Sharp Phase Transition by the Enhanced Lattice Stability of Low‐Temperature Phase of Cr‐Doped VO 2

We have prepared Cr‐doped VO 2 film (V 1− x Cr x O 2 , 0 ≤  x  ≤ 0.15) on a c ‐cut sapphire plate (0001). The insulator to metal transition (IMT) behavior of the VO 2 was observed by the resistance and transmittance measurements near the phase transition point ( T c  ~ 340 K). Whereas the starting point of metal to insulator transition ( T HE ) was nearly constant at 350 K ( x  ≤ 0.03), the starting point of the insulator to metal transition ( T HS ) was shifted from 308 K ( x  = 0) to 326 K ( x  = 0.05), suggesting that the Cr‐doped VO 2 lattice is significantly stabilized below T c of the VO 2 . The difference between T HS and T HE and the gap between thermal cycles (hysteresis gap), which reflect the sharpness of the phase transition, were minimal at x  = 0.03–0.05 in V 1− x Cr x O 2 . This sudden phase transition of Cr‐doped VO 2 is expected to be uniquely advantageous for sensitive on–off applications.