Weak Ferromagnetism in a Semiconducting (Ethylenedithiodiselena- dithiafulvalenoquinone-1,3-diselenolemethide)₂·FeBr₄ Salt

The 2:1 salts of a new bent donor molecule, ethylenedithiodiselenadithiafulvalenoquinone-1,3-diselenolemethide (EDT-DSDTFVODS) 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 × 10^-2 μ_B and a spin-flop near 25 kOe along the intercolumnar direction.