Sintering and grain growth in SiO2 doped Nd:YAG

✍ Scribed by Sujarinee Kochawattana; Adam Stevenson; Sang-Ho Lee; Mariola Ramirez; Venkatraman Gopalan; John Dumm; Vida K. Castillo; Gregory J. Quarles; Gary L. Messing

• Book ID: 104022846
• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 667 KB
• Volume: 28
• Category: Article
• ISSN: 0955-2219
• DOI: 10.1016/j.jeurceramsoc.2007.12.006

✦ Synopsis

Densification and grain growth in pure YAG, SiO 2 doped YAG and SiO 2 doped Nd:YAG were explored. The activation energy for densification (235 kJ/mol) in pure YAG is lower than that of grain growth (946 kJ/mol) which is unusual in ceramic systems. Consequently, pure YAG sinters to near full density (>99.9%) at 1700 • C with little grain growth (1.2 m average grain size). The remaining large pores (radius > 2 m) were determined to be thermodynamically stable because their coordination number with grains was >6. The stability of these pores underscores the importance of powder processing and forming in fabricating transparent YAG. SiO 2 doped YAG sinters to near full density 100 • C lower than pure YAG because SiO 2 enables liquid phase sintering and the removal of large pores. The addition of Nd 2 O 3 further enhances both densification and grain growth at temperatures below 1700 • C. Above 1700 • C higher concentrations of Nd 3+ suppressed grain growth, possibly due to solute drag.