Picometer Scale Differences of Lattice Spacing In TEM Images

There are many applications in modern science in which a very precise knowledge of atom spacings i.e. lattice parameters is crucial. These include multi layer hetero structures in device manufacturing and core-rim nano particles, for example. In general it is interesting to know the change in spacings – or the strain in the proximity of a lattice defect or a coherent interface between two different substances. From the knowledge of the spacings e.g. relaxation processes can be studied. Mathematical transforms intermediate between direct and reciprocal space make possible digital darkfield strategies for mapping strain relaxation around interfaces and dislocations [1-5]. Here we examine applications to the measurement of lattice parameter differences between adjacent phases.