Improved thermooxidation and sedimentation stability of covalently-coated carbonyl iron particles with cholesteryl groups and their influence on magnetorheology

► Two-step covalent compact coating of CI particles. ► Smoother coated surface in comparison with bare one. ► Enhanced sedimentation stability and thermal stability in oxygen atmosphere. ► Favorable MR performance for suspensions containing 80 wt.% of coated CI particles.