The rational design of a Au(I) precursor for focused electron beam induced deposition

• Ali Marashdeh,
• Thiadrik Tiesma,
• Niels J. C. van Velzen,
• Sjoerd Harder,
• Remco W. A. Havenith,
• Jeff T. M. De Hosson and
• Willem F. van Dorp

Beilstein J. Nanotechnol. 2017, 8, 2753–2765, doi:10.3762/bjnano.8.274

• Al signal and the ring structure come from the supporting Al stub. DFT calculations on isolated molecules Figure 6 and Figure 7 show that ClAuCO is unstable in vacuum, decomposing rapidly to AuCl, while ClAuPMe3 and MeAuPMe3 are stable. To understand why the stability of these compounds varies so

• enough to be used as a precursor for chemical vapor or electron-induced deposition [12][51][52]. Concluding, the DFT calculations of the ground states of isolated molecules help to explain the stability of ClAuPF3, CF3AuCO and ClAuPMe3. MeAuPMe3 appears to be stabilized by a significant activation

• , the SEM analysis, the DFT calculations and the XRD measurements, we now understand the stability and volatility of Au(I) complexes at the molecular level. Regarding ClAuCO, DFT calculations on isolated molecules show that they are stabilized by at least +25.5 kcal/mol. On the other hand, periodic DFT

Ab initio study of adsorption and diffusion of lithium on transition metal dichalcogenide monolayers

• Xiaoli Sun and
• Zhiguo Wang

Beilstein J. Nanotechnol. 2017, 8, 2711–2718, doi:10.3762/bjnano.8.270

• with high electronic and ion mobility and large energy storage capacity. Conclusion Using density functional theory (DFT) simulations, the stability and electronic properties of MX2 monolayers were investigated. TiX2, VSe2, CrX2, ZrX2 and HfX2 are energetically favourable in the 1T phase, and 1T-VS2

• . Simulation Details All the spin-polarized DFT calculations were performed with SIESTA code [62], in which norm-conserving pseudopotentials and a Perdew–Burcke–Ernzerhof functional was used to describe the electron–ion interaction and electron exchange correlation, respectively. Numerical atomic orbits were

Synthesis of [{AgO₂CCH₂OMe(PPh₃)}_n] and theoretical study of its use in focused electron beam induced deposition

• Jelena Tamuliene,
• Julian Noll,
• Peter Frenzel,
• Tobias Rüffer,
• Alexander Jakob,
• Bernhard Walfort and
• Heinrich Lang

Beilstein J. Nanotechnol. 2017, 8, 2615–2624, doi:10.3762/bjnano.8.262

• conditions was studied by DFT (B3LYP) calculations on monomeric [AgO2CCH2OMe(PPh3)]. At an energy of the secondary electrons up to 0.8 eV elimination of PPh3 occurs, giving Ag+ and O2CCH2OMe−. Likewise, by release of PPh3 from [AgO2CCH2OMe(PPh3)] the fragment [AgO2CCH2OMe]− is formed from which Ag+ and

• O2CCH2OMe− is generated, further following the first fragmentation route. However, at 1.3 eV the initial step is decarboxylation giving [AgCH2OMe(PPh3)], followed by Ag–P and Ag–C bond cleavages. Keywords: DFT; DSC; FEBID; silver(I) carboxylate; solid-state structure; TGA; Introduction Focused electron

• [{AgO2CCH2OMe(PPh3)}n] is a suitable FEBID precursor for silver deposition. Thus, we discuss the synthesis and the chemical and physical properties of [{AgO2CCH2OMe}n] and [{AgO2CCH2OMe(PPh3)}n]. DFT (B3LYP) studies were applied to predict the most favorable fragmentation pathways according to the lowest energy

Inelastic electron tunneling spectroscopy of difurylethene-based photochromic single-molecule junctions

• Youngsang Kim,
• Safa G. Bahoosh,
• Dmytro Sysoiev,
• Thomas Huhn,
• Fabian Pauly and
• Elke Scheer

Beilstein J. Nanotechnol. 2017, 8, 2606–2614, doi:10.3762/bjnano.8.261

• functional theory (DFT) for charge transport through C5F-ThM molecular junctions. DFT, as implemented in the TURBOMOLE software package [26], was employed for the calculations using the exchange-correlation functional PBE [27][28][29][30] and the def-SV(P) [31][32] basis set, which is of split-valence

• the separation between the Au electrodes. Having determined the junction geometries, we computed the elastic transmission functions of the single-molecule junctions for the open and closed molecular forms, as shown in Figure 2b. Since it is known that DFT with semilocal exchange-correlation

• functionals, as used here, tends to underestimate the HOMO–LUMO gaps of molecules and does not capture nonlocal surface polarization effects that are essential for an accurate description of metal–molecule level alignments, we use here the so-called DFT+Σ method [34][35]. By adding a self-energy correction

Adsorption of iron tetraphenylporphyrin on (111) surfaces of coinage metals: a density functional theory study

• Hao Tang,
• Nathalie Tarrat,
• Véronique Langlais and
• Yongfeng Wang

Beilstein J. Nanotechnol. 2017, 8, 2484–2491, doi:10.3762/bjnano.8.248

• The adsorption of the iron tetraphenylporphyrin (FeTPP) molecule in its deckchair conformation was investigated on Au(111), Ag(111) and Cu(111) surfaces by performing spin-polarized density functional theory (DFT) calculations taking into account both van der Waals (vdW) interaction and on-site

• junction, the line shape of zero-bias resonance of the adsorbed FeTPP molecule reversibly varies by adjusting the tip to surface distance, i.e., by mechanically squeezing the molecule. Density functional theory (DFT) calculations reveal that the spin state of the Fe centre undergoes a switch from S = 2 to

• shifts explain the direction of the charge transfer. In summary, by performing spin-polarized DFT and NEB calculations, we have identified two stable magnetic states of the free FeTPP molecule in its deckchair conformation (C2h). The two states (HS and IS) were separated by an activation barrier of 0.07

The interplay between spin densities and magnetic superexchange interactions: case studies of mono- and trinuclear bis(oxamato)-type complexes

• Azar Aliabadi,
• Bernd Büchner,
• Vladislav Kataev and
• Tobias Rüffer

Beilstein J. Nanotechnol. 2017, 8, 2245–2256, doi:10.3762/bjnano.8.224

• of experimentally determined spin density distributions via the approaches by Maki and McGarvey [48] and Morton and Preston [49] according to the above described procedure are summarized in Figure 7. Furthermore and for comparison, DFT-calculated values of 2, 4, 6, 8 and 10 are given as well. One can

• and discussed together with the DFT results and to be critically evaluated with respect to geometrical features of the studied molecular complexes. In particular, the approach of Maki and McGarvey [48] implies a square planar geometry of the molecule, a condition that is not always fulfilled. A

Au₅₅, a stable glassy cluster: results of ab initio calculations

• Dieter Vollath,
• David Holec and
• Franz Dieter Fischer

Beilstein J. Nanotechnol. 2017, 8, 2221–2229, doi:10.3762/bjnano.8.222

• on the structure of the Au55 nanocluster highlights the necessity to look again at this problem using up-to-date theoretical methods. Therefore, quantum-mechanical calculations within the density functional theory (DFT) framework as implemented in the Vienna ab initio simulation package (VASP) [24

• bulk n·εbulk. This approach was introduced by Medasani et al. [30] to calculate the surface energy of silver clusters using DFT calculations. In their study, the surface energy γ was defined as The quantity a represents the surface area of the cluster. At the first view, this approach seems logical and

Comprehensive investigation of the electronic excitation of W(CO)₆ by photoabsorption and theoretical analysis in the energy region from 3.9 to 10.8 eV

• Mónica Mendes,
• Khrystyna Regeta,
• Filipe Ferreira da Silva,
• Nykola C. Jones,
• Søren Vrønning Hoffmann,
• Gustavo García,
• Chantal Daniel and
• Paulo Limão-Vieira

Beilstein J. Nanotechnol. 2017, 8, 2208–2218, doi:10.3762/bjnano.8.220

• of relevance to estimate neutral dissociation cross sections of W(CO)6, a precursor molecule in focused electron beam induced deposition (FEBID) processes, from electron scattering measurements. Keywords: cross sections; density functional theory (DFT) calculations; focused electron beam induced

• -dependent density functional theory (TDDFT) calculations [15], and electron momentum spectroscopy calculations [16] have been carried out. Other relevant studies include DFT calculations on the structure of W(CO)6 and its behaviour in infrared spectroscopy [17], as well as Raman [18] and infrared [18][19

• functional theory (DFT) level with B3LYP functional [35] with all electron and triple-ζ polarized basis sets in vacuum [36], leading to W–C and C–O bond lengths of 2.069 Å and 1.144 Å (1.141 Å from [15]), respectively. The metal bond length is slightly overestimated with respect to previous results yielding

Ester formation at the liquid–solid interface

• Nguyen T. N. Ha,
• Thiruvancheril G. Gopakumar,
• Nguyen D. C. Yen,
• Carola Mende,
• Lars Smykalla,
• Maik Schlesinger,
• Roy Buschbeck,
• Tobias Rüffer,
• Heinrich Lang,
• Michael Mehring and
• Michael Hietschold

Beilstein J. Nanotechnol. 2017, 8, 2139–2150, doi:10.3762/bjnano.8.213

• reaction path and energy barrier, a "nudged elastic band" calculation was done using DFT with the program code GPAW [37]. The molecule was placed in a large box with non-periodic boundary conditions and 7 Å of vacuum in each direction. The starting and end geometry (reactants and products) are first

• temperature for 10 min and then the substrate was cooled down to room temperature for STM imaging. DFT calculations were carried out using the grid-based projector augmented wave method (GPAW) [37]. The PBE exchange-correlation functional [38] and the LCAO mode [37] with the standard double-zeta-polarized

• should be almost parallel to the A axis. Energy diagram of the reaction path of TMA and undecanol to form TMA–undecyl ester and water for isolated molecules (gas phase) calculated using DFT (PBE). The corresponding geometry of the molecules in the simulation is shown for each energy point marked in the

Electronic structure, transport, and collective effects in molecular layered systems

• Torsten Hahn,
• Tim Ludwig,
• Carsten Timm and
• Jens Kortus

Beilstein J. Nanotechnol. 2017, 8, 2094–2105, doi:10.3762/bjnano.8.209

• phthalocyanine (F16CoPc/MnPc) heterostructure, are investigated by means of density functional theory (DFT) and the non-equilibrium Green’s function (NEGF) approach. Furthermore, a master-equation-based approach is used to include electronic correlations beyond the mean-field-type approximation of DFT. We

• describe the essential theoretical tools to obtain the parameters needed for the master equation from DFT results. Finally, an interacting molecular monolayer is considered within a master-equation approach. Keywords: electron correlation; electronic structure; quantum transport; spin transport

• molecule but also between neighboring molecules in a film [15], where they can lead to ordering phenomena. Our paper is organised as follows. First we will present the methodical background and results of our theoretical investigations on different phthalocyanine heterostructures by using the DFT-NEGF

Adsorbate-driven cooling of carbene-based molecular junctions

• Giuseppe Foti and
• Héctor Vázquez

Beilstein J. Nanotechnol. 2017, 8, 2060–2068, doi:10.3762/bjnano.8.206

• a first-principles, self-consistent description of the junction out of equilibrium based on density functional theory (DFT) and non-equilibrium Green’s functions (NEGF). We show how the change in the electronic structure of the junction induced by the presence of the adsorbate promotes the cooling

• cooling dynamics of a NHC-based molecular junction. We calculated the bias-dependent rates of emission and absorption of molecular vibrations using first principles methods based on DFT-NEGF. We considered an electron-withdrawing NH2 species adsorbed in the vicinity of the molecule on one of the

Intercalation of Si between MoS₂ layers

• Rik van Bremen,
• Qirong Yao,
• Soumya Banerjee,
• Deniz Cakir,
• Nuri Oncel and
• Harold J. W. Zandvliet

Beilstein J. Nanotechnol. 2017, 8, 1952–1960, doi:10.3762/bjnano.8.196

• DFT as implemented in the Vienna ab initio simulation package (VASP) [37]. The exchange–correlation interactions are treated using the generalized gradient approximation (GGA) within the Perdew–Burke–Ernzerhof (PBE) formulation [38]. The plane waves are expanded with an energy cut of 400 eV. Since the

• found a similar height variation using density functional theory (DFT) calculations of the intercalation of a single silicon layer in between two MoS2 layers. These calculations are discussed after the presentation of the experimental results. It is immediately obvious from Figure 1f that the transition

Coexistence of strongly buckled germanene phases on Al(111)

• Weimin Wang and
• Roger I. G. Uhrberg

Beilstein J. Nanotechnol. 2017, 8, 1946–1951, doi:10.3762/bjnano.8.195

• model. Keywords: core-level spectroscopy; DFT; germanene; STM; Introduction The properties of two-dimensional (2D) materials are currently subjected to intense experimental and theoretical studies. The research is focused on many important properties predicted by theory for various conceivable 2D

• images show hexagonal patterns in contrast to the honeycomb pattern reported in [13]. Our experimental data in combination with DFT calculations lead to a new model that can explain the experimental observations in terms of buckled germanene. Results and Discussion Figure 1a shows a LEED pattern, which

• -ordered hexagonal structures with (3×3) and (√7×√7) periodicities with respect to Al (1×1). Our DFT calculations show that the Ge layer relaxes to a hexagonal structure when two Ge atoms are positioned above threefold hollow sites on Al(111). The experimental and theoretical findings are consistent with a

Structural model of silicene-like nanoribbons on a Pb-reconstructed Si(111) surface

• Agnieszka Stępniak-Dybala and
• Mariusz Krawiec

Beilstein J. Nanotechnol. 2017, 8, 1836–1843, doi:10.3762/bjnano.8.185

• , and suppress the nanoribbon–substrate interaction. The proposed structural model reproduces well all the experimental findings. Keywords: density functional theory (DFT); scanning tunneling microscopy (STM); silicene; Si nanoribbons; Introduction The discovery of the exotic nature of graphene [1][2

• into the physics and chemistry of silicene/substrate systems density functional theory (DFT) calculations have usually been required. In all these cases silicene was reported to be formed in 2D domains with a corrugated hexagonal structure. Nevertheless, not all experiments, most notably on Ag(111

• ), support the scenario of silicene formation, mainly due to a problem with electronic properties. Therefore there is still a significant amount of skepticism about this issue. In many cases density functional theory (DFT) calculations were required to get more detailed information on what structures have

α-Silicene as oxidation-resistant ultra-thin coating material

• Ali Kandemir,
• Fadil Iyikanat,
• Cihan Bacaksiz and
• Hasan Sahin

Beilstein J. Nanotechnol. 2017, 8, 1808–1814, doi:10.3762/bjnano.8.182

• , Izmir, Turkey ICTP-ECAR Eurasian Center for Advanced Research, Izmir Institute of Technology, 35430, Izmir, Turkey 10.3762/bjnano.8.182 Abstract By performing density functional theory (DFT)-based calculations, the performance of α-silicene as oxidation-resistant coating on Ag(111) surface is

• ]. Kirkland et al. investigated the electrochemical response of graphene-coated metal surfaces and found that graphene causes reduction in the corrosion rate [8]. In addition, Topsakal et al. showed that graphene is a suitable coating material to protect surfaces from oxidation by performing DFT-based

Non-intuitive clustering of 9,10-phenanthrenequinone on Au(111)

• Ryan D. Brown,
• Rebecca C. Quardokus,
• Natalie A. Wasio,
• Jacob P. Petersen,
• Angela M. Silski,
• Steven A. Corcelli and
• S. Alex Kandel

Beilstein J. Nanotechnol. 2017, 8, 1801–1807, doi:10.3762/bjnano.8.181

• noted, and used a mechanically-cut Pt/Ir tip. All calculations were performed using the Q-Chem software package. Structures were optimized with density functional theory (DFT) utilizing the B3LYP functional [38][39]. The 6-311++G(3df,3pd) basis set was employed with a Lebedev quadrature containing 100

Adsorption and diffusion characteristics of lithium on hydrogenated α- and β-silicene

• Fadil Iyikanat,
• Ali Kandemir,
• Cihan Bacaksiz and
• Hasan Sahin

Beilstein J. Nanotechnol. 2017, 8, 1742–1748, doi:10.3762/bjnano.8.175

• Li are presented in the section “Results and Discussion”. Lastly, we conclude our results in section “Conclusion”. Results and Discussion Computational methodology The present calculations were performed using density functional theory (DFT) and the projector-augmented wave (PAW) method, as

• calculations. The van der Waals (vdW) correction to the GGA functional was included by using the DFT-D2 method of Grimme [50]. To properly simulate the structures, a 3×3-reconstructed hydrogenated silicene phase was placed on top of a 4×4 supercell of a two-layer Ag(111) surface. A 3×3×1 Γ-centered k-point

Transport characteristics of a silicene nanoribbon on Ag(110)

• Ryoichi Hiraoka,
• Chun-Liang Lin,
• Kotaro Nakamura,
• Ryo Nagao,
• Maki Kawai,
• Ryuichi Arafune and
• Noriaki Takagi

Beilstein J. Nanotechnol. 2017, 8, 1699–1704, doi:10.3762/bjnano.8.170

• of ≈1.5 nm width with the zigzag edges. Very recently, pentagonal chain models were proposed for SiNR on Ag(110) [27][28]. In this model, Si atoms constitute a five-membered ring to form a 1D chain. Density functional theory (DFT) calculations have demonstrated that freestanding honeycomb SiNR

• SiNR nanojunctions. Since the dI/dV spectrum essentially reflects the electronic density of states (DOS), we interpret the peak by comparing the dI/dV spectrum with the DOS spectra calculated for freestanding SiNR. The DFT studies have demonstrated that the geometric and electronic structures of SiNR

• H atoms, the honeycomb structure is unstable and vulnerable to the structural reconstruction at the edges. The DOS spectrum depends on the reconstructed structure. In the DFT study of Cahangirov et al. [29], the edge undergoes a reconstruction in which two deformed 6-membered rings are alternatively

Effect of the fluorination technique on the surface-fluorination patterning of double-walled carbon nanotubes

• Lyubov G. Bulusheva,
• Yuliya V. Fedoseeva,
• Emmanuel Flahaut,
• Jérémy Rio,
• Christopher P. Ewels,
• Victor O. Koroteev,
• Gregory Van Lier,
• Denis V. Vyalikh and
• Alexander V. Okotrub

Beilstein J. Nanotechnol. 2017, 8, 1688–1698, doi:10.3762/bjnano.8.169

• ]. There is little known in the literature concerning the mechanism of BrF3 fluorination, so we performed a series of DFT calculations to clarify this point. Importantly, we find that a decomposition of BrF3 over pristine graphene to give BrF2 and surface-bound F is endothermic (+0.25 eV) with a reaction

• with the graphene surface was studied using the DFT code AIMPRO [57][58][59] by fitting the charge density to plane waves with an energy cutoff of 300 Ha. Relativistic pseudopotentials generated by Hartwigsen, Goedecker and Hutter [60] were used. Correspondingly, 38, 44, and 28 independent Gaussian

Charge transfer from and to manganese phthalocyanine: bulk materials and interfaces

• Florian Rückerl,
• Daniel Waas,
• Bernd Büchner,
• Martin Knupfer,
• Dietrich R. T. Zahn,
• Francisc Haidu,
• Torsten Hahn and
• Jens Kortus

Beilstein J. Nanotechnol. 2017, 8, 1601–1615, doi:10.3762/bjnano.8.160

• in the core-level region, and polarization-dependent studies have often been carried out to study the molecular orientation on substrates. In addition to our experiments we performed calculations within the density functional theory (DFT) framework. We used a recent version of the NRLMOL all-electron

• DFT code [51][52], which uses large Gaussian-orbital basis sets for the representation of the electronic wavefunctions [53]. Unless noted otherwise we used the PBE functional [54] within the general gradient approximation (GGA) was used for all calculations. We semi-empirically included dispersion

• correction according to the Grimme DFT-D3 method [55] in all of our calculations. KxMnPc: formation of stable phases with MnPc anions The formation of compounds with composition KxMnPc was achieved by evaporation of potassium from so-called K dispensers (SAES Getters, S.P.A, Italy) onto MnPc thin films under

Deposition of exchange-coupled dinickel complexes on gold substrates utilizing ambidentate mercapto-carboxylato ligands

• Martin Börner,
• Laura Blömer,
• Marcus Kischel,
• Peter Richter,
• Georgeta Salvan,
• Dietrich R. T. Zahn,
• Pablo F. Siles,
• Maria E. N. Fuentes,
• Carlos C. B. Bufon,
• Daniel Grimm,
• Oliver G. Schmidt,
• Daniel Breite,
• Bernd Abel and
• Berthold Kersting

Beilstein J. Nanotechnol. 2017, 8, 1375–1387, doi:10.3762/bjnano.8.139

• susceptibility measurements (for 7 and 8) and (broken symmetry) density functional theory (DFT) calculations. An S = 2 ground state is demonstrated by temperature-dependent susceptibility and magnetization measurements, achieved by ferromagnetic coupling between the spins of the Ni(II) ions in 7 (J = +22.3 cm−1

• carboxylato bridges within the N3Ni(μ-SR)2(μ1,3-O2CR)NiN3 core, we utilized a breakdown approach in which the carboxylate group was virtually removed to obtain the hypothetical [Ni2(L)]2+ dication, which was subjected to broken symmetry DFT density functional theory calculations. The details of these

• accessible voids) of ≈1000 Å3 attributed to MeCN or EtOH solvate molecules. Only the structure of the complex cation could be identified. Computational details DFT calculations were carried out utilizing density functional theory (DFT). Perdew, Burke and Ernzerhof’s PBE0 hybrid functional [69][70] and

Comprehensive Raman study of epitaxial silicene-related phases on Ag(111)

• Dmytro Solonenko,
• Ovidiu D. Gordan,
• Guy Le Lay,
• Dietrich R. T. Zahn and
• Patrick Vogt

Beilstein J. Nanotechnol. 2017, 8, 1357–1365, doi:10.3762/bjnano.8.137

• explicitly considered in the modeling of this structure and of its properties in DFT calculations. Proposed structural models that are entirely based on the ordered parts of this structure are genuinely bound to fail in the correct description of the “” structure. Discussion Based on the in situ Raman

3D continuum phonon model for group-IV 2D materials

• Morten Willatzen,
• Lok C. Lew Yan Voon,
• Appala Naidu Gandi and
• Udo Schwingenschlögl

Beilstein J. Nanotechnol. 2017, 8, 1345–1356, doi:10.3762/bjnano.8.136

• the long-wavelength modes to density-functional results is included. Keywords: graphene; molybdenum disulfide; phonon; silicene; two-dimensional materials; Introduction Phonon spectra in two-dimensional (2D) nanomaterials have almost exclusively been computed using density-functional theory (DFT

• ]. In addition to obtaining a spectrum, it is often also useful to be able to predict and/or interpret properties of the spectrum based upon either microscopic or symmetric arguments. An excellent example is the prediction of a Dirac cone for silicene on the basis of symmetry [7] when DFT calculations

• coordinate in the analysis to reveal the true phonon dispersions as observed experimentally and in DFT calculations. The general 3D elastic equations are given by the equation of motion [14] where Tik is the stress tensor, ρ is the mass density, and ui is the displacement. Equation 1 contains all the physics

Two-dimensional silicon and carbon monochalcogenides with the structure of phosphorene

• Dario Rocca,
• Ali Abboud,
• Ganapathy Vaitheeswaran and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2017, 8, 1338–1344, doi:10.3762/bjnano.8.135

• of 1.0 eV was found for the HSE gap, which does not significantly differ from the PBE estimate. As shown in Table 1 the DFT values we found are in good agreement with the results in the literature [35][39]. As previously noted [39], the top of the valence band is slightly shifted from Γ and

Hierarchically structured nanoporous carbon tubes for high pressure carbon dioxide adsorption

• Julia Patzsch,
• Deepu J. Babu and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2017, 8, 1135–1144, doi:10.3762/bjnano.8.115

• linearized isotherm equation between P/P0 0.035 and 0.2 and the pore size was calculated by density functional theory (DFT) for slit pores. The scanning electron microscopy (SEM) micrographs were obtained using a Philips XL 30 FEG (20 kV) instrument equipped with an EDX (energy dispersive X-ray) detector

• isotherm of carbon tubes (4) (Figure 6a) resembles a type-IVa isotherm [45], however, with a high microporous content. These micropores are responsible for the observed steep increase in the adsorption at very low relative pressure (Figure 6b). The pore width distribution calculated by the DFT method

• (DFT, slit pore model) for carbon tubes (4) which are carbonized at 950 °C (black/triangles), 1300 °C (red/diamonds) and 1600 °C (blue/circles). TEM images of a SiC tube wall with interconnected, crystalline SiC particles (a) and the corresponding SAED pattern (b). Individual SiC crystallites are shown