Seminar
| Date | 2024-03-07 |
|---|---|
| Time | 14:00 |
| Title | Pushing the frontiers in the thin film epitaxy of functional oxides |
■ Title : Pushing the frontiers in the thin film epitaxy of functional oxides
■ Speakers : Dr. Jieun Kim (Univ. of Wisconsin-Madison)
■ Date : 2024. 3. 7(Thu), 14:00 ~ 15:00
■ Venue : W1-1, #2430 (주흘회의실)
■ Abstract :
Understanding materials structures and how they give rise to their properties is the core mission of materials research. Owing to the ability to produce atomically precise thin films, epitaxial growth offers unparalleled opportunities to produce designer artificial heterostructures in the pursuit of deeper physical understanding and novel phenomena. In this talk, I will discuss how the synthesis of model systems, coupled with multi-modal experimental and computational approaches leads to new understanding of old materials and what the future holds for the development of new synthesis approaches towards more perfect materials.
First, I will discuss the recent advances unveiling the physical mechanisms behind the ultrahigh piezoelectricity of the model relaxor ferroelectric 0.68PbMg1/3Nb2/3O3-0.32PbTiO3 (PMN-PT). Using a multi-scale approach that probes the structural evolution in both the average unit-cells and polar nanodomains, I will show that polar nanodomains play a more direct role in polarization rotation than previously perceived. Second, I will present a hybrid epitaxial growth technique combining molecular-beam epitaxy (MBE) and pulsed-laser deposition (PLD), namely the hybrid PLD, for the growth of complex oxides such as KTaO3, which presents significant processing challenges due to extreme vapor pressure mismatch. Superconducting heterostructures based on electronic-grade epitaxial (111) KTaO3 thin films allow two-dimensional electron gas at the heterointerface between amorphous LaAlO3 and KTaO3 thin film to exhibit superior electronic transport properties than those of bulk single crystal KTaO3-based heterostructures. Finally, I will present interesting future avenues that can be unlocked by advanced hybrid growth techniques