Chemical transformations of basic yttrium nitrates during ultrasonic-hydrothermal treatment

We studied how hydrothermal treatment per se or combined ultrasonic-hydrothermal treatment affects the micromorphology and phase composition of yttrium hydroxonitrates. We show that ultrasonication during the hydrothermal treatment of yttrium hydroxonitrate suspensions of the bulk composition Y(OH) 2.53 (NO 3 ) 0.47 · 0.16H 2 O produces yttrium oxohydroxonitrate crystals of the composition YO 0.25 (OH) 2.25 (NO 3 ) 0.25 .