[21a-P8-1~27] 16 Amorphous and Microcrystalline Materials（Poster）

[21a-P8-1] Rare-earth dependence of ultraviolet absorption edge of rare-earth and phosphorus codoped silica glasses

〇Koichi Kajihara¹, Shiori Yamaguchi¹, Kiyoshi Kanamura¹ (1.TMU)

Keywords:silica glass,rare-earth orthophosphate nanocrystal,UV absorption edge

Monolithic silica glasses containing nanocrystals of rare-earth (RE) orthophosphates (REPO₄, where RE = Y, La-Lu except Pm) were prepared by a cosolvent-free sol-gel method. Despite the large refractive index mismatch between the REPO₄ nanocrystals and the host silica glass, these glasses are highly transparent in the deep-ultraviolet (deep-UV, DUV) spectral region (~<300 nm) because Rayleigh scattering is suppressed by the small crystal size (~5-10 nm) and narrow size distribution. The UV absorption edge originates from the electronic transitions in PO₄ units for glasses containing Y³⁺, La³⁺, Gd³⁺, and Lu³⁺ ions and from the 4f-5d or charge transfer transition for glasses containing other RE³⁺ ions with partially filled 4f shells.