Weak ferromagnetism in a semiconducting (ethylenedithiodiselenadithiafulvalenoquinone-1,3-diselenolemethide)2•FeBr4 salt

The 2:1 salts of a new bent donor molecule, ethylenedithiodiselenad ithiafulvalenocluinone- 1, 3-diselenolemethide (EDT-DSDT-FVODS) and either an FeBr4-, or a GaBr4- ion exhibit semiconducting properties and had small activation energies. The Fe-III d spins of the FeBr4- salt are initially subject to a strong antiferromagnetic interaction and afterward exhibited a weak ferromagnetism at 3.8 K With a very small remanent magnetization of ca. 4 x 10(-2) mu(B) and a spin-flop near 25 kOe along the intercolumnar direction.