title: Polytypism in GaAs nanowires: determination of the interplanar spacing of wurtzite GaAs by X-ray diffraction.
abstract: In GaAs nanowires grown along the cubic [111]c direction, zinc blende and wurtzite arrangements have been observed in their stacking sequence, since the energetic barriers for nucleation are typically of similar order of magnitude. It is known that the interplanar spacing of the (111)c Ga (or As) planes in the zinc blende polytype varies slightly from the wurtzite polytype. However, different values have been reported in the literature. Here, the ratio of the interplanar spacing of these polytypes is extracted based on X-ray diffraction measurements for thin GaAs nanowires with a mean diameter of 18-25 nm. The measurements are performed with a nano-focused beam which facilitates the separation of the scattering of nanowires and of parasitic growth. The interplanar spacing of the (111)c Ga (or As) planes in the wurtzite arrangement in GaAs nanowires is observed to be 0.66% ± 0.02% larger than in the zinc blende arrangement.
authors.affiliation: Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Köhl
authors.affiliation: Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Schroth
authors.affiliation: Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Andrey A
authors.initials: AA
authors.lastname: Minkevich
authors.affiliation: Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Jean Wolfgang
authors.initials: JW
authors.lastname: Hornung
authors.affiliation: Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany.
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Dimakis
authors.affiliation: Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany.
authors.forename: Claudio
authors.initials: C
authors.lastname: Somaschini
authors.affiliation: Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany.
authors.forename: Lutz
authors.initials: L
authors.lastname: Geelhaar
authors.affiliation: ANKA, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Timo
authors.initials: T
authors.lastname: Aschenbrenner
authors.affiliation: Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Sergey
authors.initials: S
authors.lastname: Lazarev
authors.affiliation: Laboratory for Application of Synchrotron Radiation, Karlsruhe Institute of Technology, Kaiserstrasse 12, 76131 Karlsruhe, Germany.
authors.forename: Daniil
authors.initials: D
authors.lastname: Grigoriev
authors.affiliation: Solid State Physics, University of Siegen, 57068 Siegen, Germany.
authors.forename: Ullrich
authors.initials: U
authors.lastname: Pietsch
authors.affiliation: Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Tilo
authors.initials: T
authors.lastname: Baumbach
keywords: GaAs; X-ray diffraction; nanofocus; nanowires; polytypism