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We investigated the effect of a ferroelectric Pb(Zr0.52Ti0.48)O3 (PZT) thin film on the generation of resistive switching in a stacked Pr0.7Ca0.3MnO3 (PCMO)/Nb-doped SrTiO3 (Nb:STO) heterostructure forming a p-n junction. To promote the ferroelectric effect, the thin PZT active layer was deposited on an epitaxially grown p-type PCMO film on a lattice-matched n-type Nb:STO single crystal. It was concluded that the observed resistive switching behavior in the all-perovskite Pt/PZT/PCMO/Nb:STO heterostructure was related to the modulation of PCMO/Nb:STO p-n junction’s depletion width, which was caused either by the PZT ferroelectric polarization field effect, the electrochemical drift of oxygen ions under an electric field, or both simultaneously.

Memory performances, especially uniformity and reliability of resistance random access memory (RRAM) devices with W/NbO x /Pt structures were investigated. Scaling down the active device area (ø ¼ 250 nm) can significantly minimize extrinsic defects related to nonuniform switching and also demonstrate low-voltage SET/RESET operations due to increased Joule heating. Electromigration of oxygen ions under the bipolar electric field, bilayer formation, and lightning-rod effect localized at WO x /NbO x interface can explain the improved switching behavior in this novel stack. Excellent device characteristics such as lower switching voltage, fast switching speed (100 ns), high-temperature retention (>10 4 s, 85 8C), stable cycling endurance (10 7 cycles), almost 100% device yield and excellent switching uniformity are obtained.

Glassy carbon is frequently used in electrochemical research due to its presumed robust electrochemical performance. Although it is widely utilized as a rotating disc electrode material, the modification of glassy carbon during electro‐catalytic process is rarely emphasized or characterized. In this report, we investigated the structural modification of glassy carbon imparted by electrochemical oxidation in acidic media and compared the behavior with graphite. The functional groups generated from electrochemical oxidation in both electrodes possess similar electrochemical properties. However, above an oxidation potential of 1.8 V (vs. reversibly hydrogen electrode), glassy carbon exhibits a lower electrochemical capacitance compared to graphite. We propose that the existence of electrochemically inactive species, originating from the non‐graphitic portion of glassy carbon is attributed to such deterioration. Additionally, high resolution scanning electron microscopy (HR‐SEM) and high‐resolution transmission electron microscopy (HR‐TEM) images corroborate how electrochemical oxidation prevails for glassy carbon electrodes at oxidative potentials. The overall analysis leads us to propose a corrosion mechanism for glassy carbon in acidic solution.

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