A new approach to lattice parameter measurements using dynamic electron diffraction and pattern matching

We describe a new approach based on pattern matching for lattice parameter measurements using convergent beam electron diffraction (CBED). Theoretical CBED patterns are calculated using the Bloch wave method. Both experimental and theoretical patterns are processed to enhance the geometric features, and then compared using correlation. By including the dynamic and thickness effects in the simulation, the method is general. It can be applied to both small and large unit cell crystals and zone-axis and off-zone axis orientations. Applications to SiC 4H and Cu
2
O show that the method is highly accurate.