Fig. 1: Resistance change behavior upon phase change in MnTe.

a Temperature dependence of resistance of the as-deposited MnTe film during heating followed by cooling to RT; the step decrease in resistance at around 200 °C is due to the experimental error caused when the measuring range is switched from 10⁶ to 10⁵. The inset shows X-ray diffraction (XRD) patterns at room temperature (RT) of as-deposited (blue) and 500 °C annealed (red) films. b A resistance (R) vs. voltage (V) curve for MnTe (open circles) and Ge₂Sb₂Te₅ (GST225) devices (filled circles), read voltage was 0.1 V. The as-annealed MnTe device with low resistance was used for the measurement; the GST225 device was first annealed at 260 °C then cooled to RT and finally it was RESET-operated by applying 13.8 V for 50 ns before the measurement. Solid arrows indicate the critical voltage for RESET (V_RESET) and SET (V_SET) operations, and dashed arrows indicate the resistance of RESET (R_RESET) and SET (R_SET) states; these parameters were used for the operation energy calculation.