Anodic oxidation of vanadium and properties of vanadium oxide films

Abstract

Thin films of amorphous vanadium oxide have been prepared by electrochemical anodic oxidation. The phase composition of anodic films on vanadium has been shown to depend on the oxidation conditions (electrolyte composition, oxidation current, and time), and the stoichiometry can be controlled from VO 2 to V 2 O 5 . Physical properties of the oxide films, including the metal-insulator transition in amorphous VO 2 , are studied. In addition, it is shown that non-equilibrium electrochemical oxidation leads to the formation of metastable vanadium oxides with extremely high sensitivity to laser (∼1 mJ cm −2 ) and electron-beam (∼10 µC cm −2 ) irradiation. Such films are of considerable technical interest, particularly because of potential applications as an efficient resist material for both photonanolithography and electron-beam nanolithography.

Oxide Electronics and Vanadium Dioxide Perspective: A Review

“…Experiments on the initiation of the MIT using photogeneration of charge carriers by femtosecond laser pulses [63], [64] without lattice heating to T = T t indicate that the electron-electron interaction is also of importance for a correct description of the transition. This is supported by studies of the MIT in thin films of amorphous vanadium dioxide [62] obtained by anodic oxidation [45], [65].…”

“…It has been shown [62], [65] that the XRD spectrum of the anodic vanadium oxide exhibits diffuse maxima typical for amorphous materials. The occurrence of the MIT in these structurally disordered VO 2 films has been indicated by an abrupt and considerable (although reversible) change in the conductivity at T = 310-330 K, and this temperature practically coincides with the transition temperature for the MIT in crystalline VO 2 , T t = 340 K. The importance of these results consists in the evidence that the metal-insulator phase transition in VO 2 is preserved in the absence of a long-range crystallographic order.…”

Fabrication and Characterization of Highly-Ordered Valve-Metal Oxide Nanotubes and Their Derivative Nanostructures

“…It should be pointed out that porous anodic oxide films have also been made on the surfaces of other metals, such as hafnium, 200 niobium, 201 tantalum, 202 tungsten, 203 vanadium, 204 and alloys of Ti-Mo, 205 Ti-W, 206 Ti-Nb, 207 Ti-V, 208 Ti-Zr, 209 Ti-Ta, 210 and Ti-Al. 211 In the literature, most of the research concentrated on Al and Ti, while less research was completed on other systems including Zr.…”

Thermochromic Properties of VO2-PVP Composite Coatings

“…Due to the small compositional differences between the numerous phases of vanadium oxide, hence VO 2 preparation requires a stringently controlled process that provides the desired oxygen stoichiometry and correct crystalline structure. VO 2 films have been successfully synthesized by a number of methods (physical and chemical), including DC and RF reactive magnetron sputtering [42][43][44][45][46][47], reactive ion-beam sputtering [48][49][50][51][52], reactive evaporation [53,54], chemical vapor deposition [55][56][57], pulsed laser deposition (PLD) [58][59][60][61][62], electrochemical (anodic) oxidation [63,64] and sol-gel processes [65][66][67]. Given the requirement for accurate optimization to obtain the correct VO 2 polycrystalline structure, and due to the numerous electronic valences of vanadium and its high affinity for oxygen, it is challenging to produce large thermochromic VO 2 thin dddfilms using such techniques.…”