Journal ArticleDOI
Toward Truly Single Crystalline GeTe Films: The Relevance of the Substrate Surface
Rui Ning Wang,Jos E. Boschker,E. Bruyer,Domenico Di Sante,Silvia Picozzi,Karthick Perumal,Alessandro Giussani,Henning Riechert,Raffaella Calarco +8 more
TLDR
In this article, the growth of GeTe thin films on a Si(111)-(√3 × √3)R30°-Sb surface is reported, and the formation of rotational domains in GeTe grown on Si(7 × 7) is explained by domain matched coincidence lattice formation with the Si(1 × 1) surface.Abstract:
The growth of GeTe thin films on a Si(111)-(√3 × √3)R30°-Sb surface is reported. At growth onset, the rapid formation of fully relaxed crystalline GeTe(0001)-(1 × 1) is observed. During growth, a GeTe(0001)-(√3 × √3)R30° surface reconstruction is also detected. Indeed, density functional theory (DFT) simulations indicate that the reconstructed GeTe(0001)-(√3 × √3)R30° structure is energetically competing with the GeTe(0001)-(1 × 1) reconstruction. The out-of-plane α-GeTe ||Si and in-plane α-GeTe ||Si epitaxial relationships are confirmed by X-ray diffraction (XRD). Suppression of rotational twist and reduction of twinned domains are achieved. The formation of rotational domains in GeTe grown on Si(111)-(7 × 7) is explained by domain matched coincidence lattice formation with the Si(111)-(1 × 1) surface. Atomic force microscopy (AFM) images show the coalescence of well-oriented islands with subnanometer roughness on their top part. van der Pauw measurements are performed to verify the...read more
Citations
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Journal ArticleDOI
Giant Rashba‐Type Spin Splitting in Ferroelectric GeTe(111)
Marcus Liebmann,Christian Rinaldi,Domenico Di Sante,Jens Kellner,Christian Pauly,Rui Ning Wang,Jos E. Boschker,Alessandro Giussani,Stefano Bertoli,Matteo Cantoni,Lorenzo Baldrati,Marco Asa,Ivana Vobornik,Giancarlo Panaccione,Dmitry Marchenko,Jaime Sánchez-Barriga,Oliver Rader,Raffaella Calarco,Silvia Picozzi,Riccardo Bertacco,Markus Morgenstern +20 more
TL;DR: Photoelectron spectroscopy in combination with piezoforce microscopy reveals that the helicity of Rashba bands is coupled to the nonvolatile ferroelectric polarization of GeTe(111).
Journal ArticleDOI
Interface formation of two- and three-dimensionally bonded materials in the case of GeTe-Sb2Te3 superlattices
Jamo Momand,Rui Ning Wang,Jos E. Boschker,Marcel A. Verheijen,Raffaella Calarco,Bart J. Kooi +5 more
TL;DR: Contrary to the previously proposed models, it is found that the ground state of the film actually consists of van der Waals bonded layers of Sb2Te3 and rhombohedral GeSbTe, and it is shown by annealing the film at 400 °C, which reconfigures the superlattice into bulk rhombo Cathedral GeTe, that this van Der Waals layer is thermodynamically favored.
Journal ArticleDOI
Ferroelectric Control of the Spin Texture in GeTe
Christian Rinaldi,Sara Varotto,Marco Asa,Jagoda Sławińska,Jun Fujii,Giovanni Vinai,Stefano Cecchi,Domenico Di Sante,Raffaella Calarco,Ivana Vobornik,Giancarlo Panaccione,S. Picozzi,Riccardo Bertacco +12 more
TL;DR: Based on the intimate link between ferroelectric polarization and spin in GeTe, ferro electric patterning paves the way to the investigation of devices with engineered spin configurations.
Journal ArticleDOI
Phase-Change Superlattice Materials toward Low Power Consumption and High Density Data Storage: Microscopic Picture, Working Principles, and Optimization
TL;DR: In this article, the authors summarized the broad applications of phase-change materials and proposed strategies on material optimizations to further enhance device performances, and an outlook on new applications with these advanced superlattice materials is suggested.
Journal ArticleDOI
Dynamic reconfiguration of van der Waals gaps within GeTe-Sb2Te3 based superlattices
Jamo Momand,Rui Ning Wang,Jos E. Boschker,Marcel A. Verheijen,Raffaella Calarco,Bart J. Kooi +5 more
TL;DR: The structural organization of van der Waals gaps commonly encountered in GeSbTe alloys are illuminated, which are intimately related to their electronic properties and the metal-insulator transition.
References
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Journal ArticleDOI
7 × 7 Reconstruction on Si(111) Resolved in Real Space
TL;DR: In this paper, a modified adatom model with 12 adatoms per unit cell and an inhomogeneously relaxed underlying top layer was used for Si(111) reconstruction.
Journal ArticleDOI
Resonant bonding in crystalline phase-change materials
TL;DR: Measurements of the dielectric function in the energy range from 0.025 to 3 eV reveal that the optical dielectrics constant is 70-200% larger for the crystalline than the amorphous phases.
Journal ArticleDOI
Interfacial phase-change memory
Robert E. Simpson,Paul Fons,Alexander V. Kolobov,Toshio Fukaya,Milos Krbal,Takashi Yagi,Junji Tominaga +6 more
TL;DR: GeTe/Sb(2)Te(3) interfacial phase-change memory (IPCM) data storage devices with reduced switching energies, improved write-erase cycle lifetimes and faster switching speeds are demonstrated.
Journal ArticleDOI
A map for phase-change materials.
Dominic Lencer,Martin Salinga,Blazej Grabowski,Tilmann Hickel,Jörg Neugebauer,Matthias Wuttig +5 more
TL;DR: A first treasure map for phase-change materials is presented on the basis of a fundamental understanding of the bonding characteristics, spanned by two coordinates that can be calculated just from the composition, and represent the degree of ionicity and the tendency towards hybridization ('covalency') of the bonded materials.
Journal ArticleDOI
Domain epitaxy: A unified paradigm for thin film growth
Jagdish Narayan,B. C. Larson +1 more
TL;DR: In this paper, a unified model for thin film epitaxy where single crystal films with small and large lattice misfits are grown by domain matching epitaxy (DME) is presented.