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通过透射光谱、x射线激发发射光谱 (XSL)的测试 ,研究了Bridgman法生长的几种不同 +3价离子掺杂钨酸铅晶体的发光性能 ,并利用正电子湮没寿命谱 (PAT)和x光电子能谱 (XPS)的实验手段 ,对不同钨酸铅晶体的微观缺陷进行研究 .实验表明 ,不同的 +3价离子掺杂 ,对钨酸铅晶体发光性能的改善不同 ,并使得晶体中正电子俘获中心和低价氧的浓度发生不同变化 .其中掺镧晶体的正电子俘获中心和低价氧浓度均上升 ,而掺钇和掺铋晶体的正电子俘获中心和低价氧浓度均下降 ,掺锑晶体则出现了正电子俘获中心浓度上升、低价氧浓度下降的情况 .提出 +3价离子在钨酸铅晶体中的掺杂作用机理并不相同 ,晶体中La3+ 将替代Pb2 + 的格位 ,Y3+ 和Bi3+ 将占据铅空位 ,而锑可以以Sb3+ 替代Pb2 + 格位和Sb5+ 替代W6 + 格位的两种形式存在
The emission properties of several different +3 valence doped lead tungstate crystals grown by Bridgman method were studied by transmission and X-ray emission spectroscopy (XSL). The positron annihilation lifetime (PAT) and x Photoelectron spectroscopy (XPS) experiments were carried out to study the microscopic defects of different lead tungstate crystals.The experimental results show that the different +3 valence ion doping can improve the luminescence properties of lead tungstate crystals differently, and make the positron The concentrations of trapping center and hypoxia vary with the concentration of lanthanum-doped positron-trapping center and low-level oxygen, while the concentrations of positron-trapping center and low-level oxygen of both y-doped and bismuth- Antimony crystals show a rise in the concentration of positron-trapping centers and a decrease in the oxygen concentration in the low-valent state. It is proposed that the doping mechanism of +3 valence ions in lead tungstate crystals is not the same. La3 + in the crystals will replace the lattice sites of Pb2 + , Y3 + and Bi3 + will occupy lead vacancies while antimony may exist in two forms, Sb3 + instead of Pb2 + and Sb5 + instead of W6 +