Enhanced optical and structural traits of irradiated lead borate glasses via Ce3+ and Dy3+ ions with studying Radiation shielding performance

Abstract

Lead borate glass is the best radiation shielding glass when lead is in high concentration. However, it has low transparency after radiation exposure. Radiation decreases transparency due to chemical and physical changes in the glass matrix, such as creating or healing defects in the glass network. The addition of rare earth elements like cerium and dysprosium oxides to lead borate glasses can improve their transparency and durability as radiation shielding barriers. The newly manufactured glasses' optical absorption, structural, and radiation shielding properties were measured. The optical characteristics of the generated samples were examined to determine the effect of the cerium/dysprosium ratio on the structural alterations, specifically in the presence of bridging oxygen (BO) and non-bridging oxygen (NBO). Incorporating Ce³⁺ results in peaks at 195 nm for borate units, 225 nm for Ce³⁺, and a broadened peak at 393 nm due to overlapping peaks for Ce³⁺ and Ce⁴⁺ in the UV region. By adding Dy, multiple peaks are observed at 825, 902, 1095, 1275, and 1684 nm, corresponding to the transition from ⁶H_15/2 ground state to ⁶F_5/2, ⁶F_7/2, ⁶F_9/2, ⁶F_11/2, and ⁶H_11/2. The samples were also tested before and after exposure to gamma irradiation from a ⁶⁰Co source at a dose of 75 kGy to assess their stability against radiation. The energy gap value during irradiation shows decreased non-bridging oxygen. The energy gap difference before and after irradiation for the M4 sample shows higher NBO to BO conversion, reducing radiation damage and improving structural stability. Furthermore, X-ray photoelectron spectroscopy was utilized to get insight into the coordination chemistry of the created glass samples. The half-value layer (HVL), radiation protection efficiency (RPE), neutron removal cross-section (FRNCS), mean free path (MFP), mass attenuation coefficients (MAC), and effective atomic numbers (Z_ef) of the glassy structure were calculated theoretically to assess its radiation shielding qualities. The linear attenuation coefficient order for the prepared samples was M1 > M2 > M3 > M4. The FRNCS values were 0.090, 0.083, 0.081, and 0.079 cm^-1 for samples M1, M2, M3, and M4, respectively.

Keywords: Cerium; Dysprosium; Lead borate glass; Optical properties; Radiation shielding; XPS.

Fig. 1

The dynamic view of the radiation attenuation simulation system used for the prepared M-X glass samples.

Fig. 2

XPS spectra of prepared glass samples.

Fig. 3

Normalized absorbance spectra of lead borate glasses (undoped, doped with Dy or Ce, and coped with Dy-Ce).

Fig. 4

Normalized absorbance spectra of lead borate glasses before and after irradiation with 75 kGy (a) M1 (b) M2 (c) M3 and (d) M4.

Fig. 5

Tauc plots for all samples (a) before and (b) after irradiation by 75 kGy.

Fig. 6

Urbach energy values for all samples (a) before and (b) after irradiated with 75 kGy.

Fig. 7

Influence of gamma-ray energy on linear attenuation coefficient of (a) photo electric, (b) compton scattering, and (c) pair production for the M-X glass samples.

Fig. 8

The mass attenuation coefficients (µ_m) vs. the photon energy for the prepared M-X glass samples.

Fig. 9

The linear attenuation coefficient for the M-X glass samples with reference concretes and glasses.

Fig. 10

(a) The half value layer (HVL), (b) The tenth value layer (TVL), and (c) The mean free path (MFP) for the prepared glass M-X samples vs. the photon energy.

Fig. 11

(a) The transfer factor (TF) and (b) the radiation protection efficiency (RPE) for the prepared M-X glass samples vs. photon energy.

Fig. 12

The effective atomic number (Zef) for the prepared M-X glass samples vs. photon energy.

Fig. 13

Comparison of the fast neutron removal cross-section (FRNCS) for the prepared M-X glass samples and commercial glass and concrete samples.

Fig. 14

The fast neutron removal cross-section (FRNCS), the half value layer (HVL_FRNCS), and the relaxation length (λ_FRNCS) for the prepared M-X glass samples.