ESR-Experiments on the Radical Cation Salt (Naphthalene) 2 AsF -6

ESR- and DC-conductivity measurements on (Naphthalene)2 AsF6 show in metallic properties above 240 K with the narrowest ESR-line (ΔBpp = 2,5 mG) found so far in solids. Below 240 K we have a semiconductor and at about 110 K a structural phase transition which leads to an enhancement of the ESR-linewidth by one order of magnitude.