Book/Dissertation / PhD Thesis

FZJ-2022-02846

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Magnetoelectric Interactions in Multiferroic Thin-film Heterosystems and Nanostructures

Gökdemir, H. (Corresponding author)FZJ*

2022
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich
ISBN: 978-3-95806-635-9

Please use a persistent id in citations: http://hdl.handle.net/2128/31587

Abstract: Electric-write magnetic-read memory-based devices replace conventionalhard-disk drives, since they o↵er an advantage of reduced power consumptionfor writing. The next generation spintronic application building blocksare multiferroic materials, which combine and couple magnetic and electricproperties. It was therefore of great importance to investigate the still unexploredphenomena, such as electronic structure changes at the interfacesof these heterosystems. Within the scope of this thesis, we have attemptedto develop artificial multiferroic (AM) materials with desired ferroic properties.We studied two model systems:• (i) BaTiO3/La0.7Sr0.3MnO3/SrTiO3 (BTO/LSMO/STO) and• (ii) Fe/BaTiO3 (Fe/BTO).Firstly, epitaxially grown BTO and LSMO films on STO grown by thepulsed laser deposition (PLD) technique were investigated. Magnetic properties,surface morphologies, and crystal phases of the as-received sampleswere characterized. To study charge anisotropy and coupling of two ferroicorders of the AM heterostructures element specifically we performedX-ray absorption spectroscopy (XAS) measurements with polarized X-raysat UE56/1 − SGM FZ J¨ulich Beamline at BESSY-II synchrotron facility.Secondly, the Fe/BTO system is investigated using a cutting-edge spectromicroscopictool, namely the low energy electron microscope/X-ray photoelectronemission microscope (LEEM/XPEEM) located at the same endstationat BESSY-II. LEEM, Auger electron spectroscopy (AES) and lowenergy electron di↵raction (LEED) were used to study the ferroelectric domains,cleanness and termination of the BTO(001) surface, respectively.Spatially resolved electronic structure of ferroelectric domains were demonstratedfor the first time using X-ray linear dichroism (XLD)-PEEM contrastmechanism. In−situ and ex−situ Fe growth by e-beam evaporationon BTO(001) was established. To present the interplay between ferroelectricityand inverse magnetostrictive behavior in Fe/BTO, X-ray magneticcircular dichroism (XMCD)- and XLD-PEEM experiments were conducted

Note: Dissertation, Univ. Duisburg, 2021

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Contributing Institute(s):

1. Elektronische Eigenschaften (PGI-6)

Research Program(s):

1. 5221 - Advanced Solid-State Qubits and Qubit Systems (POF4-522) (POF4-522)

Appears in the scientific report 2022

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