Thick does the trick: genesis of ferroelectricity in 2D GeTe-rich (GeTe).sub.m./sub.(Sb.sub.2./sub.Te.sub.3./sub.).sub.n./sub. lamellae

0585018 - FZÚ 2025 RIV US eng J - Journal Article
Cecchi, S. - Momand, J. - Dragoni, D. - Abou El Kheir, O. - Fagiani, F. - Kriegner, Dominik - Rinaldi, C. - Arciprete, F. - Holý, V. - Kooi, B.J. - Bernasconi, M. - Calarco, R.
Thick does the trick: genesis of ferroelectricity in 2D GeTe-rich (GeTe)_m(Sb₂Te₃)_n lamellae.
Advanced Science. Roč. 11, č. 1 (2024), č. článku 2304785. E-ISSN 2198-3844
R&D Projects: GA ČR(CZ) GM22-22000M
Grant - others:AV ČR(CZ) LQ100102201
Program: Prémie Lumina quaeruntur
Institutional support: RVO:68378271
Keywords : 2D ferroelectrics * van der Waals * molecular beam epitaxy * phase-change materials * density functional theory calculations
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 15.1, year: 2022
Method of publishing: Open access

The possibility to engineer (GeTe)m(Sb2Te3)n phase-change materials to co-host ferroelectricity is extremely attractive. The combination of these functionalities holds great technological impact, potentially enabling the design of novel multifunctional devices. Here an experimental and theoretical study of epitaxial (GeTe)m(Sb2Te3)n with GeTe-rich composition is presented. These layered films feature a tunable distribution of (GeTe)m(Sb2Te3)1 blocks of different sizes. Breakthrough evidence of ferroelectric displacement in thick (GeTe)m(Sb2Te3)1 lamellae is provided. The density functional theory calculations suggest the formation of a tilted (GeTe)m slab sandwiched in GeTe-rich blocks. That is, the net ferroelectric polarization is confined almost in-plane, representing an unprecedented case between 2D and bulk ferroelectric materials. The ferroelectric behavior is confirmed by piezoresponse force microscopy and electroresistive measurements.
Permanent Link: https://hdl.handle.net/11104/0352787