1:30 PM - 1:45 PM
[13p-N203-1] Electronic structure measurements of Pt/AlFeO3/Nb:SrTiO3 hetero-film for resistance switching material by high resolution X-ray absorption spectroscopy
Keywords:resistive switching, high energy resolution XAS
In 2020, a resistance switching phenomenon was reported in a Pt/AlFeO3/Nb:SrTiO3 hetero-film. Since the structure of the film is so simple that it is expected to be used in a high-density memory device with 3D integrated structures. Among several proposed mechanisms, we claim that the redox reaction of Fe2+/Fe3+ at the Pt/AlFeO3 interface is essential for resistive switching.
In this study, high-energy resolution fluorescence-detection X-ray absorption spectroscopy was performed to observe the change in the Fe valence state. Given the creation and annihilation of the oxygen vacancy under resistive switching, a slight energy shift of the pre-edge peak and/or appearance of a shoulder structure are expected base on the theoretical simulation. However, no such feature was found in experimental spectra. This clearly concludes that the so-called “filament model”, in which oxygen vacancies partially short-circuit the upper and lower electrodes, are excluded from switching models.
In this study, high-energy resolution fluorescence-detection X-ray absorption spectroscopy was performed to observe the change in the Fe valence state. Given the creation and annihilation of the oxygen vacancy under resistive switching, a slight energy shift of the pre-edge peak and/or appearance of a shoulder structure are expected base on the theoretical simulation. However, no such feature was found in experimental spectra. This clearly concludes that the so-called “filament model”, in which oxygen vacancies partially short-circuit the upper and lower electrodes, are excluded from switching models.