Formation of transition layers at metal/perovskite oxide interfaces showing resistive switching behaviors

Abstract

Articles you may be interested inCrystallinity dependence of resistive switching in Ti/Pr(Sr0.1Ca0.9)2Mn2O7/Pt: Filamentary versus interfacial mechanisms Appl. Phys. Lett. 104, 093502 (2014); 10.1063/1.4867483 Optimization of resistive switching performance of metal-manganite oxide interfaces by a multipulse protocol J. Appl. Phys. 111, 084512 (2012); 10.1063/1.4705283 Interfacial chemical states of resistance-switching metal/ Pr 0.7 Ca 0.3 MnO 3 interfaces Appl. Phys. Lett. 97, 132111 (2010); 10.1063/1.3496033Electric-field-induced resistance switching universally observed in transition-metal-oxide thin filmsThe authors have investigated the chemical states at the interface of metal=perovskite oxides both with and without bipolar resistive switching (RS) behavior using photoemission spectroscopy and x-ray absorption spectroscopy. Al=Pr 0.7 Ca 0.3 MnO 3 (PCMO), Al=La 0.7 Ca 0.3 MnO 3 (LCMO), and Al=La 0.33 Sr 0.67 FeO 3 interfaces were chosen as typical examples of interfaces for the perovskite-based resistance random access memory (ReRAM), while Pt=PCMO and Ag=LCMO were chosen as references for the metal=perovskite interface without RS behavior. Detailed analyses of spectroscopic data revealed that transition layers were formed at the interfaces showing RS behavior as a result of interfacial redox reactions between the Al electrodes and the transition metal ions in the oxides. On the other hand, for the interfaces that did not exhibit RS behavior, no chemical reaction occurred at the interface. The formation of the interfacial transition layer is naturally explained by considering the redox potential between the electrode materials and transition metal ions. These results suggest that a suitable combination of electrodes and oxides could be designed based on their redox potentials.

Key concepts behind forming-free resistive switching incorporated with rectifying transport properties

“…In general, resistive switching can be categorized into two main types: filamentary type1234 and interface type5678. It has been accepted that filamentary switching is due to the formation of local conductive filaments, which results from the redistribution of oxygen vacancies910 or the diffusion of metal ions 1112.…”

Chemical-state-resolved depth profiles of Al/Pr0.7Ca0.3MnO3 stacked structures for application in resistive switching devices

“…Detailed conditions for film growth and electrode deposition are described elsewhere. 12,13 The bipolar resistive switching behavior in the Al/PCMO interface was confirmed in current-voltage (I-V) measurements. The obtained characteristics were in good agreement with the previous reports.…”

“…5,8,9,12,13 Accumulation of M Mn atoms between the Al metal electrode and Al 2 O 3 interfacial layers strongly suggests that the existence of Mn ions in Al 2 O 3 layers plays an important role in resistive switching. Although the chemical states of Mn ions (Mn 2þ , Mn 3þ , or Mn 4þ ) in the Al 2 O 3 layer are not completely resolved in our present measurements, 21 it is reasonable to consider that Mn 2þ ions in the PCMO x layer are easily diffused into the Al 2 O 3 interfacial layer and the diffused Mn ions are reoxidized to Mn 3þ states 24,25 throughout the Al 2 O 3 interfacial layer as shown in Fig.…”

“…The obtained characteristics were in good agreement with the previous reports. 8,9,13 Atomically flat step-and-terrace structures of Al metal electrodes on the PCMO oxide film surfaces were observed by atomic force microscopy. In order to prevent the surface oxidation of the deposited metal as well as the resultant spurious peaks in the corresponding spectra, we performed oxide film growth, electrode deposition, and subsequent spectroscopic measurements as completely in situ processes.…”

Metallic filament formation by aligned oxygen vacancies in ZnO-based resistive switches

“…8 According to their mechanism, the resistive switches could be categorized into two main types: filamentary type 9-12 and interface type. [13][14][15][16] The general accepted physical model of the filamentary type switch is that the local conductive channel are formed due to the redistribution of oxygen vacancies 17,18 or the diffusion of metal ions in metaloxide. 19,20 For interface type switch, different mechanisms have been proposed, such as charge trapping, 15 or polarization switching 21,22 and others.…”