【摘要】 通过优选合适的化学原料,用坩埚下降法生长出了无宏观缺陷的Zn∶Fe∶LiNbO3(Zn∶Fe∶LN)单晶。生长的工艺参数是:用微凸生长界面生长,生长速度为1～3mm/h,温度梯度为20～30℃/cm。用X射线衍射及DTA对晶体进行了分析;测定了晶体的吸收光谱。结果表明:所有Zn∶Fe∶LN晶体中的Fe2+浓度沿生长方向增加;掺杂3%ZnO(摩尔分数)的Zn∶Fe∶LN单晶中的Fe2+浓度沿生长方向的变化量比掺杂6%ZnO的大。从坩埚下降法的温场特点、晶体的热处理过程、环境气氛,以及ZnO组分对Fe离子的排斥作用解释了产生Fe2+离子浓度变化的原因。更多还原

【Abstract】 Large sized LiNbO3 (LN) single crystals doped with Fe and Zn ions (Zn∶Fe∶LN) were prepared by the Bridgman method at the optimum growth conditions such as proper raw materials, sealed platinum crucibles, growth rate of 1—3 mm/h and convex solid-liquid interface with temperature gradient around 20—30 ℃/cm. The LN crystals obtained were characterized by means of XRD and DTA. The UV/VIS absorption spectra of crystals were measured. The results indicate that the concentration of Fe2+ ions in Zn∶Fe∶LN crystals increases along growth direction, and the Fe2+ ion concentration of Zn∶Fe∶LN crystals doped with 3% ZnO (molar fraction, same below) changes along the growth direction much more than doped with 6% ZnO. The reason for the concentration changes of Fe ions can be interpreted by the suppressing effect of ZnO for the incorporation of a Fe ions, thermal field of furnace, the thermal treatment for the crystals and the growth environment.更多还原