K-ion intercalation memristors in prussian blue analogs revealed by C-AFM for Non-Volatile memory and Neuromorphic Computing

Abstract: Here, we demonstrate K-ion intercalation-mediated resistive switching in Prussian blue analogs (PBAs), a mechanism widely exploited in potassium batteries but not previously resolved at the nanoscale for memristive operation. Using C-AFM, we directly visualize and electrically control this intercalation process within sub-100-nm volumes, revealing reversible, localized conductance modulation driven by K-ion intercalation and Fe2+/Fe3+ redox reconfiguration. This nanoscale operability highlights the exceptional potential of PBAs for high-scalable and low-dimension memristor-based devices integration. Due to their modular composition, PBAs constitute a chemically rich, earth-abundant materials platform whose electronic and ionic properties can be precisely tuned for specific device functions. K-ion intercalation PBA-based memristor devices, with their singlestep, aqueous, and room-temperature fabrication, enable low-cost, large-scale processing compatible with CMOS, without any additional post-fabrication processing. Our findings establish PBAs as a new class of intercalation memristors with scalable nanoscale switching and exceptional materials versatility, toward highly integrated neuromorphic and non-volatile memory technologies. This work provides the first demonstration of intercalation-driven resistive switching under ultrafast voltage sweeps, with PW operating up to 200 V/s and PB up to 50 V/s. This unprecedented speed establishes PBAs as a distinct, high-rate class of K-ion intercalation memristors suitable for fast, high-density neuromorphic and memory applications.