Electrical triggering of metal-insulator transition in nanoscale vanadium oxide junctions

Abstract

200 nm diameter Au contacts were fabricated by e-beam lithography on sputtered thin film vanadium oxide grown on conducting substrates and current perpendicular to plane electron transport measurements were performed with a conducting tip atomic force microscope. Sharp jumps in electric current were observed in the I-V characteristics of the nano-VO2 junctions and were attributed to the manifestation of the metal-insulator transition. The critical field and dielectric constant were estimated from quantitative analysis of the current-voltage relationship and compared with reported values on micrometer and larger size scale devices. These results are of potential relevance to novel oxide electronics utilizing metal-insulator transitions.

Effect of W addition on the electrical switching of VO2 thin films

“…8 for all compositions of doped VO 2 . Room temperature carrier density was found to be 3 x10 19 cm −3 which is similar to that reported by Ruzmetov et al 29 It was observed that with an increase in tungsten content, carrier concentration increased from 3x10 19 cm −3 for the undoped sample to 1.7x10 22 concentration. Tungsten with W 6+ valence when substituting for the V 4+ gives electrons per atom thereby increasing the number of charge carriers.…”

“…9 MIT in VO 2 can also be triggered by optical, 17 electrical, 18 mechanical means. [17][18][19] Characteristics of the transition is influenced by the nature of the phases (M1, M2, T, R), microstructure (i.e. morphology and relative orientation of the grains and the grain boundaries) 20 and doping.…”

Synthesis of vanadium dioxide thin films on conducting oxides and metal–insulator transition characteristics

“…The VO 2 film on Nb-doped SrTiO 3 shows over two orders of magnitude resistance change across the transition. The VO 2 film on RuO 2 buffered TiO 2 shows a two step transition.…”

“…To date, VO 2 films have primarily been grown on conducting substrates such as heavily-doped Si or Ge, and Pt [3][4][5]. As far as conducting oxide substrates are concerned; there is a recent report discussing the role of twin boundaries of VO 2 grown on Ga-doped ZnO buffered c-sapphire [6].…”

“…VO 2 films grown on conducting oxides would be of particular interest to explore all-oxide electronics wherein the underlayer could be used as an electrode for electron transport. Therefore, here we have studied the physical properties of VO 2 grown on conducting oxide substrates namely Nb-doped SrTiO 3 single crystal substrate and RuO 2 buffered TiO 2 single crystal substrate. grown by pulsed chemical vapor deposition in a home-built tube reactor [7], with bis(N,N'-di-tertbutylacetamidinato) ruthenium (II) dicarbonyl as the ruthenium precursor and oxygen as co-reactant gas.…”