Density functional theory study on conduction mechanisms in LaFeO3 nanofibers for resistive random access memory

Resistive random access memory (RRAM) is widely recognized as a highly promising competitor for next-generation mainstream memory solutions. Rare earth perovskite oxides can meet the requirements of RRAM for high reliability of storage media, adjustable resistive switching, low power consumption, and high compatibility with CMOS processes. This study systematically explored the conduction mechanism of electrospun LaFeO 3 nanofibers by regulating electrode materials to enhance their potential application in the next-generation RRAM devices. The surface of LaFeO 3 nanofibers was relatively smooth and the diameter was approximately 460 nm. The XPS results revealed the existence of La 3+ , Fe 2+ /Fe 3+ and oxygen vacancies in LaFeO 3 . The conduction mechanism of LaFeO 3 as a switching medium in RRAM devices were analyzed by density functional theory (DFT). The results showed that LaFeO 3 exhibited favorable electrical conductivity due to the strong hybridization of Fe 3d-O 2p orbitals, and oxygen vacancies played a key role in the formation of conductive filaments. Among Ag/LaFeO 3 /Ag, Ag/LaFeO 3 /Pt and Pt/LaFeO 3 /Pt devices, the Ag/LaFeO 3 /Pt device possessed the best performance due to electrode optimization. The energy barrier of the Ag/LaFeO 3 /Pt device was relatively low which enabled the favorable resistive switching performance with both a moderate operating voltage and a relatively high on/off ratio. These findings indicated that the low energy barrier and efficient resistive switching characteristics of LaFeO 3 nanofibers induced by oxygen vacancies/Ag ions provided an important theoretical support for the development of low power and high-performance RRAM devices.