关于MgF_2氧化问题的Rietveld全谱拟合研究

Study of oxidization of MgF_2 by the rietveld method of whole pattern fitting

用Rietveld全谱拟合方法研究了MgF2 在大气中随着温度的升高转变为MgO的过程 ,确定了其转变条件、精化了转变前后的相关参数。结果表明 :纯MgF2 在大气中于 80 0℃左右开始向MgO转变 ,Ag加MgF2 与单纯MgF2 在促成MgO的生成方面无异 ,MgF2 在 70 0℃左右存在一个异常膨胀区 ,MgF2

The transformation of MgF 2 to MgO with increasing temperature is investigated by Rietveld structure refinement.The condition of MgF 2changing into MgO has been determined,structural parameters at different temperatures refined.The refined results show that pure MgF 2 in air begins to change into MgO at 800℃ or so ,structural parameters of MgF 2 unusually change with increasing temperature and F atom'site always tends to turn round Mg'.