Modeling Local Distortions in Zn_1-xMg_xO Ferroelectrics

Non-von Neumann computing architectures offer opportunities to maximize the energy efficiency and floating-point-computation performance of microprocessors, beyond the von Neumann computing model in which the data-storage and data-processing functions of the computer are physically separated. One example of such architectures is three-dimensional ferroelectric microelectronics (3DFeMs) that take advantage of third-dimensional interconnects, enabling low-power computation. The integration of ferroelectric memory capabilities into field-effect transistors requires the development of ferroelectric materials that would be scalable and compatible with current microelectronic technologies. In this work, we study the mechanisms of polarization switching in recently proposed Zn_1−xMg_xO (ZMO) ferroelectric materials. To understand cation ordering in ZMO at finite temperature, we validated and applied large-scale Monte Carlo simulations in the canonical ensemble using Metropolis and Wang-Landau samplings. Finite-temperature Monte Carlo simulations strongly suggest that short-range cation ordering critically influence the stability and ferroelectric response of ZMO compounds. Analyzing local distortions associated with temperature-dependent cation ordering may ultimately provide insight into the mechanisms facilitating polarization switching in ZMO.