  Manipulating magnetic domains is essential for many technological
applications. Recent breakthroughs in Antiferromagnetic Spintronics brought up
novel concepts for electronic device development. Imaging antiferromagnetic
domains is of key importance to this field. Unfortunately, some of the basic
domain types, such as antiphase domains, cannot be imaged by conventional
techniques. Herein, we present a new domain projection imaging technique based
on the localization of domain boundaries by resonant magnetic diffraction of
coherent x rays. Contrast arises from reduction of the scattered intensity at
the domain boundaries due to destructive interference effects. We demonstrate
this approach by imaging antiphase domains in a collinear antiferromagnet
Fe2Mo3O8, and observe evidence of domain wall interaction with a structural
defect. This technique does not involve any numerical algorithms. It is fast,
sensitive, produces large-scale images in a single-exposure measurement, and is
applicable to a variety of magnetic domain types.
