The observation of spin-dependent photoelectron diffraction using circ
ularly polarized x rays is reported for Fe films on Cu(001). Circularl
y polarized x rays produce spin-polarized photoelectrons from the Fe 2
p doublet, and intensity asymmetries in the 2p3/2 level are observed.
Fully spin-specific multiple-scattering calculations reproduce the exp
erimentally determined energy and angular dependences. An analytical p
rocedure is introduced which removes exchange shift contributions to t
he Fe 2p asymmetry, and focuses instead upon intensity variations due
to spin-dependent diffraction.