Enhanced Sm spin projection in GdxSm1-xN

The rare-earth nitrides form a series of structurally simple intrinsic ferromagnetic semiconductors, a rare class of both fundamental interest and application potential. Within the series there is a wide range of magnetic properties relating to the spin/orbit contributions to the ferromagnetic ground states. We report an x-ray magnetic circular dichroism investigation of the spin/orbit magnetic dipole alignments of Sm and Gd ions in epitaxial GdxSm1-xN films. The Sm spin-alignment expectation value (Sz) is seen to be strengthened by the Gd/Sm exchange interaction, providing guidance that the composition for an angular momentum compensation point, where the volume-averaged total angular momentum of a film is zero, lies near x = 0.24.