The 17th American Conference on Crystal Growth and Epitaxy
in conjunction with
The 14th US Biennial Workshop on Organometallic Vapor Phase Epitaxy
and
The 6th International Workshop on Modeling in Crystal Growth
will be held together
August 9 - 14, 2009, Lake Geneva, Wisconsin
 
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Abstract Details:

Session:  Date:  Time:  Room:
ACCGE - Nanocrystals, Quantum Dots and Nanowires  08/11  15:30  Grand Ballroom A+B+C

Title:
Growth and properties of another new amino acid family NLO crystal --- LATF with high damage threshold
Authors:
Xu, Dong 1; Guang-hui , Zhang 1; Xiao-jing, Liu 1; Zhi-hua, Sun 1; Gui-hua, Sun 1; Xin-qiang, Wang 1
1State Key Laboratory of Crystal Materials
Abstract:
L-arginine phosphate monohydrate (LAP), discovered by Shandong University in 1983, is an important nonlinear optical (NLO) crystal with high conversion efficiency (>90%) and specially high damage thersold (63GW) used for harmonic frequency generation and phase conjugating mirrors for laser fusion experiments. HenceCthe behaviors of LAP crystal have attracted much attention. We have discovered that LAP crystal has larger specific heat than KDP and other NLO crystals, and paid more attention to the function of L-arginine phosphate in biology. L-arginine trifluoroacetate (LATF) crystal, as a novel L-arginine derivative, is another NLO crystal discovered by Shandong University in 2003, exhibiting high damage threshold. LATF belongs to the monoclinic system, P21 space group, powder SHG efficiencies is 2.5 times higher than that of KDP. Therefore, LATF crystal is a new valuable and potential NLO crystal material. Buck LATF and DLATF crystals with highly-optical quality have been grown from solution by using the temperature lowering method. The major factors that influence the stability of growth and quality of crystals have been systemically discussed in detail. The crystal structure of LATF shows optimizing the orientation of L-Arg, namely L-Arg and CF3COOH arrange in order. The optically active L-Arg with the asymmetrical guanidyl and carboxyl groups to combine with the alkyl radical possessing F3C tetrahedra of CF3COOH and forms the high nonlinearity of the crystal. The optical, thermal and electric properties of LATF crystal were investigated, and the influence of these properties on growth and applications were also discussed. The specific heat of LATF is larger than that of LAP and the thermal expansion coefficients of LATF are less anisotropic than that of LAP. Therefore, LATF crystal has a higher laser damage potential than LAP crystal. The surface morphology and growth mechanism of LATF crystals grown from various conditions were investigated using atomic force microscopy (AFM). Crystals were grown by the layer mode including dislocation-controlled mechanism and two-dimensional (2D) nucleation growth which dominates the crystal growth. The step height of elementary steps is about 0.64 nm. Growth of LATF crystals obtained from low temperature solvent evaporation method occurs in step trains. The step bunching is always introduced by foreign impurities or particles. The influence of defects on LATF crystal growth and properties were also analyzed.