Single‐crystalline Mn‐, Ni‐, and Al‐substituted copper ferrite films are grown by the LPE method from a PbO‐B2O3flux on (111)‐MgO substrates. Solid solutions between copper ferrite and Mn3O4, NiFe2O4, and CuAl2O4are obtained. The segregation coefficients for Ni and Al are shown to be linearly dependent on the growth temperature. From domain‐structure observations and from torque measurements it is concluded that a positive uniaxial anisotropy is present in the copper ferrite films. After stress relief at the deposition temperature a stress develops during cooling to room temperature due to a difference in thermal expansion coefficients of film and substrate. This stress is responsible for the observed anisotropy.