Annealing induced discoloration of transparent YAG ceramics using divalent additives in solid-state reaction sintering |
| |
Affiliation: | 1. School of Computer Science and Technology, China University of Mining and Technology, Xuzhou, 221116, China;2. Key Laboratory of Intelligent Information Processing, Institute of Computing Technology, Chinese Academy of Sciences, Beijing, 100190, China;3. School of Computer and Software, Nanjing University of Information Science and Technology, Nanjing, 210044, China |
| |
Abstract: | Tetraethyl orthosilicate (TEOS) was commonly served as a sintering additive to promote the densification of transparent Y3Al5O12 (YAG) ceramics. However, Si4+ that decomposed from TEOS would restrain the conversion of dopants into a higher valence state (e.g., Cr3+ → Cr4+). In this study, by using divalent sintering additives (CaO and MgO), the colorless and highly transparent YAG ceramics (T = 84.6%, at 1064 nm) were obtained after vacuum sintering at 1840 °C for 8 h and without subsequent annealing in air. An absorption peak centered at ~320 nm was observed before annealing, and it extended to ~550 nm after annealing at 1450 °C for 10 h in air. A discoloration phenomenon occurred and more scattering centers were observed with the formation of new Mg/Ca2+F+] color centers. Air annealing did not improve the optical quality of the as-fabricated YAG ceramics with divalent dopants as sintering additives, owing to the formation of scattering centers. |
| |
Keywords: | Transparent ceramics Annealing YAG Sintering additives Optical property |
本文献已被 ScienceDirect 等数据库收录! |
|