Speaker:
Dr. Rohit Soni
Nanoelektronik, TF
Christian-Albrechts-Universität zu Kiel
Kiel 24143, Germany
Abstract:
For several decades, ferroelectricity has been in the mainstream of modern researches as it has
attracted large attention of a number of researchers in various research fields such as physics,
chemistry, materials science, and electrical engineering. Although ferroelectricity itself has been
vigorously studied for a long time, the subject keeps attracting attention as several
ferroelectricity-related new phenomena have been recently discovered, which are very
interesting from scientific as well as technical perspectives. 1
One of them is the strong effect of ferroelectricity on the electron/spin transport properties of
ferroelectric (FTJs)/multiferroic (MFTJs) tunnel junctions. 1 From a technical perspective,
FTJ/MFTJs are of significant importance as they potentially work as memory elements in
resistance-based future nonvolatile memories. Despite recent advances in experimental and
theoretical studies of FTJs/MFTJs, a substantial number of questions concerning their electrical
behavior still remain open, e.g. the effect of an electrode material and the role of inherent
(microstructural/chemical) asymmetry at the interfaces of the junction on the FTJs/MFTJs
properties.
In this talk, after a brief introduction and an overview of my research activities, I will present my
recent results on FTJs and MFTJs.
First, I'll show that effects from ferroelectric-electrode interfaces can have a strong impact on the
tunneling electroresistance (TER) properties of asymmetric, LSMO/BTO/Au(Cu), FTJs. 2
After that, from my study on epitaxial, LSMO/PZT/LSMO, MFTJs that are nominally
symmetric, I'll show that the inherent asymmetry in the MFTJ (arising from the microstructural
and chemical asymmetry at the interfaces) likely suffices to drive the intertwined TER and TMR
effects. 3 In addition, the tunnel magnetoresistance reversal on polarization switching will be
shown in such MFTJs. 4
References:
1. E. Y. Tsymbal et al. Science 313, 181–183 (2006).
2. R. Soni et al., Nature Communications 5, 5414 (2014).
3. R. Soni et al., Nanoscale 8, 10799 (2016).
4. R. Soni et al. (manuscript in preparation)