铪铁双掺铌酸锂晶体的光折变参量研究  

Study on the Photorefractive Parameters of Lithium Niobate Crystals Doped with Fe and Hf

作　　者：师丽红 申绪男 阎文博[3] SHI Lihong;SHEN Xunan;YAN Wenbo(Department of Physics,Tianjin Chengjian University,Tianjin 300384,China;China Electronics Technology Lishen Group Co.,Ltd.,Tianjin 300381,China;State Key Laboratory of Reliability and Intelligence of Electrical Equipment,School of Materials Science and Engineering,Hebei University of Technology,Tianjin 300130,China)

机构地区：[1]天津城建大学理学院,天津300384 [2]中电科能源有限公司,天津300381 [3]河北工业大学材料科学与工程学院,电工装备可靠性与智能化国家重点实验室,天津300130

出　　处：《人工晶体学报》2023年第3期436-441,451,共7页Journal of Synthetic Crystals

摘　　要：本文研究了铪铁双掺铌酸锂(LN∶Fe,Hf)晶体的衍射效率随光栅写入角度的变化曲线,并对该关系曲线进行了拟合分析,发现超阈值的铪铁双掺铌酸锂晶体的体光生伏打系数κ值相比于单掺铁铌酸锂晶体大幅增加。造成κ值变化的原因可能是由于铪离子的掺入消除了晶体中存在的本征缺陷,而晶格环境的完美化使得留在锂位的铁离子的光生伏打系数大幅上升。此外,实验结果还表明超阈值的铪铁双掺铌酸锂晶体中参与光折变的缺陷中心浓度约为14.5 ppm(1 ppm=10-6),即约有4.8%的铁离子仍然“残存”在锂位中,而这些铁离子可以引起足够强的光折变效应,成为主导铌酸锂晶体光折变性能的缺陷中心。此外,还从杂质缺陷-氢氧根基团角度讨论了铁离子晶格占位的可能性。In this paper,the diffraction efficiency as a function of grating writing angle in LN∶Fe,Hf crystals was studied,and the relationship curve was fitted and analyzed.It is found that the bulk photovoltaic coefficientκincreases significantly when the Hf-doping concentration exceeds the threshold.The dramatic increase of the coefficientκto the fact that the Hf-doping eliminates the intrinsic defects in the crystal and the perfection of the lattice environment enhances the photovoltaic coefficient k of the Fe ions remaining at Li sites.The experimental results also show that the concentration of photorefractive centers is about 14.5 ppm(1 ppm=10-6)in LN∶Fe,Hf crystals,that is,4.8%of the Fe ions still“remain”in the Li site even though the Hf-doping concentration already exceeds the threshold,and that these Fe ions can cause sufficiently strong photorefractive effect and become the dominant photorefractive centers in the LN crystal.In addition,the possibility of Fe ion occupation in LN lattice from the perspective of impurity-hydroxyl defect complex was discussed.

关 键 词：铌酸锂 光折变 杂质缺陷 缺陷基团 氢氧根振动 本征缺陷 

分 类 号：TQ131.11[化学工程—无机化工] O734[理学—晶体学]