کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1793768 | 1023682 | 2009 | 6 صفحه PDF | دانلود رایگان |

Aiming at tailoring optical properties, the precipitation of LaF3 nano-crystals in LaF3–Na2O–Al2O3–SiO2 glass-ceramics is studied thoroughly on the nano-scale using advanced transmission electron microscopic techniques. Nano-sized phase-separation droplets enriched in lanthanum and silicon are formed already in the base glass. Within these less than 20 nm large droplets, LaF3 crystallizes upon heat treatment. The nano-crystallization mechanism revealed is self-limited since growth is restricted by the size of the droplets. An average crystallite size of around 12 nm is achieved with a narrow size distribution since the phase-separation droplets also contain silicon not incorporated into the growing crystal. Instead, excess silicon relocated to the periphery of the pre-existing phase-separation droplets forms a diffusion barrier around the LaF3 nano-crystals preventing further crystal growth and/or ripening.
Journal: Journal of Crystal Growth - Volume 311, Issue 18, 1 September 2009, Pages 4350–4355