Resistive Memristor Coupled with Multilevel Perpendicular Magnetic States

Abstract

Memristor is an increasingly important research field for inmemory computing (IMC) due to its significant potential in neuromorphic computing. A resistive memristor that can integrate components with nonvolatility and high-density features, such as spintronics, would be a great blessing for the IMC technology. We demonstrate a Pt/Co/NiO device that exhibited multilevel perpendicular exchange bias (EB) with resistive switching (RS) behaviors. It arose from the modulated Co-NiO exchange coupling with the formation/breaking of the conductive filament (CF) within the NiO layer. With atomistic simulation, we show that the multilevel RS stemmed from the modulation of CF size and distribution at the Co−NiO interface, which in turn influenced intermediate levels of EB along the perpendicular direction. It illustrates the possibility of integrating resistive memristors and spintronic devices. Compared with similar studies, our device possesses the advantages of perpendicular magnetic anisotropy and tunable unipolar/bipolar switching.

Neuromorphic Computing with Emerging Antiferromagnetic Ordering in Spin–Orbit Torque Devices

“…Details about the experiments and measurement techniques can be found in section S1 of the Supporting Information. The crystallinity of the NiO-based sputtered heterostructures was characterized by performing grazing incidence wide-angle X-ray scattering (GIWAXS) measurements using a two-dimensional (2D) detector. − Note that GIWAXS is a conventional scattering method commonly used to investigate the crystal structures of thin films. Using angle-resolved data, this method exposes diffraction signals associated with the surface and grain orientations of the sample, covering a range from in-plane to out-of-plane (OOP) directions of the films.…”

“…The ARXRD patterns of samples with a thin NiO layer (2 nm) correspond to the strong polycrystalline nature of Pt, whereas the samples with a thick NiO layer (15 or 30 nm) correspond to NiO polycrystalline planes. 25 , 44 Samples NiO-15 nm and NiO-30 nm presented clear evidence of highly ordered NiO (111) crystallographic planes aligned along the OOP direction (Ψ = 0°). This implies that the crystal orientation tended to align in the perpendicular direction.…”