Resistive asymmetry due to spatial confinement in first-order phase transitions

Abstract

We report an asymmetry in the R vs T characteristics across the first order metalinsulator transition (MIT) of V 2 O 3 nanowires. The resistance changes in a few, large jumps during cooling through the MIT, while it does it in a smoother way during warming. The asymmetry is greatly enhanced as the width of the nanowire approaches a characteristic domain size. Our results, together with previous reports in VO 2 [1] and FeRh [2] imply that asymmetry is a generic feature of first order phase transitions in 1D systems. We show that this behavior is a simple, elegant consequence of the combined effects of the transition hysteresis and the temperature dependence of the insulating gap in this case (and generically, the order parameter relevant for the physical observable). We conclude that our proposed asymmetry mechanism is universally applicable to many electronic first order phase transitions.

Non-thermal resistive switching in Mott insulator nanowires

“…1a, b). The nanowire widths (~100 nm) are comparable to the size of insulator/metal domains, as found in a previous study 38 , and further supported by resistor network simulations (Supplementary Note 1 and Fig. 1c-e) 1 .…”

Evidence for a coupled magnetic-crystallographic transition in La0.9Ce0.1Fe12B6

“…Similar sharp jumps and staircaselike transitions have been recently observed in other metamagnets such as FeRh-based systems [58][59][60][61]. Some authors attributed their origin to the AFM-FM phase boundary motion that is pinned by defects or inhibited by the stray field of the portions that have already converted [58]; others proposed the combined effects of the transition hysteresis and the temperature dependence of the order parameter [59]. Instead, Uhlíř et al [61] suggested an alternative mechanism driven by the stronger exchange correlations of the long-range FM order compared to the AFM state, i.e., the robustness of the FM exchange to local strain and disorder when compared with the AFM exchange.…”

“…Similar sharp jumps and staircaselike transitions have been recently observed in other metamagnets such as FeRh-based systems [58][59][60][61]. Some authors attributed their origin to the AFM-FM phase boundary motion that is pinned by defects or inhibited by the stray field of the portions that have already converted [58]; others proposed the combined effects of the transition hysteresis and the temperature dependence of the order parameter [59].…”

Operando characterization of conductive filaments during resistive switching in Mott VO 2

“…Moreover, this IMT shows a resistive asymmetry between the heating and cooling branches. The broadening of the hysteresis and the asymmetry in the R-T curve have been observed in many one-dimensional correlated oxide systems (21,22). In addition, like other transition-metal oxides (1,18,23), oxygen migration in VO 2 may lead to the formation of oxygen-deficient filaments.…”