Analysis of growth kinetics and impact of NH ₃ on the morphology evolution of hexagonal-prism shaped Y ₄ O(OH) ₉ NO ₃ /Y ₂ O ₃ single crystals

The effect of NH ₃ on the morphology evolution of single crystalline hexagonal-prism like Y ₄ O(OH) ₉ NO ₃ and Y ₂ O ₃ has been systematically investigated, as a function of reaction time, by using a combination of powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). Rational control over the morphology has been achieved by the choice of suitable electrolytes like NaNO ₃ , KNO ₃ , NH ₄ NO ₃ , KCl and NH ₄ Cl in the presence of NH ₄ OH. We report that the cross-sectional geometry of hydrothermally grown one-dimensional Y ₄ O(OH) ₉ NO ₃ crystals can be tuned from spherical to hexagonal-prism like shape by introducing a particular reagent like NH ₄ NO ₃ in the presence of NH ₄ OH. An ‘oriented attachment’ mediated growth process takes place along with the ‘dissolution-recrystallization’ route which eventually resulted in the generation of the single crystals with hexagonal-prism like morphology.