Polarization structure of nanostrip domain intersections in GeTe films

Boris Croes (1, 2) , Fabien Cheynis (1) , Salia Cherifi Cherifi-Hertel (2) , Kokou Dodzi Dorkenoo (2) , Pierre Müller (1) , Stefano Curiotto (1) , Frédéric Leroy (1)

1 CINaM - Centre Interdisciplinaire de Nanoscience de Marseille
2 IPCMS - Institut de Physique et Chimie des Matériaux de Strasbourg

Ferroelectric germanium telluride is under active consideration for spintronic and thermoelectric applications. The control of the ferroelectric domain walls is a key issue to optimize the electronic and thermal properties of GeTe thin films. Domain walls properties are usually driven by the mechanical and electrostatic compatibility conditions of twin domains. However, in dense ferroelectric domain structures these compatibility conditions are hardly fulfilled everywhere. In particular intersection of domains may result in complex lattice relaxations and polarization textures. In this study, we have fabricated GeTe thin films on silicon substrate and elucidated the intersections of a-type domains using 3D reciprocal space maps, scanning tunneling microscopy, and second-harmonic microscopy. We demonstrate the presence of complex structural reorganizations that manifest by the formation of charged domain walls, large lattice rotations, and enhanced stretching of the rhombohedral lattice.

Mots clés: GeTe; Domain Structure; Ferroelectrics; SHG

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Boris Croes, Fabien Cheynis, Salia Cherifi Cherifi-Hertel, Kokou Dodzi Dorkenoo, Pierre Müller, et al.. Polarization structure of nanostrip domain intersections in GeTe films. Physical Review B, 2024, 109 (2), pp.024103. ⟨10.1103/PhysRevB.109.024103⟩. ⟨hal-04403228⟩