Experimental Study on Internal Bias Electric Field of Nominally Undoped and Doped Lithium Niobate Crystals

Abstract

Abstract: Internal bias electric field in the lithium niobate (LN) crystal has a direct impact to the ferroelectric, electro-optic, and nonlinear effects of the crystal and the associated applications. A method to measure this field was proposed, and such a measurement in congruent lithium niobate (CLN) crystals, near-stoichiometric lithium niobate (nSLN) crystals, and doped LN crystals was performed. The results show that the internal bias electric field in the CLN crystal (reaching 2.53 kV/mm) is the largest among the three cases. Compared with the CLN crystal, this field greatly reduces in the nSLN crystals, and can be even lower by two orders of magnitudes for those grown by the lithium-rich melts method followed by vapor transport equilibration (VTE) treatment. In the doped LN crystals, the internal bias electric fields for the cases of 6.5% (mole fraction) Mg and 7% (mole fraction) Zn doping are 4 and 6 times smaller than that in the CLN crystal, respectively. The reason for causing the difference in the two doped cases was briefly discussed.

Key words: lithium niobate crystal, internal bias electric field, nominally undoping, doping, intrinsic defect, threshold concentration

CLC Number:

WU Jing, LI Qinglian, ZHANG Zhongzheng, YANG Jinfeng, HAO Yongxin, LI Jiaxin, LIU Shiguo, ZHANG Ling, SUN Jun. Experimental Study on Internal Bias Electric Field of Nominally Undoped and Doped Lithium Niobate Crystals[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2022, 51(4): 571-578.

References

[1] 高博锋,任梦昕,郑大怀,等.铌酸锂的耄耋之路:历史与若干进展[J].人工晶体学报,2021,50(7):1183-1199.
GAO B F, REN M X, ZHENG D H, et al. Long-lived lithium niobate: history and progress[J]. Journal of Synthetic Crystals, 2021, 50(7): 1183-1199(in Chinese).
[2] WANG K, GAO M, YU S, et al. A compact and high efficiency intracavity OPO based on periodically poled lithium niobate[J]. Scientific Reports, 2021, 11: 5079.
[3] ZHANG M F, GUO H X, ZHANG H L, et al. A study on the disk-type piezoelectric transformer of Mg:Ln single crystal[J]. Advanced Materials Research, 2010, 105/106: 278-281.
[4] 郑大怀,吴婧,商继芳,等.电光调Q晶体研究进展[J].中国科学:技术科学,2017,47(11):1139-1148.
ZHENG D H, WU J, SHANG J F, et al. Progress on electro-optic crystals for Q-switches[J]. Scientia Sinica, 2017, 47(11): 1139-1148(in Chinese).
[5] 窦飞飞,杨金凤,刘小伟,等.中红外光参量振荡器用周期极化晶体的研究进展[J].硅酸盐通报,2011,30(3):608-614.
DOU F F, YANG J F, LIU X W, et al. Research progress of periodically poled crystals for MIR-QPM-OPO[J]. Bulletin of the Chinese Ceramic Society, 2011, 30(3): 608-614(in Chinese).
[6] KIM S, GOPALAN V, GRUVERMAN A. Coercive fields in ferroelectrics: a case study in lithium niobate and lithium tantalate[J]. Applied Physics Letters, 2002, 80(15): 2740-2742.
[7] GOPALAN V, GUPTA M C. Observation of internal field in LiTaO₃ single crystals: its origin and time-temperature dependence[J]. Applied Physics Letters, 1996, 68(7): 888-890.
[8] ASHKIN A, BOYD G D, DZIEDZIC J M, et al. Optically-induced refractive index inhomogeneities in LiNbO₃ and LiTaO₃[J]. Applied Physics Letters, 1966, 9(1): 72-74.
[9] CHEN F S, LAMACCHIA J T, FRASER D B. Holographic storage in lithium niobate[J]. Applied Physics Letters, 1968, 13(7): 223-225.
[10] GOPALAN V, GUPTA M C. Origin and characteristics of internal fields in LiNbO₃ crystals[J]. Ferroelectrics, 1997, 198(1): 49-59.
[11] GOPALAN V, MITCHELL T E, FURUKAWA Y, et al. The role of nonstoichiometry in 180° domain switching of LiNbO₃ crystals[J]. Applied Physics Letters, 1998, 72(16): 1981-1983.
[12] KURIMURA S, SHOJI I, TAIRA T, et al. Coercive field dependence on Mg concentration in MgO:LiNbO₃[C]//Technical Digest. Summaries of papers presented at the Conference on Lasers and Electro-Optics. Postconference Technical Digest (IEEE Cat. No.01CH37170). May 11, 2001. Baltimore, MD, USA. IEEE, 2001.
[13] CHEN Y L, YAN W G, GUO J, et al. Effect of Mg concentration on the domain reversal of Mg-doped LiNbO₃[J]. Applied Physics Letters, 2005, 87(21): 212904.
[14] 孔勇发,刘士国,刘宏德,等.四价掺杂铌酸锂晶体[J].红外与毫米波学报,2009,28(3):181-183+187.
KONG Y F, LIU S G, LIU H D, et al. Tetravalent ions doped lithium niobate crystals[J]. Journal of Infrared and Millimeter Waves, 2009, 28(3): 181-183+187(in Chinese).
[15] 袁烨.铌酸锂、钽酸锂超晶格:制备技术优化及其应用研究[D].南京:南京大学,2012.
YUAN Y. Superlattices of lithium niobate and lithium tantalate: preparation optimization and application study[D]. Nanjing: Nanjing University, 2012.(in Chinese)
[16] 杨金凤,黄存新,孙军,等.铌酸锂晶体锂含量的精确测量研究[J].人工晶体学报,2014,43(4):738-742.
YANG J F, HUANG C X, SUN J, et al. Study on precise determination of lithium content in the LiNbO₃ crystals[J]. Journal of Synthetic Crystals, 2014, 43(4): 738-742(in Chinese).
[17] LERNER P, LEGRAS C, DUMAS J P. Stoichiometry of single-crystal of lithium metaniobate[J]. Journal of Crystal Growth, 1968, 3: 231-235.
[18] IYI N, KITAMURA K, IZUMI F, et al. Comparative study of defect structures in lithium niobate with different compositions[J]. Journal of Solid State Chemistry, 1992, 101(2): 340-352.
[19] YAN W B, KONG Y F, SHI L H, et al. The relationship between the switching field and the intrinsic defects in near-stoichiometric lithium niobate crystals[J]. Journal of Physics D: Applied Physics, 2006, 39(1): 21-24.
[20] VOLK T, MAXIMOV B, CHERNAYA T, et al. Photorefractive properties of LiNbO₃:Zn crystals related to the defect structure[J]. Applied Physics B, 2001, 72(6): 647-652.
[21] 邓家春,温金珂,王华馥.掺锌铌酸锂(LiNbO₃:Zn)晶体的物性测量[J].南开大学学报(自然科学版),1994,27(2):47-51.
DENG J C, WEN J K, WANG H F. Measurement of physical properties in zinc-doped lithium niobate (LiNbO₃:Zn)[J]. Acta Scientiarum Naturalium Universitatis Nankaiensis, 1994, 27(2): 47-51(in Chinese).
[22] 付博,张国权,刘祥明,等.掺杂对铌酸锂晶体非挥发全息存储性能的影响[J].物理学报,2008,57(5):2946-2951.
FU B, ZHANG G Q, LIU X M, et al. Influence of dopants on nonvolatile holographic storage in lithium niobate[J]. Acta Physica Sinica, 2008, 57(5): 2946-2951(in Chinese).
[23] GRABMAIER B C, WERSING W, KOESTLER W. Properties of undoped and MgO-doped LiNbO₃; correlation to the defect structure[J]. Journal of Crystal Growth, 1991, 110(3): 339-347.
[24] IYI N, KITAMURA K, YAJIMA Y, et al. Defect structure model of MgO-doped LiNbO₃[J]. Journal of Solid State Chemistry, 1995, 118(1): 148-152.
[25] LIU J J, ZHANG W L, ZHANG G Y. Defect chemistry analysis of the defect structure in Mg-doped LiNbO₃ crystals[J]. Physica Status Solidi (a), 1996, 156(2): 285-291.
[26] 孔勇发,李兵,陈云琳,等.掺镁铌酸锂晶体抗光折变微观机理研究[J].红外与毫米波学报,2003,22(1):40-44.
KONG Y F, LI B, CHEN Y L, et al. Syudy on the micro-mechanism of Mg-doped lituium niobate crystals against photorefraction[J]. Journal of Infrared and Millimeter Waves, 2003, 22(1): 40-44(in Chinese).