Enhanced resistive switching performance of spinel MnCo2O4 resistive random access memory devices: Effects of annealing temperatures and annealing atmospheres

The spinel MnCo2O4 (MCO) thin films were fabricated on Pt/Ti/SiO2/Si substrates for resistive memories via sol -gel spin-coating deposition method under different annealing temperatures and annealing atmospheres. The 650oC-annealing Pt/MCO/Pt device shows better bipolar resistance switching parameters than the devices annealed at 600 degrees C and 700 degrees C. The nitrogen-annealing Pt/MCO/Pt device exhibits optimum resistance switching parameters due to increasing of the oxygen-vacancies proportion, formation of confined and stable conductive filaments, and suppressing of the randomness of oxygen vacancies. The carrier transportation mechanisms of the devices with numerous oxygen-vacancies content in low resistance state (LRS) and high resistance state (HRS) are dominated by Ohmic conduction and Schottky emission, respectively. For the devices with fewer oxygen-vacancies content, the conduction mechanisms at LRS and HRS can be described by nearest-neighboring hop-ping conduction and space-charge-limited current model, respectively. This work indicates that the spinel MCO films have good potential application in resistive random access memory.