Single-crystalline rutile TiO$_{2}$ nanowires by mass selected Ni catalyst: Synthesis and electrical properties

We present a novel method for growing high quality TiO$_{2}$ nanowires using mass-selected Ni clusters of nanometer sizes produced by magnetron sputtering and also show their electric field-effect functions. Single-crystalline TiO$_{2}$ nanowires(NWs) are grown by atmospheric pressure physical vapour deposition(APPVD) process, using TiO and Ti metal powders as a Ti source and Ni nanoparticles as a catalyst, respectively. For the TiO$_{2}$ NWs growth, first, the Ti metal layer with a thickness of $\sim $50nm was then deposited on the SiO$_{2}$/Si substrate by the e-beam evaporation technique and subsequently, the mass selected Ni clusters by using magnetron sputtering source combined with a quadrupole mass filter was deposited onto the Ti layer. APPVD growth was then performed in a horizontal quartz tube furnace at 800$^{\circ}$C-950$^{\circ}$C by introducing high purity Ar carrier gas (99.999{\%}) with the flow rate of 300 sccm for 2 hours. The $I-V$ curves are linear over the entire annealing temperature range at 200 $\sim$500$^{\circ}$C, showing that the electrodes form good ohmic contacts with the nanowires. The $I $vs $V_{G}$ curves for various values of $V_{SD}$ and gate dependent $I-V $curves of a TiO$_{2}$ nanowire configured as a back-gated FET are also obtained and will be discussed.