Selectable Titanium-Oxide-Based Critical and Differential Temperature Sensor in a Single Devices

We propose a titanium oxide (TiO
_x
)-based temperature sensor that can be operated in two ways, namely, by showing either abrupt or gradual metal-insulator transition (MIT) characteristics. For an as-prepared reliable TiOx-based MIT device, both abrupt and gradual MIT characteristics were observed under varying bias and temperature conditions. These results strongly demonstrate that two different types of temperature sensor (critical temperature sensor and differential temperature sensor) can be selectively operated by varying the applied bias in a single MIT device.