Layer-by-Layer Resistive Switching: Multistate Functionality due to Electric-Field-Induced Healing of Dead Layers

Abstract

Materials exhibiting reversible resistive switching in electrical fields are highly demanded for functional elements in oxide electronics. In particular, multilevel switching effects allow for advanced applications like neuromorphic circuits. Here we report on a structurally driven switching mechanism involving the so-called "dead" layers of perovskite manganite surfaces. Forming a tunnel barrier whose thickness can be changed in monolayer steps by electrical fields, the switching effect exhibits well-defined and robust resistive states.

Polaronic Emergent Phases in Manganite-based Heterostructures

“…From the fitting of the current-thickness dependence in Figure 10e by the Simmons model [35] reasonable values for the minimum barrier thickness z 0 ≈ 1.3 nm and the electrical contact area A ≈ 2.0 nm 2 were obtained. The evaluated barrier height φ = 46 meV has to be considered as a rough estimate, but in any case, φ cannot exceed 60 meV.…”

“…Electric-field-driven resistive switching, being widely spread phenomenon in heterostructures of correlated oxides, including perovskite manganites, [89][90][91] was believed to be promising for novel multistate resistive memory (memristive) applications including advanced neuromorphic computing [73,92,93]. Recently [35] we have demonstrated that a multistate functionality can be obtained in an intrinsic heterostructure, comprising the "dead layer" (DL) at the surface of a manganite film. The DL acting as a tunneling barrier plays a most active role being electrically switchable in monolayer steps between two intrinsically well-defined resistance states.…”

“…According to our model [35], a dead layer at the surface, in contrast to the metallic LSMO in bulk, is viewed as a Mott-Hubbard insulator with a gap opening due to electronic correlations. Because of this gap, an intrinsic tunnel barrier is formed between the bottom (bulk metallic-like LSMO) and the top (Pt-coated AFM tip) electrodes.…”

“…By applying SERS, we observed such phases at the surface of a manganite [32] because of the symmetry-break-induced electronic reconstruction, theoretically predicted by Calderon et al [33]. The importance and novelty of artificial nanoscale EPs is highlighted by the observations of (1) a high-T C ferromagnetic EP at the SrMnO 3 (top)/LaMnO 3 (bottom) (SMO/LMO) interface [34] caused by the electron transfer from the LMO "donor" layer into the SMO "acceptor" layer, and (2) the electric-field-induced resistance switching in the layer-by-layer fashion [35] of electrically highly isolated "dead layer" at the La 0.7 Sr 0.3 MnO 3 (LSMO) surface and formation of the embedded conducting layers, which allow a robust multi-state memristive functionality.…”

Extraction of Switching Parameters for Sr‐Doped YMnO3 Thin Film

“…Various materials have shown the RS effect, but transition metal oxides have attracted considerable attention because of their potential applications in nonvolatile memory . The RS phenomenon was observed in binary oxides such as Fe 2 O 3 , NiO, and ZnO and perovskite‐based oxides such as SrTiO 3 and manganites . Among various manganite materials, RS has been studied considerably in yttrium‐based manganites .…”