摘要
本文根据偏光显微镜观察，把存在于立方氟化铅晶体中的包裹体分为三种类型：针状包裹体、板状包裹体和无规则形包裹体。根据ＥＤＳ成分分析和ＸＲＤ结构测定，认为针状包裹体的组成为铅的氧化物和氟氧化物，板状包裹体和无规则形包裹体为氟化铅的斜方相。针状包裹体是由于原料中的ＰｂＯ杂质引起组分过冷而造成氧化铅和氟氧化铅小颗粒的定向排列。如果氧化物杂质含量不是很高，则通过掺入过量脱氧剂、提高固液界面处的温度梯度和降低下降速度，可以比较有效地减少甚至消除晶体中的针状包裹体。
Based on the observation with polarizing microscope, the inclusions in cubic PbF 2 crystals are classified as three types:needle like, tabular and irregular shape inclusions.EDS and XRD analysis suggested that the needle like inclusions are lead oxide and lead fluoro oxide,another two types of inclusions are orthorhombic lead fluorides.The needle like inclusions are formed through constitutional supercooling due to the contamination of oxygen or lead oxide impurities in the raw materials.This type of inclusion could be avoided or reduced by doping with deoxidant,increasing temperature gradient near the interface between the crystal and the melt as well as slowing down the rate of crystal growth if the contents of oxide impurities are not very high.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
1998年第2期146-151,共6页
Journal of Synthetic Crystals
基金
国家自然科学基金
关键词
氟化铅晶体
包裹体
闪烁晶体
显微观察
PbF 2 crystal,inclusions,constitutional supercooling,scintillatior crystal
