001     903305
005     20220114093231.0
020 _ _ |a 978-3-95806-592-5
024 7 _ |2 Handle
|a 2128/29387
037 _ _ |a FZJ-2021-05001
041 _ _ |a English
100 1 _ |0 P:(DE-Juel1)168371
|a Wilhelm, Marek
|b 0
|e Corresponding author
|g male
|u fzj
245 _ _ |a Photoemission electron microscopy of magneto-ionic effects in La$_{0.7}$Sr$_{0.3}$MnO$_{3}$
|f - 2021-11-04
260 _ _ |a Jülich
|b Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag
|c 2021
300 _ _ |a 134 S.
336 7 _ |2 DataCite
|a Output Types/Dissertation
336 7 _ |0 PUB:(DE-HGF)3
|2 PUB:(DE-HGF)
|a Book
|m book
336 7 _ |2 ORCID
|a DISSERTATION
336 7 _ |2 BibTeX
|a PHDTHESIS
336 7 _ |0 2
|2 EndNote
|a Thesis
336 7 _ |0 PUB:(DE-HGF)11
|2 PUB:(DE-HGF)
|a Dissertation / PhD Thesis
|b phd
|m phd
|s 1638962879_27262
336 7 _ |2 DRIVER
|a doctoralThesis
490 0 _ |a Schriften des Forschungszentrums Jülich. Reihe Schlüsseltechnologien / Key Technologies
|v 249
502 _ _ |a Universität Duisburg, Diss., 2021
|b Dissertation
|c Universität Duisburg
|d 2021
520 _ _ |a One of the most challenging tasks in future nanoelectronics is the realization of novel low-power consumption devices for the application in non-volatile memories, processing, transduction and sensing units. Electric-field-control of the magnetism, which is based on the $\textit{magnetoelectric}$ (ME) effect, may pave the way towards an alternative concept to Si-based electronics relying on dissipative electrical currents. Numerous studies reported on magnetoelectric materials showing ME coupling via strain, charge carrier doping and interfacial exchange processes. Recently, the field of magneto-ionics received increased attention as the voltage-driven chemical intercalation of ionic species opened a novel route towards the control of magnetism in bulk materials. This thesis reports on electric-field-induced magnetic switching in a La$_{0.7}$Sr$_{0.3}$MnO$_{3}$(LSMO) thin film prototype system. As a strongly correlated magnetic oxide LSMO can appear in multiple magnetic states depending on the prevalent oxidation state of the manganese cations. The migration of oxygen vacancies and the local redistribution of the oxygen concentration profoundly alters the balance of the double-exchange and superexchange interactions between manganese and oxygen ions, thus providing a granular control of chemical, structural and magnetic phase transitions. 10nm thick La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ films were epitaxially grown on TiO$_{2}$-terminated Nb(0.5%):SrTiO$_{3}$ (001) substrates by means of $\textit{pulsed laser deposition}$ (PLD). The morphology and the crystal structure were characterized by atomic force microscopy (AFM) and X-ray diffraction (XRD) revealing an epitaxial, single crystalline film and an atomically flat surface. Vibrating sample magnetometry (VSM) and $\textit{X-ray magnetic circular dichroism}$ (XMCD) were used to investigate the magnetic properties. Further, the electronic structure and the chemical properties were probed by $\textit{hard X-ray photoemission spectroscopy}$ (HAXPES) and $\textit{X-ray absorption spectroscopy}$ (XAS). $\textit{Local conductivity atomic force microscopy}$ (LC-AFM) was utilized to electrically modulate the resistance of LSMO thin films. To investigate the micro-scale redox processes present in the electrically modified areas, we performed a combined and element-selective $\textit{X-ray photoemission electron microscopy}$ (XPEEM) study in XAS and XMCD mode. The results demonstrate the direct interplay between resistivity, chemical composition, and magnetic ordering driven by an oxygen exchange process across the LSMO film surface. Significant chemical modifications are observed in the high resistive state, where the incorporation of oxygen vacancies leads to a distinct valence change from Mn$^{3+/4+}$ to Mn$^{2+/3+}$. Further, a direct correlation between oxygen deficiency and a degradation of the ferromagnetic properties is found. In this light, the results of this thesis provide novel insights into the vacancy-driven magneto-ionic control of magnetoelectric oxides for the example LSMO. Moreover, they open up novel routes towards a multiphase-control of physical and chemical properties in magnetic oxides and novel ionotronic devices.
536 _ _ |0 G:(DE-HGF)POF4-5215
|a 5215 - Towards Quantum and Neuromorphic Computing Functionalities (POF4-521)
|c POF4-521
|f POF IV
|x 0
856 4 _ |u https://juser.fz-juelich.de/record/903305/files/Schluesseltech_249.pdf
|y OpenAccess
909 C O |o oai:juser.fz-juelich.de:903305
|p openaire
|p open_access
|p VDB
|p driver
|p dnbdelivery
910 1 _ |0 I:(DE-588b)5008462-8
|6 P:(DE-Juel1)168371
|a Forschungszentrum Jülich
|b 0
|k FZJ
913 1 _ |0 G:(DE-HGF)POF4-521
|1 G:(DE-HGF)POF4-520
|2 G:(DE-HGF)POF4-500
|3 G:(DE-HGF)POF4
|4 G:(DE-HGF)POF
|9 G:(DE-HGF)POF4-5215
|a DE-HGF
|b Key Technologies
|l Natural, Artificial and Cognitive Information Processing
|v Quantum Materials
|x 0
914 1 _ |y 2021
915 _ _ |0 StatID:(DE-HGF)0510
|2 StatID
|a OpenAccess
915 _ _ |0 LIC:(DE-HGF)CCBY4
|2 HGFVOC
|a Creative Commons Attribution CC BY 4.0
920 _ _ |l yes
920 1 _ |0 I:(DE-Juel1)PGI-6-20110106
|k PGI-6
|l Elektronische Eigenschaften
|x 0
980 _ _ |a phd
980 _ _ |a VDB
980 _ _ |a UNRESTRICTED
980 _ _ |a book
980 _ _ |a I:(DE-Juel1)PGI-6-20110106
980 1 _ |a FullTexts


LibraryCollectionCLSMajorCLSMinorLanguageAuthor
Marc 21