Metal-insulator transition in individual nanowires of doped-V2O5

Recent studies on doped vanadium oxide bronzes ($M_{x}V_{2}O_{5}$) have shown remarkable transport and magnetic properties including charge and spin ordering, paramagnetism, gapless states and superconductivity. Here we present the results of transport measurements in single nanowires of $M_{x}V_{2}O_{5}$ ($M=K$, $Cu$, $Na$ or $W$). Individual nanowire devices are prepared by standard lithographic techniques and resistance ($R$) is measured as a function of temperature ($T$). $R$ vs. $T$ behavior of a typical nanowire shows multiple jumps in $R$ and hysteresis between 300 and 400 K, suggesting that metal-insulator transitions in individual nanowires may occur in several steps, changing parts of the wire from one phase to another as $T$ is varied. Metal-insulator transition in isolated nanowires is studied when the dopant composition, diameter or length is varied.