Growth and internal bias field of l-lysine-doped triglycine sulfate (LLysTGS)

Abstract

Single crystals of l-lysine-doped TGS (LLysTGS) have been prepared from the aqueous solutions with various concentrations of dopant. The variation of crystal shape and the distribution of internal bias field E b were examined. The growth rate in the + b side of seed crystal is higher than in the − b side. Therefore, the mirror plane m normal to the ferroelectric b-axis disappears in the crystal morphology and the doped crystal shows a habit of polar symmetry 2. The degree of the asymmetry increases with the concentration of l-lysine. The effect of l-lysine-doping on the crystal shape is closely resembled to the l-alanine-doping (LAlaTGS). The internal bias field E b caused by the doping depends on the growth sector. The distribution of E b also shows the symmetry 2. There exist both sectors with positive E b and negative E b. The development of E b in LLysTGS crystal is distinctly different from that in LAlaTGS.