AFM Investigation on Step Bunching on (100) Face of KDP Crystal

doi:10.3724/SP.J.1077.2010.01191

Abstract

Abstract: The dependence of growth rate of (100) face of KDP crystal on supersaturation was measured using the laser polarization interference technique. Morphologies of both elementary steps and macrosteps were investigated by using AFM technique at a serial of supersaturation. Furthermore, the bunching process as well as the influence of supersaturation on bunching process was analyzed according to the AFM results. The results show that at the supersaturation of 1.8%, elementary steps are in priority on (100) face, whose height is 0.366 nm, equivalent to half of the unit cell. When the supersaturation is increased, elementary steps begin bunching together. At the initial bunching stage, the step height and step width are increased. With a rise of supersaturation, more elementary steps participate in the bunching process, and the velocity of the macrosteps increasease as well. At the same time, the slops of the macrosteps reach stable ultimately.

Key words: KDP, step bunching, AFM, crystal growth

CLC Number:

O781

DING Jian-Xu, WANG Sheng-Lai, MU Xiao-Ming, YU Guang-Wei, XU Xin-Guang, SUN Yun, LIU Wen-Jie. AFM Investigation on Step Bunching on (100) Face of KDP Crystal[J]. Journal of Inorganic Materials, 2010, 25(11): 1191-1194.

References

[1] De Yoreo J J, Land T A, Lee J D. Limits on surface vicinality and growth rate due to hollow dislocation cores on KDP (101) face. Physical Review Letters, 1997, 78(23): 4462-4465. [2] Alexandru H V, Berbecaru C, Grancea A, et al. KDP prismatic faces: kinetics and the mechanism of their growth from solutions. Journal of Crystal Growth, 1996, 166(1): 162-166. [3] Alexandru H V. KDP kinetics and dislocation efficiency of growth. Journal of Crystal Growth, 1999, 205(1/2): 215-222. [4] Land T A, DeYoreo J J, Martin T L, et al. A comparison of growth hillock structure and step dynamics on KDP {100} and {101} surfaces using force microscopy. Crysallog. Rep., 1999, 44(4): 655-666. [5] Chernov A A. Step bunching and solution flow. J. Optoelectron. Adv. Mater., 2003, 5(3): 575-587. [6] Coriell S R, Murray B T, Chernov A A, et al. Step bunching on a vicinal face of a crystal growing in a flowing solution. Journal of Crystal Growth, 1996, 169(4): 773-785. [7] Terry A L, Tracie L M, Sergey P, et al. Recovery of surfaces from impurity poisoning during crystal growth. Nature, 1999, 399: 442-445. [8] Sendhil K P, Pui S C, Reginald B H. Impurity effects on the growth of molecular crystals: experiments and modeling. Advanced Powder Technology, 2008, 19(5): 459-473. [9] Masuda M, Nishinaga T. Macrostep formation and growth condition dependence in MBE of GaAs on GaAs (111) B vicinal surface. Journal of Crystal Growth, 1999, 198-199(2): 1098-1103. [10] Ren H W, Shen X Q, Nishinaga T. In situ observation of macrostep formation on misoriented GaAs (111) B by molecular beam epitaxy. Journal of Crystal Growth, 1996, 166(4): 217-221. [11] Sangwal K, Torrent-Burgues J, Sanz F, et al. Atomic force microscopic study of step bunching and macrostep formation during the growth of L-arginine phosphate monohydrate single crystals. Journal of Crystal Growth, 1997, 172(10): 209-218. [12] Xie M H, Leung S Y, Tong S Y. What causes step bunching-negative Ehrlich–Schwoebel barrier versus positive incorporation barrier. Surface Science .2002, 515(1): L459-L463. [13] Liu B, Fang C S, Wang S L, et al. In situ measurement of growth kinetics of {100} faces of KDP crystal in the presence of polyphosphate impurities. Crystal Research and Technology, 2009, 43(7): 700-708. [14] Burton W K, Cabrera N, Frank F C. The growth of crystals and the equilibrium structure of their surfaces. Royal Soc. London Philos. Trans., 1951, 243(866): 299-358 [15] Thomas T N, Land T A, Martin T, et al. AFM investigation of step kinetics and hillock morphology of the (100) face of KDP. Journal of Crystal Growth, 2004, 260(3/4): 566-579.