Development of suspensions of rod-shaped β–FeOOH particles in infrared transmitting solvents for use as artificial Kerr media

Abstract

The first suspensions of rod-shaped dielectric particles in an infrared transmitting solvent are reported. Specifically, micron size β–FeOOH rods have been produced in chloroform, carbon tetrachloride, and carbon disulfide. A technique to transfer the particles from water into organic solvents is demonstrated and a novel optical method to determine the degree of stability of the organosols is used. Sedimentation times vary with preparation technique over the range of minutes to hours, often being long enough to allow the use of the material as an infrared Kerr medium with large electric field induced birefringence. Dispersions in hexane, which has good microwave transmission, have also been produced.