Table 1 In situ characterization techniques for investigating the switching mechanism in memristors

Diffraction-limited confocal microscopy¹⁷⁴

Visual inspection of features in the channel including filaments and dendrites

50 μm–100 μm

hours

In-situ C-AFM^33,38

IV measurement, location of conductive filament, filament morphology and topography

10 nm–10 μm

100 ms-days

In-situ K-PFM³³

Vacancy dynamics, quantification of vacancies, trapping/de-trapping of space charge and surface potential

10 nm–10 μm

100 ms-days

In-situ Photoluminescence Spectroscopy¹⁷⁴

Localized oxidation of filament during switching

1 μm–10 μm

100 ms-hours

In-situ Thermal Imaging¹⁷⁴

Spatial mapping of local temperature

5 μm–10 μm

hours