  The infrared optical, magneto-optical and magnetostrictive properties of
CoFe2O4 single crystal are considered. The magneto-transmission and
magneto-reflection of natural light in magnetostrictive CoFe2O4 spinel are
studied in the Voight experimental geometry. These magneto-optical effects are
very high and associate with a change of the fundamental absorption edge and
impurity absorption bands under magnetic field. It is presented the effects
strongly depend on both the magnitude and orientation of magnetic field
relative to the crystallographic axes of the crystal. The clear connection
between magneto-absorption of light in the infrared spectral range and
magnetostriction of CoFe2O4 spinel is established. The contribution of
magnetostriction to the magnetic anisotropy constant of the CoFe2O4 crystal is
shown to be abnormally great.
