Highly Thermally Resilient Dual‐Mode (Digital/Analog) Amorphous Yttrium Fluoride Memristors Exhibiting Excellent Symmetric Linearity

AbstractThis paper describes the first use of vacuum‐deposited YF3 films as active materials in memristors. These YF3 memristors function with extraordinary dual digital/analog operation modes. In both modes, the memorization states are all non‐volatile, with long retention times (up to 106 s). In the analog mode, the memristors achieve a stable series of consecutive cycles of 64‐level potentiation and depression, with large ON/OFF resistance ratios (up to 7.2), and extraordinarily balanced linearity. With these YF3 memristors, an excellent recognition accuracy of 97% in the classification of handwritten digits is achieved. Time‐of‐flight secondary ion mass spectroscopy, X‐ray photoelectron spectroscopy, and valance change memory modeling to examine the switching mechanism of YF3 are used, discovering that fluorine vacancy species are responsible for the memristor behavior. Excellent high‐temperature stability during both operation and state preservation suggests that these YF3 memristors might find applicability in neuromorphic computing under relatively harsh conditions.