Observation of Cleavage Surface in Tri-Glycine Sulfate by Atomic Force Microscopy

Abstract

Step patterns on the (010) cleavage plane in triglycine sulfate (TGS) were investigated using a scanning probe microscopy (SPM). It was found that the interval of the step height is one half the lattice constant b, and the contrast of the friction image of the step pattern shows an 180° domain wall structure. It was concluded that the cleavage planes in the unit cell of TGS are located at 0 or 1/2 along the b-axis, depending on the direction of the spontaneous polarization. The time evolution of the step pattern was also discussed by assuming the molecular diffusion on the surface. The diffusion constant and the dead time were found to be about 1.7 × 10⁻¹³ cm²/sec and 30 minutes, respectively.

Keywords:

• 180° domain wall structure
• scanning probe microscopy
• atomic force microscopy
• friction force microscopy
• triglycine sulfate