Effect of rare-earth oxide additives on transparency and fluorescence of α-SiAlON ceramics. Issue 16 (15th August 2022)

• Record Type: Journal Article
• Authors: Aminaka, Kohei; Tatami, Junichi; Iijima, Motoyuki; Takahashi, Takuma; Yahagi, Tsukaho
• Is Part Of: Ceramics international. Volume 48:Issue 16(2022)
• Page Start: 23195
• Page End: 23205
• Publication Date: 2022-08-15
• Subjects: D sialon -- C optical properties -- A sintering -- B microstructure-final -- Main text; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.04.302
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Recently, novel transparent and fluorescent materials are in demand for various optical applications such as lasers, scintillators, and solid-state lighting. α-SiAlON, which has excellent thermal and mechanical properties, also exhibits photoluminescence depending on the stabilized doped rare-earth ions. Its transparency and fluorescence depend on the rare-earth oxide added as a raw material, particularly in conventional powder processing. In this study, we fabricated α-SiAlON ceramics by adding various rare-earth oxides to elucidate their effects on the transparency and fluorescence of these ceramics. High-transparency α-SiAlON ceramics were fabricated by adding rare-earth oxides whose rare-earth ions have small ionic radii: Y2 O3, Ho2 O3, Er2 O3, Tm2 O3, Yb2 O3, and Lu2 O3 . Because the fraction of α-SiAlON was high, the relative density was high, and the microstructure was composed of fine grains. In particular, α-SiAlON ceramics prepared by adding Ho2 O3 showed lower light scattering than the other fabricated α-SiAlON ceramics because of the smaller α-SiAlON grains, resulting in higher in-line transmittance (48% at 600 nm). Furthermore, these transparent α-SiAlON ceramics exhibited fluorescence corresponding to the activated rare-earth ions: Ho 3+, Er 3+, Tm 3+, and Yb 3+ or Yb 2+ .