We report the Ni ${\mathrm{L}}_{2,3}$-edge magnetic circular dichroism (MCD) measurements of ferrimagnetic ${\mathrm{Zn}}_{\mathrm{x}}$${\mathrm{Ni}}_{1\mathrm{-}\mathrm{x}}$${\mathrm{Fe}}_2$${\mathrm{O}}_4$ (x=0.0, 0.26, 0.50, and 0.75). The Ni MCD asymmetry ratio was found to decrease with increasing x, showing a reduction of the Ni average magnetic moment with Zn content. This observation is interpreted in terms of the variations in the Yafet-Kittel-type canted angles of the Ni moment, giving new insight into the superexchange interactions involving the Ni ions. A comparison with the non-Ni-specific neutron scattering and Mössbauer studies is given.

DOI:https://doi.org/10.1103/PhysRevB.55.11409