Twin domain imaging in topological insulator Bi₂Te₃ and Bi₂Se₃ epitaxial thin films by scanning X-ray nanobeam microscopy and electron backscatter diffraction

Abstract

was imaged by electron backscatter diffraction (EBSD) and scanning X-ray diffraction microscopy (SXRM). The crystal orientation at the surface, determined by EBSD, is correlated with the surface topography, which shows triangular pyramidal features with edges oriented in two different orientations rotated in the surface plane by 60. The bulk crystal orientation is mapped out using SXRM by measuring the diffracted X-ray intensity of an asymmetric Bragg peak using a nano-focused X-ray beam scanned over the sample. By comparing bulkand surface-sensitive measurements of the same area, buried twin domains not visible on the surface are identified. The lateral twin domain size is found to increase with the film thickness.

Studies on the origin of the interfacial superconductivity of Sb 2 Te 3 /Fe 1+y Te heterostructures

“…Reflection high-energy electron diffraction (RHEED) patterns were captured after the growth of Fe1+yTe and Sb2Te3 layers. Figure 1a The epitaxial growth of bismuth and antimony chalcogenides on substrates that have six-fold symmetry, such as Al2O3(0001) 22 , Si(111) 23 , BaF2(111) 24,25 InP(111) 26 and GaAs(111) 27 , usually results in two mirror-symmetric twin domains due to the fact that there are two stacking sequences (ABCAB and ACBAC) along the [0001] direction for one QL of these chalcogenides.…”

Ferroelectric Self-Poling in GeTe Films and Crystals

“…The angular resolution was defined by a sample to detector distance of 530 mm and the 55 µm pitch of the 516 × 516 detector pixels. This procedure results in a 2D position dependent mapping of the diffracted intensity as described in detail by Chahine et al [27] and was previously successfully applied to thin layers and nanostructures [28][29][30][31][32]. Employing an additional sample rotation, a five-dimensional data set I(x, y, Q x , Q y , Q z ), comprising two real space and three reciprocal space coordinates, is obtained.…”

Magnetotransport in Bi2Se3 thin films epitaxially grown on Ge(111)

“…In-plane and out-of-plane x-ray diffraction (XRD) measurements were performed with two different diffractometers. The grazing incidence X-ray diffraction (GIXD) was done with a SmartLab Rigaku diffractometer equipped with a copper rotating anode beam tube [20]. Indeed, the ABCAB and ACBAC stackings of the quintuple layer structure give inplane diffraction peaks {hk0} at the same positions.…”