Synaptic Learning and Memory Functions Achieved in Self-rectifying BFO Memristor under Extreme Environmental Temperature

TL;DR

This study demonstrates that BiFeO3 memristors maintain ferroelectricity and synaptic functions across a wide temperature range, including extreme temperatures up to 500°C, making them promising for robust neuromorphic applications.

Contribution

The paper reports the first demonstration of ferroelectricity and synaptic functions in BFO memristors at temperatures up to 500°C, highlighting their environmental robustness.

Findings

Ferroelectricity of BFO films persists at 500°C.

Analog-like resistance switching observed across -170°C to 300°C.

Synaptic functions like LTP, LTD, and STDP are achieved at high temperatures.

Abstract

Memristors have been intensively studied in recent years as promising building blocks for next-generation non-volatile memory, artificial neural networks and brain-inspired computing systems. Even though the environment adaptability of memristor has been required in many application fields, it has been rarely reported due to the underlying mechanism could become invalid especially at an elevated temperature. Here, we focus on achieving synaptic learning and memory functions in BiFeO3 memristor in a wide range of temperature. We have proved the ferroelectricity of BFO films at a record-high temperature of 500 {\deg}C by piezoresponse force microscopy (PFM) measurement. Due to the robust ferroelectricity of BFO thin film, an analog-like resistance switching behavior has been clearly found in a wide range of temperature, which is attributed to the reversal of ferroelectric polarization. Various synaptic functions including long-term potentiation (LTP), depression (LTD), consecutive potentiation/depression (P/D) and spike-timing dependent plasticity (STDP) have been realized from -170 to 300 {\deg}C, illustrating their potential for electronic applications even under extreme environmental temperature.