“…Among various NVMs, the RRAM composed of a simple metal-insulator-metal (M-I-M) structure has the merits of low power consumption, high speed operation and high density integration. Due to these excellent characteristics, a number of metal oxides such as SrZrO 3 [1,2], Pr 1-x Ca x MnO 3 [3], ZrO 2 [4], TiO 2 [5,6], Cu x O [7,8], and NiO [9][10][11][12][13][14], have been extensively studied for possible NVM applications.…”