Supression of the metal-to-insulator transition and jamming transition revealed in metal-oxides by nano-focused and coherent x-rays

Abstract
Metal-oxides with a structural transition coupled to the metal-to-insulator transition (MIT) have inherent built-in memory, reminiscent of synapses and neurons, making them natural candidates for neuromorphic computing. In devices, electrical switching leads to the stochastic formation of a conductive filament. Here, X-ray nano-diffraction imaging reveals regions of high strain at phase boundaries with induced suppression of the transition. Additionally, X-ray photon correlation spectroscopy (XPCS) synchronized with electrical switching is utilized to study the dynamics associated with filament formation and to characterize cycle-to-cycle stability. The XPCS results show that there is a jamming transition upon electrical switching.