Quantitative determination of the thickness of ferroelectric domain walls using weak beam transmission electron microscopy

We present a new method for the quantitative determination of the thickness of ferroelectric domain walls using transmission electron microscopy in combination with image simulation. When inclined domain walls are imaged using a weakly excited beam, we observe well resolved thickness fringes across the boundary. By simulating these fringes and fitting them to the experimental images, we can extract a value for the domain wall thickness. The technique is applied to 90° domain walls in ferroelectric PbTiO3. The domain wall thickness is found to be 2.15 nm at room temperature. Our results are compared with values obtained by other techniques such as high-resolution transmission electron microscopy and electron holography.