TY - JOUR
T1 - Sintering and grain growth in SiO2 doped Nd:YAG
AU - Kochawattana, Sujarinee
AU - Stevenson, Adam
AU - Lee, Sang Ho
AU - Ramirez, Mariola
AU - Gopalan, Venkatraman
AU - Dumm, John
AU - Castillo, Vida K.
AU - Quarles, Gregory J.
AU - Messing, Gary L.
N1 - Funding Information:
This work was supported by VLOC Inc. through funds received from VLOC's prime contract #N66001-00-c-6008. S.K. is particularly grateful for the support of a Royal Thai Scholarship. We also thank E. Meuschke and Baikowski Malakoff Inc. for supplying the BA-15 alumina powder used in this study. The authors also wish to thank A. Ikesue for helpful conversations.
PY - 2008
Y1 - 2008
N2 - Densification and grain growth in pure YAG, SiO2 doped YAG and SiO2 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 μm average grain size). The remaining large pores (radius > 2 μm) 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. SiO2 doped YAG sinters to near full density 100 °C lower than pure YAG because SiO2 enables liquid phase sintering and the removal of large pores. The addition of Nd2O3 further enhances both densification and grain growth at temperatures below 1700 °C. Above 1700 °C higher concentrations of Nd3+ suppressed grain growth, possibly due to solute drag.
AB - Densification and grain growth in pure YAG, SiO2 doped YAG and SiO2 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 μm average grain size). The remaining large pores (radius > 2 μm) 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. SiO2 doped YAG sinters to near full density 100 °C lower than pure YAG because SiO2 enables liquid phase sintering and the removal of large pores. The addition of Nd2O3 further enhances both densification and grain growth at temperatures below 1700 °C. Above 1700 °C higher concentrations of Nd3+ suppressed grain growth, possibly due to solute drag.
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U2 - 10.1016/j.jeurceramsoc.2007.12.006
DO - 10.1016/j.jeurceramsoc.2007.12.006
M3 - Article
AN - SCOPUS:40649093277
SN - 0955-2219
VL - 28
SP - 1527
EP - 1534
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
IS - 7
ER -