Freeze-dried nanometric neodymium-doped YAG powders for transparent ceramics
Résumé
Nanometric neodymium-doped yttrium aluminium garnet (YAG) has been synthesised from freeze-dried precursors. The productswere calcined between 900 ◦C and 1200 ◦C under flowing oxygen. Powder morphologies were observed by TEM, SEM and laser granulometer. The oxides had small crystallite size. The best sinterability under vacuum at 1700 ◦C for 3h was obtained for precursors with the lowest amount of organic impurities as indicated by IR measurements. Hot isostatic pressing at 1700 ◦C in 160MPa of argon was applied to complete the sintering. Under these conditions, Nd:YAG ceramics with very good transmittance were obtained.