观察测量了不同生长速度(相应于不同降温速度)自发成核生长的Yb∶YAl3(BO3)4晶体形貌。粒度较大(>2mm)的晶体不管降温速度快慢形态都很简单，只发育六方柱｛1120｝和菱面体｛1011｝；粒度较小(<2mm)的晶体形态随降温速度增快而变复杂，发育一些罕见的高指数晶面。说明在生长速度较快的条件下，在晶体生长早期，一些高能面发育，在晶体生长后期已尖灭了，晶体生长的大部分时间是在低能面｛1120｝和｛1011｝上进行的。对比了不同生长条件下晶面的粗糙度，随着降温速度的增快，六方柱面｛1120｝和菱面体面｛1011｝由光滑变粗糙，顶面｛0001｝永远是粗糙的。从晶体结构上定性地探讨了3种晶面的杰克逊因子α及生长机理
The morphologies of Yb∶YAl3(BO3)4 crystals related to the growth rates(corresponding to the rates of decreasing temperature)are observed.These small crystals were obtained from spontaneous nucleation based on different rates of decreasing temperature.The crystals with the size larger than 2mm have simple morphology composed by ｛1120｝ and ｛1011｝only,which is independent from the rate of decreasing temperature.But the crystals with the size smaller than 2mm have complicated morphologies composed by some rare crystal forms when the rate of decreasing temperature is high.It is reflected that some faces with high surface energy developed in the early growth stage when growth rate is high,but these faces disappeared soon during further growth.That means the crystals grow mainly on the low energy faces:｛1120｝ and ｛1011｝.The surface roughness of the crystals is different,which is corresponding to different growth rates.At high growth rate,the morphologies of ｛1120｝ and ｛1011｝ are changed from smooth to rough,and that of ｛0001｝ keeps rough.From the crystal structure,we qualitatively discussed the Jackson Factor α and the growth mechanisms of these three kinds of faces.
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