DC Field | Value | Language |
---|---|---|
dc.contributor.author | Lee, N | - |
dc.contributor.author | Lansac, Y | - |
dc.contributor.author | Hwang, H | - |
dc.contributor.author | Jang, YH | - |
dc.date.accessioned | 2017-07-19T12:22:55Z | - |
dc.date.available | 2017-07-19T12:22:55Z | - |
dc.date.created | 2016-02-12 | - |
dc.date.issued | 2015-01 | - |
dc.identifier.issn | 2046-2069 | - |
dc.identifier.uri | https://oasis.postech.ac.kr/handle/2014.oak/35750 | - |
dc.description.abstract | Resistance random access memory is a promising next-generation non-volatile memory device due to its simple capacitor-like structure, ultrafast switching, and extended retention. A composite thin film of perovskite oxide such as La1-xSrxMnO3 (LSMO) and reactive metal such as aluminum (Al) is a key material for such device, but lack of clear understanding of its microscopic switching mechanism hampers further development along this direction. We therefore carry out a series of density functional theory calculations tracking down a molecular-level hypothesis of the switching process: (1) oxygen vacancy (V-O) formation in LSMO and migration through LSMO towards the interface with Al and (2) AlOx oxide formation at the interface. As the first step of this series of effort, Al/LSMO/Al model junction devices are built to represent four different oxygen-deficiency levels of LSMO, and their structure, energy, electronic structure, and current-voltage characteristics are calculated and compared. We find that the V-O formation in LSMO itself plays an interesting role in the resistive switching of the junction by initially reducing the number of majority-spin states around the Fermi level (becoming more insulating as expected) and then by increasing the number of minority-spin states through Mn-V-O-Mn-V-O filament-like pathways developed in the film (surprisingly becoming more conducting than stoichiometric LSMO). Assessment of the importance of this effect would require a comparison with the ON/OFF ratio induced by AlOx formation, which will be done separately in the second step of our effort, but the control of the oxygen deficiency appears to be a very important and challenging task required for reliable device fabrication and operation. The calculation also shows that, at sufficiently high doping level x, the V-O formation energy is reasonably low and the V-O migration energy barrier is even lower, explaining the fast switching of this type of devices. On the other hand, the calculated energy barrier is high enough to avoid thermal random-walk O migration which could refill V-O sites, explaining the extended retention of such devices. | - |
dc.language | English | - |
dc.publisher | ROYAL SOC CHEMISTRY | - |
dc.relation.isPartOf | RSC ADVANCES | - |
dc.subject | Engineering main heading: Substrate integrated waveguides | - |
dc.title | Switching mechanism of Al/La1-xSrxMnO3 resistance random access memory. I. Oxygen vacancy formation in perovskites | - |
dc.type | Article | - |
dc.identifier.doi | 10.1039/C5RA21982E | - |
dc.type.rims | ART | - |
dc.identifier.bibliographicCitation | RSC ADVANCES, v.5, no.124, pp.102772 - 102779 | - |
dc.identifier.wosid | 000366162300081 | - |
dc.date.tcdate | 2019-03-01 | - |
dc.citation.endPage | 102779 | - |
dc.citation.number | 124 | - |
dc.citation.startPage | 102772 | - |
dc.citation.title | RSC ADVANCES | - |
dc.citation.volume | 5 | - |
dc.contributor.affiliatedAuthor | Hwang, H | - |
dc.identifier.scopusid | 2-s2.0-84948809295 | - |
dc.description.journalClass | 1 | - |
dc.description.journalClass | 1 | - |
dc.description.wostc | 3 | - |
dc.description.scptc | 3 | * |
dc.date.scptcdate | 2018-05-121 | * |
dc.type.docType | Article | - |
dc.subject.keywordPlus | LA0.7SR0.3MNO3 THIN-FILMS | - |
dc.subject.keywordPlus | ELASTIC BAND METHOD | - |
dc.subject.keywordPlus | GIANT MAGNETORESISTANCE | - |
dc.subject.keywordPlus | ELECTRONIC-STRUCTURE | - |
dc.subject.keywordPlus | RESISTIVE MEMORY | - |
dc.subject.keywordPlus | NEUTRON-DIFFRACTION | - |
dc.subject.keywordPlus | MAGNETIC-PROPERTIES | - |
dc.subject.keywordPlus | CRYSTAL-STRUCTURE | - |
dc.subject.keywordPlus | ROOM-TEMPERATURE | - |
dc.subject.keywordPlus | ION MIGRATION | - |
dc.relation.journalWebOfScienceCategory | Chemistry, Multidisciplinary | - |
dc.description.journalRegisteredClass | scie | - |
dc.description.journalRegisteredClass | scopus | - |
dc.relation.journalResearchArea | Chemistry | - |
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