbO)x(Bi2O3)0.2(B2O3)0.8−x glasses

Abstract

AbstractFive (PbO)x(Bi2O3)0.2(B2O3)0.8−x glasses, where x = 0, 0.2, 0.3, 0.4 and 0.6, were prepared. The dilatometric glass transition temperature (Tg) was found in the region 470 (x = 0)≥ Tg ( °C) ≥ 347 (x = 0.6), and the density (ρ) varied within 4.57 (x = 0) ≤ ρ (g/cm3) ≤ 8.31 (x = 0.6). Raman spectra indicated the conversion of BO3 to BO4 entities for low x values but for x > 0.3, namely, for x → 0.6, back‐conversion occurred, most probably. From the measurements of the optical transmission on very thin bulk samples, the room temperature optical gap values (Eg) were determined to be in the range 4.03 (x = 0)≥ Eg (eV) ≥ 3.08 (x = 0.6). The temperature (T) dependence of the optical gap (Eg(T)) in the region 300 ≤ T(K) ≤ 600 was examined and approximated by a linear relationship of the form of Eg(T) = Eg(0)− γT, where γ × 10−4(eV/K) varied from 5.1 to 6.8. The non‐linear refractive index (n2) was estimated from the optical gap values and it was found to correspond to the n2 values calculated from the experimental third‐order non‐linear optical susceptibility taken from the literature. Copyright © 2008 John Wiley & Sons, Ltd.