水热前驱溶液pH值对Sm_2O_3微晶相组成及显微结构的影响

Influences of precursor pH value on the phase and microstructure of Sm_2O_3 microcrystallites prepared by hydrothermal method

以SmCl3.6H2O和NaOH为起始原料,采用水热法可控制备了Sm2O3微晶.利用X-射线衍射仪(XRD)、扫描电子显微镜(SEM)分别对产物的物相和形貌进行了表征.结果表明:在水热条件下,反应温度为200℃,前驱溶液pH为9时,水热产物主晶相为Sm2O3,杂相为Sm(OH)2Cl,呈现细棒状结构.在800℃下煅烧,保温1h均可得到纯的Sm2O3立方相微晶.随着pH值的增大,所制备的Sm2O3微晶的形貌变成规则的棒状结构,当pH为9时,棒状结构尺寸约为0.2～0.3μm.

Sm2O3 microcrystallines with controllable morphologies were prepared by hydro- thermal method using SmCl3· 6H2 O and NaOH as raw materials. The phase and morpholo- gy of as-prepared samples were characterized by X-Ray Diffraction （XRD）, Scanning Electron Microscope （SEM）. Results indicate that the main phase Sm2O3 and another phase Sm （OH）2Cl can be obtained by a hydrothermal method at 200 ℃ within pH=9 with thin rod like structure. Pure cubic Sm2 O3 microcrystallines can be achieved by firing the precursor at 800 ℃ for 1 h. As the pH value increases,the morphology of products changes to regular rod- like structure,and the Sm2O3microcrystallines sizes are in the range 0.2-0.3μm at pH= 9.