Spin density wave and superconducting properties of nanoparticle organic conductor assemblies

The magnetic susceptibilities of nanoparticle assemblies of two Bechgaard salts ${(\mathrm{TMTSF})}_{2}{\text{PF}}_{6}$ and ${(\mathrm{TMTSF})}_{2}{\text{ClO}}_{4}$, have been studied vs temperature and magnetic field. In the bulk these materials exhibit a spin density wave formation $({T}_{\text{SDW}}\phantom{\rule{4pt}{0ex}}=12\phantom{\rule{4pt}{0ex}}\mathrm{K})$ and superconductivity $({T}_{\text{c}}=1.2\phantom{\rule{0.16em}{0ex}}\mathrm{K})$, respectively. We show from inductive (susceptibility) measurements that the nanoparticle assemblies exhibit ground-state phase transitions similar to those of randomly oriented polycrystalline samples of the parent materials. Resistivity and diamagnetic shielding measurements yield additional information on the functional nanoparticle structure in terms of stoichiometric and nonstoichiometric composition.