Three-Dimensional Structure of Twinned and Zigzagged One-Dimensional Nanostructures Using Electron Tomography

Abstract

Electron tomography and high-resolution transmission electron microscopy were used to characterize the unique three-dimensional (3D) structures of twinned Zn(3)P(2) (tetragonal) and InAs (zinc blende) nanowires synthesized by the vapor transport method. The Zn(3)P(2) nanowires adopt a unique superlattice structure that consists of twinned octahedral slice segments having alternating orientations along the axial [111] direction of a pseudo cubic unit cell. The apexes of the octahedral slice segment are indexed as six equivalent <112> directions at the [111] zone axis. At each 30 degrees turn, the straight and zigzagged morphologies appear repeatedly at the <112> and <011> zone axes, respectively. The 3D structure of the twinned Zn(3)P(2) nanowires is virtually the same as that of the twinned InAs nanowires. In addition, we analyzed the 3D structure of zigzagged CdO (rock salt) nanowires and found that they include hexahedral segments, whose six apexes are matched to the <011> directions, linked along the [111] axial direction. We also analyzed the unique 3D structure of rutile TiO(2) (tetragonal) nanobelts; at each 90 degrees turn, the straight morphology appears repeatedly, while the in-between twisted form appears at the [011] zone axis. We suggest that the TiO(2) nanobelts consist of twinned octahedral slices whose six apexes are indexed by the <011>/<001> directions with the axial [010] direction.

Zn3P2–Zn3As2 Solid Solution Nanowires

“…42 The superlattice structure was also efficiently formed if the bare Si substrates (no Au deposited) were used. Therefore, another series of Zn 3 (P 1−x As x ) 2 NWs were synthesized by the thermal evaporation of Zn/InP/InAs powders.…”

“…43−45 The present structure is identical to that of the III−V NWs. 42 The (002) planes of hexagonal-phase Zn 3 P 2 constitute the twin planes, which allow the alternate stacking of the cubic-phase twin segments. Therefore, the twinned superlattice results from the periodic production of hexagonal phases during growth.…”

Doping Effects on Polytypism in Semiconductor Nanowires: A First-Principles Study

“…The optimization of crystal quality and crystal phase control lead to successful demonstration of nanowire-based devices such as photovoltatic cells [1,2], photo detectors [3], laser diodes [4], and transistors [5,6]. Recently, periodic arrangements of twin planes such as twin-plane superlattices have been reported for a variety of group III-V semiconductor NW systems such as InAs [7][8][9][10], InP [11][12][13][14], and GaAs NWs [15]. The crystal structure of InP NWs has been now controlled by Zn doping during the vapor-liquid-solid (VLS) growth: the addition of small amounts of Zn to vapor phase results in the growth of NWs with ZB structure [13][14][15][16][17][18].…”

Structure-property relationships in self-assembled metalorganic chemical vapor deposition–grown CoFe2O4–PbTiO3 multiferroic nanocomposites using three-dimensional characterization

“…13 Electron tomography is a method that can reconstruct the 3 D shape of an object from a series of two-dimensional projections recorded at different view angles, 11,14 with a spatial resolution on the order of $1 nm, a field of view of at least hundreds of nanometers, and the versatility to investigate microstructure and composition or diffraction information at the same time. 11,[15][16][17] It is therefore an ideal technique to investigate both the morphology and chemistry of two-phase multiferroic nanocomposites on the nanoscale. Vector piezoresponse force microscopy (v-PFM) can be used to image local electromechanical responses, which are related to crystallographic orientation by piezoelectricity, 18 so v-PFM complements the microstructural information obtained by the transmission electron microscopy (TEM) techniques.…”