We present results from an experimental study of the equilibrium and non-equilibrium transport properties of vanadium oxide nanobeams near the metal-insulator transition (MIT). Application of a large electric field in the insulating phase across the
nanobeams produces an abrupt MIT and the individual roles of thermal and non-thermal effects in driving the transition are studied. Transport measurements at temperatures ($T$) far below the critical temperature ($T_c$) of MIT, in several nanoscale vanadium oxide devices, show that both $T$ and electric field play distinctly separate, but critical roles in inducing the MIT. Specifically, at $T << T_c$ electric field dominates the MIT through an avalanche-type process, whereas thermal effects become progressively critical as $T$ approaches $T_c$.
NbSe3 exhibits remarkable anisotropy in most of its physical properties and has been a model system for studies of quasi-one-dimensional charge-density-wave (CDW) phenomena. Herein, we report the synthesis, characterization, and electrical transport
of single-crystalline NbSe3 nanoribbons by a facile one-step vapour transport process involving the transport of selenium powder onto a niobium foil substrate. Our investigations aid the understanding of the CDW nature of NbSe3 and the growth process of the material. They also indicate that NbSe3 nanoribbons have enhanced CDW properties compared to those of the bulk phase due to size confinement effects, thus expanding the search for new mesoscopic phenomena at the nanoscale level. Single nanoribbon measurements on the electrical resistance as a function of temperature show charge-density wave transitions at 59 K and 141 K. We also demonstrate significant enhancement in the depinning effect and sliding regimes mainly attributed to finite size effects.
