On the measurement of lattice parameters in a collection of nanoparticles by transmission electron diffraction

Improved accuracy in transmission electron diffraction measurements of interplanar spacings can be achieved by adding to the camera constant a term proportional to the square of the diffraction ring radius. A statistical technique using all of the diffraction rings yielded a precision better than 0.05% when measuring the lattice parameter of copper nanoparticles. Gold was used as an internal reference for copper by vapor depositing gold and copper on opposite sides of a thin amorphous carbon film. The source of the squared-radius term is consistent with distortions associated with the magnetic field of the post-objective lenses.