Spontaneous shape transition of Mn_xGe_1−x islands to long nanowires

• S. Javad Rezvani,
• Luc Favre,
• Gabriele Giuli,
• Yiming Wubulikasimu,
• Isabelle Berbezier,
• Augusto Marcelli,
• Luca Boarino and
• Nicola Pinto

Beilstein J. Nanotechnol. 2021, 12, 366–374, doi:10.3762/bjnano.12.30

• spontaneous shape transition, from regular islands to elongated nanowires, upon high-temperature annealing of a thin Mn wetting layer evaporated on Ge(111). We demonstrate that 4.5 monolayers is the critical thickness of the Mn layer, governing the shape transition to wires. A small change around this value

• tend to ≃80 nm of width. We found that tuning the annealing process allows one to extend the wire length up to ≃1.5 μm with a minor rise of the lateral size to ≃100 nm. The elongation process of the nanostructures is in agreement with a strain-driven shape transition mechanism proposed in the

• formation of quantum wires [35]. In this method, wires are obtained via epitaxial growth of a strained wetting layer followed by annealing at high temperature. However, only few studies have been dedicated to strain-induced elongation mechanisms leading to the formation of semiconducting nanowires, such as

Differences in surface chemistry of iron oxide nanoparticles result in different routes of internalization

• Barbora Svitkova,
• Vlasta Zavisova,
• Veronika Nemethova,
• Martina Koneracka,
• Miroslava Kretova,
• Filip Razga,
• Monika Ursinyova and
• Alena Gabelova

Beilstein J. Nanotechnol. 2021, 12, 270–281, doi:10.3762/bjnano.12.22

• primer (5′-CTAAGCAGTTGGTGGTGCAG-3′), on a CFX96TM Real-Time PCR Detection System cycler (Bio-Rad). Specifically, samples were denatured at 95 °C for 10 min, and the quantification program had 40 repeats (30 s annealing at 60 °C, 30s amplification at 72 °C). GAPDH was used as a “housekeeping” gene for the

Extended iron phthalocyanine islands self-assembled on a Ge(001):H surface

• Rafal Zuzak,
• Marek Szymonski and
• Szymon Godlewski

Beilstein J. Nanotechnol. 2021, 12, 232–241, doi:10.3762/bjnano.12.19

• annealing. Here, we obtain islands composed of upright-standing molecules already at room temperature, which indicates a dominant role of intermolecular forces compared to interactions between molecules and hydrogenated surface. In order to analyze in more detail the properties of the FePc islands, we

TiO_x/Pt₃Ti(111) surface-directed formation of electronically responsive supramolecular assemblies of tungsten oxide clusters

• Marco Moors,
• Yun An,
• Agnieszka Kuc and
• Kirill Yu. Monakhov

Beilstein J. Nanotechnol. 2021, 12, 203–212, doi:10.3762/bjnano.12.16

• , respectively. After the annealing at 600 K, hardly any single nanocluster can be found on the surface. In return, the step edges are now highly decorated with clusters, while the terraces are covered by up to 1 nm high and 5 nm wide cluster agglomerations. This indicates a high lateral mobility of the clusters

• at elevated temperatures, which allows for an energy contact by agglomeration due to strong intermolecular interactions. After annealing the sample at 900 K, the formation of larger islands is observed. The thickness of these islands is always approx. 0.6 nm, which indicates the formation of a WO3

• structures with a low influence of molecular electronic features. Thus, annealing a surface covered with W3O9 may also be used as a gentle way to grow well-defined WO3 islands or thin films. In that context, the observed thickness limitation of two WO3 unit cells could be of special interest since the height

Direct observation of the Si(110)-(16×2) surface reconstruction by atomic force microscopy

• Tatsuya Yamamoto,
• Ryo Izumi,
• Kazushi Miki,
• Takahiro Yamasaki,
• Yasuhiro Sugawara and
• Yan Jun Li

Beilstein J. Nanotechnol. 2020, 11, 1750–1756, doi:10.3762/bjnano.11.157

• reliable production of nanowires and other nanostructures [7][10][11][12][13]. By annealing below 700 °C [14], the Si(110)-(16×2) reconstruction is formed over large areas on the Si(110) surface. It has been widely investigated by reflection high-energy electron diffraction (RHEED) analysis [14][15

• 1200 °C for 3 s and annealing at 650 °C for 30 min. The sample was heated by flowing an electric current in the direction; thereby, a single-domain surface can be easily formed on the Si(110) surface [10]. Results and Discussion Figure 1 shows a typical AFM image of a Si(110) surface. The

The influence of an interfacial hBN layer on the fluorescence of an organic molecule

• Christine Brülke,
• Oliver Bauer and
• Moritz M. Sokolowski

Beilstein J. Nanotechnol. 2020, 11, 1663–1684, doi:10.3762/bjnano.11.149

• of borazine that is known to occur even when stored at low temperatures, m/z 2) and borazine (m/z 80) showed a ratio of approximately 1:1. The clean Cu(111) surface was prepared by consecutive steps of sputtering for 30 min with Ar+ ions (1000 eV, 4 μA) and annealing at 1010 K for 30 min. After the

• ) surface, the hBN layers, and the PTCDA layers was checked by LEED. We used a SPA-LEED instrument as described in [30]. An additional annealing step between the last sputter cycle and the borazine deposition was omitted here in order to prevent segregation of chemical impurities from the Cu bulk to the

• minute. During deposition, the sample was held at a constant temperature. PTCDA layers on Cu(111) were prepared by keeping the sample at a temperature of either 20 or 300 K during deposition. PTCDA layers on hBN/Cu(111) were prepared by deposition at a sample temperature of 20 K and subsequent annealing

Amorphized length and variability in phase-change memory line cells

• Nafisa Noor,
• Sadid Muneer,
• Raihan Sayeed Khan,
• Anna Gorbenko and
• Helena Silva

Beilstein J. Nanotechnol. 2020, 11, 1644–1654, doi:10.3762/bjnano.11.147

• approx. 1 mTorr at a temperature of 675 K for 10 min to reach the crystalline phase (annealing profile shown in Figure 2a). The electrical measurements were performed at room temperature. Electrical pulses, generated by an arbitrary function generator (Tektronix AFG 3102), were applied to the cells; a

• profile used for annealing the as-fabricated amorphous devices to the crystalline phase, with a constant temperature of 675 K for the last 10 min. Inset shows the SEM image of an untested annealed GST line cell, with metal-to-metal LGST ≈ 470 nm, WGST ≈ 130 nm, and tGST ≈ 50 nm. (b) Electrical measurement

Adsorption and self-assembly of porphyrins on ultrathin CoO films on Ir(100)

• Feifei Xiang,
• Tobias Schmitt,
• Marco Raschmann and
• M. Alexander Schneider

Beilstein J. Nanotechnol. 2020, 11, 1516–1524, doi:10.3762/bjnano.11.134

• molecules were carefully outgassed for 2 to 5 h prior to deposition at ±10 K of the evaporation temperature. CoO was prepared on an Ir(100) single crystal surface cleaned by ion sputtering and annealing. The Ir(100)-(1 × 1) surface was prepared according to [31]. We employ thin films of two distinct

• ) at 320 K substrate temperature followed by annealing in 2 × 10−9 mbar O2 at 520 K. To improve ordering, the films were flash-heated to 670 K in UHV. The cleanliness, quality and thickness of the prepared substrates was verified by comparison to low-energy electron diffraction intensity data of

• keeping the substrate at that temperature during deposition or by short time (5 min) annealing. Either choice of thermal treatment resulted in the same molecular structures. Higher temperatures could not be applied to 2 without changing the appearance of the molecules. This is attributed to metalation of

Controlling the electronic and physical coupling on dielectric thin films

• Philipp Hurdax,
• Michael Hollerer,
• Larissa Egger,
• Georg Koller,
• Xiaosheng Yang,
• Anja Haags,
• Serguei Soubatch,
• Frank Stefan Tautz,
• Mathias Richter,
• Alexander Gottwald,
• Peter Puschnig,
• Martin Sterrer and
• Michael G. Ramsey

Beilstein J. Nanotechnol. 2020, 11, 1492–1503, doi:10.3762/bjnano.11.132

• (100) crystal was cleaned by cycles of Ar+ sputtering and annealing at 500 °C. MgO(100) films were grown by Mg evaporation in an oxygen environment. The Mg fluxes used were on the order of 1 Å/min as monitored by a quartz microbalance. The MgO deposition was done at a temperature of 270 °C and at an O2

• thickness of 2.105 Å. Work functions, measured from the secondary electron cutoff in the photoemission, could be reduced by annealing in UHV or further Mg exposure while annealing. The work function could be increased by O2 exposure (5 × 10−7–2 × 10−4 mbar) at moderate temperatures. Monitoring the work

Self-assembly and spectroscopic fingerprints of photoactive pyrenyl tectons on hBN/Cu(111)

• Domenik M. Zimmermann,
• Knud Seufert,
• Luka Ðorđević,
• Tobias Hoh,
• Sushobhan Joshi,
• Tomas Marangoni,
• Davide Bonifazi and
• Willi Auwärter

Beilstein J. Nanotechnol. 2020, 11, 1470–1483, doi:10.3762/bjnano.11.130

• was cleaned by repeated Ar+ sputtering cycles at an energy of 800–1000 eV, followed by annealing at 1070 K. Monolayer hBN was grown via chemical vapor deposition using borazine ((HBNH)3, Katchem spol s.r.o, www.katchem.cz), following a protocol described previously [25]. Subsequently, a submonolayer

Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir

• Mathias Franz,
• Romy Junghans,
• Paul Schmitt,
• Adriana Szeghalmi and
• Stefan E. Schulz

Beilstein J. Nanotechnol. 2020, 11, 1439–1449, doi:10.3762/bjnano.11.128

• discussed in detail. Particle formation The surface of the deposited noble metal films has been analysed before and after the thermal annealing using a scanning electron microscope (SEM). The generated particles have been analysed using “ImageJ” [24] with the package collection “Fiji” [25]. For the analysis

• nanometre scale. The target film thickness was 5 nm and was adjusted using the sputtering rate. Figure 1 shows SEM images after the annealing process (Figure 1a–d) and the results of the particle distribution analysis (Figure 1f–j). Figure 1e shows the surface of the Ir sample directly after the ALD process

• , we were able to cover the whole wafer surface homogeneously with nanoparticles. The particle size distribution can easily be modified by varying film thickness and annealing conditions or, correspondingly, the number of ALD cycles for the Ir particles. Silicon etching The wafers with noble metal

Impact of fluorination on interface energetics and growth of pentacene on Ag(111)

• Qi Wang,
• Meng-Ting Chen,
• Antoni Franco-Cañellas,
• Bin Shen,
• Thomas Geiger,
• Holger F. Bettinger,
• Frank Schreiber,
• Ingo Salzmann,
• Alexander Gerlach and
• Steffen Duhm

Beilstein J. Nanotechnol. 2020, 11, 1361–1370, doi:10.3762/bjnano.11.120

• [60] and vacuum-sublimed on clean metal surfaces (prepared by repeated Ar+ ion sputtering and annealing cycles [up to 550 °C]), with deposition rates of about 0.5 Å/min. The film mass thickness was monitored with a quartz crystal microbalance (QCM) near the sample, and a nominal thickness of 4 Å is

Atomic defect classification of the H–Si(100) surface through multi-mode scanning probe microscopy

• Jeremiah Croshaw,
• Thomas Dienel,
• Taleana Huff and
• Robert Wolkow

Beilstein J. Nanotechnol. 2020, 11, 1346–1360, doi:10.3762/bjnano.11.119

• concentration of dihydrides can be controlled by lowering the annealing temperature during sample preparation [19][70]. While the two varieties of dihydride look unique overall in STM empty states topography (Figure 2d-1 and Figure 2e-1), the side of the pair that the dihydride unit(s) appear on consistently

• ” (Figure 2h-6). A defect of similar appearance was reported in a prior work exploring chlorine-terminated silicon [80] which was linked to water contamination in the vacuum chamber (observed as H and OH bonded to the unterminated surface [15][16][17]). A mild annealing followed by halogen-termination

• (100). Samples were degassed at 600 °C overnight followed by multiple cycles of flash annealing at 1250 °C. The samples were then terminated with hydrogen by exposing them to molecular hydrogen (10−6 Torr) while the Si sample was held at 330 °C for 2 min. The molecular hydrogen was cracked from H2 gas

Growth of a self-assembled monolayer decoupled from the substrate: nucleation on-command using buffer layers

• Robby Reynaerts,
• Kunal S. Mali and
• Steven De Feyter

Beilstein J. Nanotechnol. 2020, 11, 1291–1302, doi:10.3762/bjnano.11.113

• nm by carrying out systematic concentration-dependent measurements since lower solution concentrations are known to favor large domain sizes. Annealing of the samples was also carried out. We noticed that at lower solution concentrations, the n-C50 monolayers exhibit a highly dynamic behavior with

Hybridization vs decoupling: influence of an h-BN interlayer on the physical properties of a lander-type molecule on Ni(111)

• Maximilian Schaal,
• Takumi Aihara,
• Marco Gruenewald,
• Felix Otto,
• Jari Domke,
• Roman Forker,
• Hiroyuki Yoshida and
• Torsten Fritz

Beilstein J. Nanotechnol. 2020, 11, 1168–1177, doi:10.3762/bjnano.11.101

• LEED pattern due to a post-growth annealing process in a temperature range from 100 °C to 300 °C was not visible. In fact, at a temperature of 300 °C the desorption of DBP molecules was observed by a decrease of the C 1s intensity measured by XPS (not shown). Therefore, we conclude that a post-growth

• annealing process does not lead to an increase of the lateral order. However, a highly ordered film was achieved by depositing at a substrate temperature of 170 °C. The LEED image in Figure 3a shows the corresponding diffraction pattern induced by a highly ordered molecular film. For this reason, we labeled

• Ar+ sputtering at room temperature and annealing at 800 °C. The h-BN layer was grown by thermal dehydrogenation of borazine molecules at a substrate temperature of 800 °C similar to [19]. We purchased borazine from Katchem Ltd. (Czech Republic) with a specified purity of >98%. The quality of the h-BN

Scanning tunneling microscopy and spectroscopy of rubrene on clean and graphene-covered metal surfaces

• Karl Rothe,
• Alexander Mehler,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2020, 11, 1157–1167, doi:10.3762/bjnano.11.100

• surface. Experimental The experiments were performed with an STM operated in ultrahigh vacuum (10−9 Pa) and at low temperature (Pt(111) and graphene-covered Pt(111) at 5 K, Au(111) at 78 K). Pt(111) and Au(111) surfaces were cleaned by Ar+ ion bombardment and annealing. Graphene was epitaxially grown on

• backbones were presented in [25][26][27][34] for Au(111) and in [35] for Bi(111). In these reports, the deposition of molecules was performed at 5 K [25][26][27][34] and 100 K [35] with subsequent annealing at room temperature [25][26][27][34] and 350 K [35]. Therefore, deposition at low temperature seems

• to favor the adsorption with twisted and tilted backbones, possibly due to an initial high density of small island with chiral molecules, while the subsequent annealing preserves the twisted and tilted configuration of the molecular backbone and leads to homochiral domains. The twisted configuration

Monolayers of MoS₂ on Ag(111) as decoupling layers for organic molecules: resolution of electronic and vibronic states of TCNQ

• Asieh Yousofnejad,
• Gaël Reecht,
• Nils Krane,
• Christian Lotze and
• Katharina J. Franke

Beilstein J. Nanotechnol. 2020, 11, 1062–1071, doi:10.3762/bjnano.11.91

• vibronic states of the gas-phase molecule. Results and Discussion We have grown monolayer islands of MoS2 on an atomically clean Ag(111) surface, which had been exposed to sputtering–annealing cycles under ultrahigh vacuum before. The growth procedure was adapted from that of MoS2 on Au(111) [34][35], with

Highly sensitive detection of estradiol by a SERS sensor based on TiO₂ covered with gold nanoparticles

• Andrea Brognara,
• Ili F. Mohamad Ali Nasri,
• Beatrice R. Bricchi,
• Andrea Li Bassi,
• Caroline Gauchotte-Lindsay,
• Matteo Ghidelli and
• Nathalie Lidgi-Guigui

Beilstein J. Nanotechnol. 2020, 11, 1026–1035, doi:10.3762/bjnano.11.87

• . Specifically, we demonstrate that the TiO2 background pressure during pulsed laser deposition and the annealing conditions offer control over the formation of Au nanoparticles with different sizes, shapes and distributions, yielding a versatile sensor. We have exploited the surface for the detection of 17β

• quartz microbalance sensor. Three different values of Au thickness, namely 3, 6, and 15 nm, were selected enabling the formation of different sizes of AuNPs through subsequent annealing. Selected samples underwent annealing at 500 °C for 2 h in air, in a Lenton muffle furnace with 4 °C/min heating ramp

• top of the TiO2 films. Three nominal thickness values of 3, 6, and 15 nm were chosen, in order to obtain NPs with different diameters (Table 1). After deposition of Au, samples underwent an annealing treatment in a furnace at 500 °C for 2 h, which leads to the crystallization of TiO2 to the anatase

Gas-sensing features of nanostructured tellurium thin films

• Dumitru Tsiulyanu

Beilstein J. Nanotechnol. 2020, 11, 1010–1018, doi:10.3762/bjnano.11.85

• both the heating and the annealing of the samples, the test cell was mounted inside a furnace. A platinum temperature detector (PT-100, Cliptec Kabeltechnik, Germany) was placed close to the film and was used to assist with the temperature control. The data was processed using a PC equipped with a data

Band tail state related photoluminescence and photoresponse of ZnMgO solid solution nanostructured films

• Vadim Morari,
• Aida Pantazi,
• Nicolai Curmei,
• Vitalie Postolache,
• Emil V. Rusu,
• Marius Enachescu,
• Ion M. Tiginyanu and
• Veaceslav V. Ursaki

Beilstein J. Nanotechnol. 2020, 11, 899–910, doi:10.3762/bjnano.11.75

• emission properties were studied by photoluminescence spectroscopy under excitation at 325 nm. It was found that annealing at 500 °C leads to the production of macroscopically homogeneous wurtzite phase films, while thermal treatment at higher or lower temperature results in the degradation of the

• deposited by spin coating and subjected to post-deposition annealing at 400 °C and 500 °C is similar. However, the morphology degrades for films annealed at temperatures higher than 600 °C. Figure 2 compares the surface morphology of films prepared by aerosol spray pyrolysis and spin coating annealed at 500

• . At the same time, the annealing of films at 650 °C (see Figure 2c) leads to deterioration of the morphology resulting in numerous cracks. We suppose that the difference in roughness of films prepared by the two methods is determined by the specific features of the technology. Namely, the deposition

Adsorption behavior of tin phthalocyanine onto the (110) face of rutile TiO₂

• Lukasz Bodek,
• Mads Engelund,
• Aleksandra Cebrat and
• Bartosz Such

Beilstein J. Nanotechnol. 2020, 11, 821–828, doi:10.3762/bjnano.11.67

• molecules into the Sn-down conformation was observed either after sample annealing at 200 °C or as a result of tip-induced manipulation. Room-temperature measurements conducted for a coverage of close to a monolayer showed no tendency for molecular arrangement. Keywords: rutile (110) surface; scanning

• the position of a tin atom protruding from the macrocycle: “Sn-up” and “Sn-down”. Switching from the Sn-up to the Sn-down geometry can be realized by annealing the sample at 200 °C or by tip-induced manipulation (bias pulse). X-ray photoelectron spectroscopy (XPS) measurements reveal a lack of strong

• prepared by repetitive cycles of Ar+-ion bombardment at an energy of 1 keV and subsequent annealing to a temperature of 700 °C. Tin phthalocyanine molecules (Tokyo Chemical Industry Co., Ltd.) were thermally evaporated by using an effusion cell (Kentax GmbH). After prudent degassing, the deposition flux

Epitaxial growth and superconducting properties of thin-film PdFe/VN and VN/PdFe bilayers on MgO(001) substrates

• Wael M. Mohammed,
• Igor V. Yanilkin,
• Amir I. Gumarov,
• Airat G. Kiiamov,
• Roman V. Yusupov and
• Lenar R. Tagirov

Beilstein J. Nanotechnol. 2020, 11, 807–813, doi:10.3762/bjnano.11.65

• , Germany). LEED images were taken of the pristine MgO(001) substrate after annealing (Figure 1a), after the deposition of VN(30 nm) on MgO (Figure 1b), after the deposition of Pd0.92Fe0.08 on VN (Figure 1c) and after the deposition of VN on Pd0.96Fe0.04 (Figure 1d). Figure 1b indicates that the individual

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• brightest SPSs observed in any material at room temperature. Similarly, bulk BN was studied by [100] after annealing the sample in Ar at 850 °C for 30 min and at 0.5 Torr to increase the concentration of defects with similar ZPLs previously reported. However, they were found to photo-bleach with excitation

• density of emitters. Such methods based on high-temperature annealing in air and ultraviolet ozone processing are effectively used to improve SP purity (g(2)(0) ≤ 0.1) and the linewidth (FWHM room temperature of ≈3 nm) of the ZPL of CVD-grown h-BN [108]. By control of the boron diffusion through copper

• with 10 keV gallium ions at a dose of 10−14 C/µm2 with subsequent annealing with argon at 1 Torr and 750 °C for 30 min. The lifetime, brightness, and PL stability of this SPE are similar to those in 2D h-BN, however with a wavelength variation smaller by a factor of five as compared to the SPEs in 2D h

Structural optical and electrical properties of a transparent conductive ITO/Al–Ag/ITO multilayer contact

• Aliyu Kabiru Isiyaku,
• Ahmad Hadi Ali and
• Nafarizal Nayan

Beilstein J. Nanotechnol. 2020, 11, 695–702, doi:10.3762/bjnano.11.57

• pure ITO layer (as reference) were prepared by RF and DC sputtering. The microstructural, optical and electrical properties of the ITO/Al–Ag/ITO (IAAI) films were investigated before and after annealing at 400 °C. X-ray diffraction measurements show that the insertion of the Al–Ag intermediate bilayer

• led to the crystallization of an Ag interlayer even at the as-deposited stage. Peaks attributed to ITO(222), Ag(111) and Al(200) were observed after annealing, indicating an enhancement in crystallinity of the multilayer films. The annealed IAAI film exhibited a remarkable improvement in optical

• × 10−3 Ω−1). These highly conductive and transparent ITO films with Al–Ag interlayer can be a promising contact for low-resistance optoelectronics devices. Keywords: annealing; DC sputtering; figure of merit; indium tin oxide (ITO); multilayer structure; RF sputtering; Introduction Transparent

Soybean-derived blue photoluminescent carbon dots

• Shanshan Wang,
• Wei Sun,
• Dong-sheng Yang and
• Fuqian Yang

Beilstein J. Nanotechnol. 2020, 11, 606–619, doi:10.3762/bjnano.11.48

• residuals to synthesize carbon nanoparticles by hydrothermal carbonization (HTC), annealing at high temperature, and laser ablation (LA) in a NH4OH solution. The carbon nanoparticles synthesized with the HTC process (HTC-CDs) exhibit photoluminescent characteristics with strong blue emission. The annealing

• , which involves the HTC treatment, high-temperature annealing, and LAL processing, sequentially. The purpose of the LAL processing is to introduce N-containing functional groups onto the surface of carbon nanoparticles and to recover the PL of carbon nanoparticles/CDs that was quenched by the high

• -temperature annealing. Both methods can be categorized as top-down methods in contrast to bottom-up methods. The PL characteristics of the CDs produced by both methods are analyzed, and the PL mechanisms of the CDs are discussed. The strategies developed in this work offer simple and effective means for