Manipulating the electrical properties of conductive substoichiometric titanium oxides

Abstract

Conducting metal oxides offer many advantages for novel electronics applications, including sensors, fuel cells, piezoelectric devices, and microelectronic circuits, due to their conductivity, hardness, and chemically inert surfaces. In particular, their high electrical conductivity and mechanical properties make these materials suitable for microelectromechanical and nanoelectromechanical system (MEMS/NEMS) devices. NEMS switches have great potential for next-generation electronic computing associated with scalability to small dimensions, low power consumption, and (relatively) high speed. Oxygen-deficient Ti oxides with ordered planes of vacancies (TinO2n-1, Magnéli phases) are good candidates for NEMS applications because of their metallic conductivity, environmental resistance, and low cost, as compared with other conductive oxides like RuO2. Although Ti suboxides have been produced in crystalline form, various synthesis methods may also produce amorphous material. In this paper, we focus on the structural and electrical transport properties of several Ti suboxides. In particular, we examine the effects of temperature, transition-metal dopants, and amorphization on these structural and electronic properties and the potential applicability of Magnéli phase Ti suboxides for NEMS switch applications.