Determination of the thickness of the ferroelectric domain boundary in triglycine sulphate by X-ray topography

A new method is presented for the determination of the thickness of a kinematically diffracting lamella contained in a region of perfect crystal diffracting X-rays dynamically. The method has been applied to the case of a kinematically diffracting ferroelectric domain boundary in a crystal of triglycine sulphate. The thickness of the region diffracting X-rays kinematically when the 140 planes were used with MoKα radiation is found to be 0.75 ± 0.25 μm and the domain boundary fault vector has a length ∼ 1.5 × 10−2 Å.