Synthesis of Hydrated Praseodymium, Samarium, Gadolinium and Dysprosium Carbonates

• 作 者: 柳松 马荣骏
• 机 构: College of Chemistry South China University of Technology,Changsha Research Institute of Mining and
• 出 处: Journal of Rare Earths
• 发表日期: 2006年S2期
• 关键词: carbonate spherical ammonium bidentate shaped saturated hydrolysis precipitate s

Crystalline hydrated praseodymium, samarium, gadolinium and dysprosium carbonates were synthesized using ammonium bicarbonate as precipitant. The praseodymium, samarium, gadolinium and dysprosium carbonates prepared are hydrated normal carbonates and the structure and properties were investigated by XRD, SEM, TG and IR techniques. The praseodymium carbonate consists of plate shaped crystals, and samarium, gadolinium and dysprosium carbonates consist of spherical aggregates of crystallites. The structure of the praseodymium carbonate is closely related to those of lanthanite type rare earth carbonates, and the structure of the samarium, gadolinium and dysprosium carbonates is closely related to those of tengerite type rare earth carbonates in the literature. The IR data for the praseodymium, samarium, gadolinium and dysprosium carbonates show the presence of two different carbonate groups (bidentate and unidentate carbonates) in the unit cell. In the process of thermal decomposition of the praseodymium, samarium and gadolinium carbonates to oxide, the intermediate phase was detected, but for dysprosium carbonate no stable intermediate was detected.

Crystalline hydrated praseodymium, samarium, gadolinium and dysprosium carbonates were synthesized using ammonium bicarbonate as precipitant. The praseodymium, samarium, gadolinium and dysprosium carbonates prepared were hydrated normal carbonates and the structure and properties were investigated by XRD, SEM, TG and IR techniques. praseodymium carbonate consists of plate shaped crystals, and samarium, gadolinium and dysprosium carbonates consist of spherical aggregates of crystallites. The structure of the praseodymium carbonate is closely related to those of lanthanite type rare earth carbonates, and the structure of the samarium, gadolinium and dysprosium The IR data for the praseodymium, samarium, gadolinium and dysprosium carbonates show the presence of two different carbonate groups (bidentate and unidentate carbonates) in the unit cell. In the process of thermal decomposition of the praseodymium, samarium and gadolinium carbonates to oxide, the intermediate phase was detected, but for dysprosium carbonate no stable intermediate was detected.