[M-IS10] Interface- and nano-phenomena on crystal growth and dissolution

[MIS10-P05] Influence of Ammonium Nitrate on Crystallization of Norsethite from Aqueous Solution

*Itaru Echigo¹, Harutoshi Asakawa¹, Hiroshi Uneda, Ryuichi Komatsu¹ (1.Graduate School of Science and Technology for Innovation Yamaguchi University)

Keywords:Norsethite, Aqueous Solution Growth, Ammonium Nitrate

Since norsethite BaMg(CO₃)₂ has birefringence higher than previous piezoelectric and optical crystals, we expect that norsethite can be used as new acousto-optics andwavelength-conversion devices. However, solubility of norsethite is low and it is difficult to control supersaturation. Hence growth of norsethite is difficult. Then, we investigated effects of ammonium nitrate NH₄NO₃ on crystallization of norsethite from aqueous solution. With increasing NH₄NO₃, solubility of norsethite increased. When concentration of NH₄NO₃ reached to 1M, solubility of norsethite became 30 times larger than without the addition of NH₄NO₃.With further increasing NH₄NO₃, solubility of norsethite remained constant. Next, we measured induction periods of norsethite, when 1M NH₄NO₃ was added. Then, we could confirm norsethite just after mixed at 70^oC by XRD measurement only in the case of the addition of 1M NH₄NO₃. Thus, we revealed that the addition of NH₄NO₃ also accelerates norsethite crystallization. This study concluded that addition of NH₄NO₃ is valid for the growth of norsethite.