Nanoscale Correlations between Metal–Insulator Transition and Resistive Switching Effect in Metallic Perovskite Oxides

Abstract

Strongly correlated perovskite oxides are a class of materials with fascinating intrinsic physical functionalities due to the interplay of charge, spin, orbital ordering, and lattice degrees of freedom. Among the exotic phenomena arising from such an interplay, metal–insulator transitions (MITs) are fundamentally still not fully understood and are of large interest for novel nanoelectronics applications, such as resistive switching‐based memories and neuromorphic computing devices. In particular, rare‐earth nickelates and lanthanum strontium manganites are archetypical examples of bandwidth‐controlled and band‐filling‐controlled MIT, respectively, which are used in this work as a playground to correlate the switching characteristics of the oxides and their MIT properties by means of local probe techniques in a systematic manner. These findings suggest that an electric‐field‐induced MIT can be triggered in these strongly correlated systems upon generation of oxygen vacancies and establish that lower operational voltages and larger resistance ratios are obtained in those films where the MIT lies closer to room temperature. This work demonstrates the potential of using MITs in the next generation of nanoelectronics devices.

Transverse barrier formation by electrical triggering of a metal-to-insulator transition

“…Our resistor network simulations show that the insulating barrier that forms during the M → I volatile switching concentrates not only the dissipated power but also the applied voltage. It is possible that the transverse barrier formation can occur in systems which feature a nonvolatile low-to-high-resistance switching caused by ion electromigration, such as rare-earth nickelates 77,78 , manganites [77][78][79][80][81][82] , and cuprates 77,79,83 . In fact, spatial patterns previously reported for the nonvolatile switching in YBa 2 Cu 3 O 7 83 , LSMO 84 and in NdNiO 3 85 can be rationalized by considering the tendency of low-to high-resistance switching to occur by the formation of a transverse insulating barrier.…”

Low-temperature emergent neuromorphic networks with correlated oxide devices

“…In general, there are many other strongly correlated materials that display resistive properties highly sensitive to the valency of the d -metal ion ( 10 ). For instance, vanadium oxides have recently emerged as key materials for designing neuron-like resistors ( 52 ).…”

“…These macroscopic collective responses emerge from microscopic quantum mechanical interactions. As a result, brain-inspired computing paradigms—known broadly as neuromorphic ( 4 , 5 )—based on these quantum materials are prominent in the goals of various research efforts to explore and hopefully spawn the next technological revolution ( 6 – 10 ).…”

Structural characterization and magnetic properties of single‐crystalline (La0.6Pr0.4)0.67Ca0.33MnO3 nanowires

“…Rare earth‐doped perovskite manganite oxides have promising applications in modern microelectronic devices due to their interesting electronic and magnetic properties, such as colossal magnetoresistivity (CMR), 1,2 metal–insulator transition (MIT), 3,4 nanoscale charge and orbital ordering, 5‐7 and electronic phase separation (EPS), 8‐10 because of strong couplings among the spin, orbit, charge, and lattice degrees of freedom. As a prototypical system of doped perovskite manganite oxides, the Ca‐doped LaMnO 3 (La 1‐x Ca x MnO 3 ) system shows an optimal MIT at x = 0.33, and the La 0.67 Ca 0.33 MnO 3 (LCMO) compound exhibits a considerable CMR effect and large magnetocaloric effect (MCE); this makes LCMO a promising candidate for the development of advanced magnetic sensors and refrigerators 11,12 .…”