Magnetic Behavior of Ternary Insulating Co/Mn/Fe Dichloride Dihydrate

The possible binary mixed magnets based on the isomorphous components cobalt, manganese and iron dichloride dihydrate have been well studied. Quite different looking T vs composition phase diagrams occur for the three binary mixtures and can be at least partly understood on the basis of competing orthogonal spin anisotropies (Co/Fe mixture), competing ferromagnetic and antiferromagnetic exchange interactions (Co/Mn mixture), and both types of competition (Mn/Fe mixture). Four different ternary compositions were prepared and studied previously in order to begin to map out the composition dependent magnetic properties in one of the very few practicable ternary insulating magnets, and the first examined [G.C. DeFotis et al., J. Appl. Phys. 87, 6540 (2000)]. An even larger number of new compositions have been prepared and studied for this report. Composition dependences are examined regarding high temperature paramagnetic behavior, occurrence of magnetic transitions, and the presence of magnetic irreversibility. *Supported by NSF-Solid State Chemistry-Grant No. DMR-0085662 and by the Petroleum Research Fund of the American Chemical Society.