We have prepared the FeCl4 and GaCl4 salts of a novel dihydrothienoquinonoide-extended BETS type donor, namely, BEDT-HBDST. These salts exhibit semiconducting temperature dependence down to 90K. The FeCl4 and GaCl4 salts are isomorphous with each other. The donor to anion ratio is 2:1. The donors stack in an A-B-B-A- manner along the a-axis. These salts are one-dimentional along the side-by-side direction since Fermi surface of these salts are opened along the stacking direction. Fe3+ ions of (BEDT-HBDST)2FeCl4 exist in a high-spin state of S=5/2 interacting antiferromagnetically with each other. But the antiferromagnetic interaction is weak. weak. |