Evaluation of the structural, optical, and γ-attenuation properties of Holmium Dolomite Glass for high-transmittance optical devices

• Published in: Optical materials 2024-03, Vol.149, p.114938, Article 114938
• Main Authors: Zakaly, Hesham M.H., Issa, Shams A.M., Saudi, Heba, Almousa, N., Shaaban, E.R., Hassan, Ahmed M.
• Format: Article
• Language: English
• Subjects: Direct and indirect energy gap; Holmium dolomite glass (HDG); Structural and optical properties; γ-attenuation properties
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2024.114938

In this study, the structural and optical properties as well as the radiation shielding capabilities of Holmium Dolomite Glass (HDG) 30CaMgC2O6–34P2O5-(36-x)CdO-(xHo2O3), (x = 0, 1, 2, 3, and 5 wt%), were investigated. The HDG samples were prepared using a melt-quenching method, and X-ray diffraction (XRD) analysis revealed that they had an amorphous structure with no prominent peaks. The FTIR spectra over a range from 4000 to 400 cm⁻1 and a deconvoluted view of the spectra within the 1600-400 cm⁻1 range were recorded. The optical properties were characterized through transmission and reflectance spectra across a wide wavelength range. HDG exhibited high optical transmission, with over 90 % average transmittance in the visible spectrum. The refractive index was found to be in the range of 2.1–2.3, while the absorption coefficient exhibited values between 0.01 and 0.1 across the studied wavelengths. The calculated direct energy gap EgOpt value for HDG is 4.43 eV which decreased to 3.91 eV upon increasing Holmium concentrations in HDG. Beyond optical properties, we delved into the radiation shielding capabilities of the HDG samples by meticulously measuring linear attenuation coefficients (μ) at multiple energy levels. The mass attenuation coefficient (μm), half value layer (T0.5), and mean free path (λ) values were then extracted from the μ measurements. Strikingly, our results showcased that the 5-H/C glass sample, showed outstanding performance, exhibiting a linear attenuation coefficient of around 0.025 cm−1 at 662 keV. This resulted in a remarkable mass attenuation coefficient of about 0.050 cm2/g, with a half-value layer of approximately 27 cm and a mean free path of 40 cm. These findings position the 5-H/C glass as an environmentally friendly and highly promising material for diverse radiation shielding applications, supported by robust numerical evidence. •HDG samples exhibit a distinct amorphous halo in XRD analysis.•FTIR spectra confirms PO4, CO3, and Mg–O bond presence in HDG.•Homogeneity across HDG samples shown by consistent FTIR patterns.•Minor band shifts in FTIR indicate subtle structural variations.•HDG series displays uniform amorphous structure with varying Ho content.