Magnetic liquids

Four types of liquid media — diamagnetic, non-magnetic, paramagnetic and ferrimagnetic — are described, and expressions for the dependence of the magnetic susceptibility on the modal concentration of the paramagnetic component are derived for the first three. Measurement results at room temperature for aqueous solutions of rare-earth- and Mn salts (nitrates and chlorides) are discussed. The magnetic susceptibility of rare earth nitrate solutions in some organic solvents at room temperature and at about 200 K is also considered. An example of ferrimagnetic suspension in water and in organic liquids is presented. Data on the viscosity of the rare earth- and the Mn solutions (nitrate and chlorides) as functions of molality are compared. Separation of a five-component mineral mixture in an aqueous solution of erbium nitrate is analysed.