Thermal filaments in vanadium dioxide

A relatively simple thin-film structure using vanadium dioxide is analyzed in detail to show that high-temperature, low-resistivity filaments can exist in VO2under appropriate electrical bias. These filaments will dominate both the static and dynamic electrical behavior of the structure, giving rise to V-I characteristics similar to those expected from materials exhibiting current-controlled bulk negative resistivities. The analysis indicates that these filaments may not only provide electrical features important from a device point of view, but also provide a tool for the measurement of fundamental material properties and for studying the dynamics of the phase transition in VO2.