Pressure and Temperature Dependence of Field-Induced Oscillation in Two-Terminal Device Based on Vanadium Dioxide Thin Film.

In this paper, we investigated the pressure and temperature dependence of the frequency and amplitude of the field-induced oscillation created in a two-terminal device based on a vanadium dioxide (VO₂) thin film. First, a simple oscillation circuit was constructed using a VO₂-based two-terminal device, a standard resistor, and a DC power supply. Then, the frequency and amplitude variation of the field-induced oscillation was observed for pressure changes applied to the VO₂ device in a pressure chamber. This variation of the oscillation characteristics was also examined for ambient temperature changes applied to the VO₂ device using a plate heater. When the chamber pressure increased from 0 to 5 MPa with a step of 1 MPa at 25 °C, the oscillation frequency increased from ~592 to ~739 kHz, and the oscillation amplitude decreased from ~12.60 to ~11.40 V. Similarly, when the heater temperature increased from 25 to 50 °C (step: 5 °C) without applied pressure, the oscillation frequency increased from ~592 to ~819 kHz, and the oscillation amplitude decreased from ~12.60 to ~7.16 V. Owing to linear pressure and temperature responses of the VO₂ oscillation, the pressure and temperature sensitivities of the oscillation frequency and amplitude could be obtained as four different constant coefficients from the measurement results. These coefficients can be directly utilized for simultaneously measuring pressure and temperature variation applied to the VO₂ device, which can be beneficially applied to localized temperature and pressure sensing at a very small area less than 1 mm².