  We have engineered an antiferromagnetic domain wall by utilizing a magnetic
frustration effect of a thin iron cap layer deposited on a chromium film.
Through lithography and wet etching we selectively remove areas of the Fe cap
layer to form a patterned ferromagnetic mask over the Cr film. Removing the Fe
locally removes magnetic frustration in user-defined regions of the Cr film. We
present x-ray microdiffraction microscopy results confirming the formation of a
90{\deg} spin-density wave propagation domain wall in Cr. This domain wall
nucleates at the boundary defined by our Fe mask.
