BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//UNIFR/WEBMASTER//NONSGML v1.0//EN
CALSCALE:GREGORIAN
BEGIN:VEVENT
DTSTART;VALUE=DATE:20251027T151500
DTEND;VALUE=DATE:20251027T151500
UID:18752@agenda.unifr.ch
DESCRIPTION:The pursuit for new materials to form the basis for future energy-efficient electronics has\nbrought forward transition-metal oxides that offer a broad range of potentially coexisting\nfunctionalities. Ferroelectric oxides distinguished by the presence of a non-volatile electric\npolarization that can be switched by an electric field are especially promising for the\ndevelopment of novel electronic devices with reduced power consumption. Despite\nhaving found countless commercial applications owing to their concomitant piezo- and\npyroelectric properties, the integration of ferroelectric oxides into next-generation\nmemory and logic devices is however, still facing difficulties. Notably, when prepared in\nthe form of technologically relevant thin films and heterostructures achieving a\ndeterministic arrangement of domains - the basic functional entities of ferroelectric\nmaterials are rendered challenging by the competing effects of various interactions, such\nas strain, electrostatic, and defect chemistry. In our work, we pave the way toward the\ndesign of tailored ferroelectric domain configurations in epitaxial thin films by tracking and\ncontrolling domains at the point of their emergence – during thin-film growth. With the\ndirect in-situ access to the functional property of ferroelectrics using non-linear optics we\nmanage to unravel the mechanisms that drive the formation of domains in prototypical\nferroelectric oxides and put forward design strategies to realize highly specialized domain\nconfigurations. In thin films of the archetypal ferroelectrics PbTi03 and Pb(ZrxTi1-x)03 (PZT),\nwe discover that tensile epitaxial strain induces the formation of in-plane-oriented\ndomains within an out-of-planeoriented matrix already during thin-film growth [1]. We\nfurther uncover that the epitaxial growth conditions can significantly affect the\nconcentration of charged defects, which determines the electrostatics during growth\nand, hence, provides us with a handle to control the direction of the polarization [2].\nMaking use of these in-situ observations we then tailor the elastic and electrostatic\nboundary conditions in PZT thin to obtain a nanoscale domain configuration exhibiting\nnonbinary switching characteristics [3], which ~is essential for applications in brain-inspired\nneuromorphic computing. Finally, we explore the use of light as a remote trigger to\noptically manipulate the fell'oelectric polarization and find that above-bandgap optical\nexcitation can strongly alter the charge screening in ferroelectric heterostructures [4].\nDepending on the ferroelectric domain configuration this can prompt a transient\nmodification of the polarization or even non-volatile poling, constituting a major step\ntoward all-optical control of ferroelectricity.\n[1] M.F. Sarott et al. Appl. Phys. Lett. 117, 132901 (2020)\n[2] M.F. Sarott et al. Adv. Funct. Mater. 33 . 22 14849 (2023)\n[3] M.F. Sarott et al. Nat. Commun . 13, 3159 2022)\n[4] M.F. Sarott et al. Adv . Mater. 36, 2312437 (2024)
SUMMARY:Designing ferroelectric domain configurations in epitaxial thin films using strain, electrostatics, and light
CATEGORIES:Séminaire
LOCATION:PER 08\, 0.51\, Chemin du Musée 3\, 1700 Fribourg
URL;VALUE=URI:https://agenda.unifr.ch/e/fr/18752
END:VEVENT
END:VCALENDAR