engleski

Electrical conductivity in dynamically orientationally disordered systems: ac and dc measurements in ferromagnetic single crystals of TDAE-C-60

In spite of a metallic C/sub 60/ molecular ground state, electrical conductivity measurements performed on single crystals of ferromagnetic TDAE-C/sub 60/ fail to show evidence of metallic behavior. Instead, the material appears to be an insultor exhibiting conductivity of the form sigma ( omega , T)= sigma /sub DC/(T)+ sigma /sub AC/( omega ). Phonon-assisted activated polaronic hopping and interbuckyball tunneling, respectively, are proposed as the mechanisms for the two processes. The transition from a dynamically disordered state (rotating buckyballs) to a quasiordered state (frozen buckyballs) is clearly visible as a change in activation energy in the conductivity at T/sub 0/=150 K.

fullerene ; RbC60

nije evidentirano