precursors. In-situ fluorination was performed by decomposition of a fluorine containing organic compound named 1,1,1-trifluoro-5-methyl-2,4-hexanedione when sintering the as-prepared xerogel to produce crystallized samples. Both to insure complete departure of organic residues as well as to avoid any oxidation into oxyfluoride, annealing treatment was carried out under fluorine atmosphere. Free-oxygen content
基于溶胶-凝胶法的软合成路线用于从醇盐前体制备稀土四
氟化物粉末。当烧结制备的干凝胶以产生结晶样品时,通过分解名为
1,1,1-三氟-5-甲基-2,4-己二酮的含
氟有机化合物来进行原位
氟化。为了确保有机残留物完全离开以及避免氧化成
氟氧化物,都在
氟气氛下进行了退火处理。红外和拉曼光谱法证明了所得样品中的游离氧含量。X射线吸收光谱(XAS)和19 F核磁共振(NMR)研究表明,在300°C热处理的样品已经结晶,但在LiGdF 4中完全结晶。和LiYF 4,需要在550°C下进行热处理。通过扫描电子显微镜(
SEM)分析粉末形态的温度依赖性。