富铅配料合成PbI_2多晶及其熔体分层研究

Synthesis of PbI_2 Polycrystal with Excessive Pb and Its Immiscibility of Melt

富Pb配料、采用两温区气相输运法合成了单相的PbI2多晶材料,实验中出现熔体分层的现象。对合成结果的X射线衍射分析(XRD)和能量色散X射线微区分析(EDX)结果表明:富余的Pb沉积于石英安瓿的底部,与合成的单相PbI2多晶材料分离。根据富Pb配料的范围,结合文献的实验数据,可以确定在Pb-I相图中存在一个新的液相分层区域L2+L3,该区域对PbI2多晶合成和晶体生长具有指导作用。以合成的单相PbI2多晶为原料,采用垂直布里奇曼法生长出了尺寸为15mm×30mm、外观完整、呈桔红色的PbI2晶体。

Single-phase PbI2 polycrystalline material for single crystal growth was synthesized directly from highly pure Pb and 12 with excessive Pb, by two-temperature vapor-transporting method, and there is an immiscible phenomenon of two melts in the synthesis experiment. XRD analysis and EDX microanalysis indicate that the excessive Pb precipitates to the bottom of synthesis ampoule and separates from singlephase Phi2 polycrystal. Considering the observed immiscible phenomenon and the data given in paper, it is able to confirm that there is a new immiscible region L2 ＋ L3 in Pb-I phase diagram, which is very important to Pbi2 polycrystal synthesis and single crystal material synthesized by this method, intact and translucent was grown by vertical Bridgman method. growth. Using single-phase PbI2 single crystal with size Key words： excessive Pb; polycrystal synthesis ; immiscibility of melt; crystal growth PbI2 polycrystalline of φ15mm×30mm was grown by vertical Bridgman method.