Plot of the far-field diffracted intensity as a function of the angular position from the W/SiC MLL (a) (adapted from Ref. 16). A localized phase error at a scattering angle of approximately 10.3 mrad at 0.056 nm wavelength from the W/SiC lens gave rise to an obvious intensity spike16. At that position, the multilayer period was approximately 5.5 nm. Bright field (left column) and dark field (remaining columns) TEM images of W/SiC (b) and WC/SiC (c) have periods from 4.0 to 10 nm (as described in the Materials and Methods section). The white bar in all images corresponds to 20 nm. The transition from amorphous to crystalline W layers occurs at a period of approximately 5.7 nm.