Ultra-high resolution with off-axis STEM holography.

It has previously been demonstrated that the scheme of Rodenburg and colleagues for deriving ultra-high resolution images from arrays of nanodiffraction patterns recorded in a scanning transmission electron microscopy instrument is capable of producing reconstructed images with an improvement in resolution by a factor greater than two, but the method is limited to weak-phase objects and the desired image is accompanied by an unwanted background. It is now shown that these limitations of the method can be avoided if the technique is combined with an off-axis electron holography scheme.