/PMN-PT heterostructures*

Oxide heterostructures provide an exciting opportunity to engineer new artificial systems with unique properties that cannot be found in naturally occurring materials. Enabling the control of electronic properties of oxides that feature a metal-insulator transition (MIT) is a key requirement for developing a new class of electronics often referred to as “Mottronics” [1]. Although doping and radiation damage are effective tools to permanently change the MIT temperature in these materials, a simple method to switch the MIT properties in real-time is needed for practical applications. In this talk I will present the discovery of giant nonvolatile resistive switching (ΔR/R > 1000%) and strong modulation of the MIT temperature (ΔT_c > 30 K) in a voltage-actuated V₂O₃/PMN-PT heterostructure. The control of the V₂O₃ electronic properties is achieved using the transfer of ferroelastic strain from the PMN-PT substrate into the epitaxially-grown V₂O₃ film. Strain can reversibly promote/hinder the structural phase transition in V₂O₃, thus advancing/suppressing the associated MIT. While oxide/ferroelectric hybrids had been studied in the past using other correlated materials, such as VO₂ [2], Fe₃O₄ [3], LaNiO₃ [4], NdNiO₃ [5], etc., the reported nonvolatile resistive switching was rather modest: 1.5% < ΔR/R < 110%. More than an order of magnitude larger resistive switching in V₂O₃/PMN-PT could enable practical implementations of voltage-controlled Mott devices and provide a new platform for exploring fundamental electronic properties of V₂O₃.

[1] Ngai, J. et. al. Annu. Rev. Mater. Res. 44, 1 (2014)
[2] Nan, T. et. al. Sci. Rep. 4, 5931 (2014)
[3] Liu, M. et. al. Sci. Rep. 3, 1876 (2013)
[4] Marshall, M. et. al. Phys. Rev. Appl. 2, 051001 (2014)
[5] Heo, S. et. al. Sci. Rep. 6, 22228 (2016)