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Search for "defects" in Full Text gives 731 result(s) in Beilstein Journal of Nanotechnology. Showing first 200.
In situ optical sub-wavelength thickness control of porous anodic aluminum oxide
Beilstein J. Nanotechnol. 2024, 15, 126–133, doi:10.3762/bjnano.15.12
- ] and optical sensors [4][5], require precise control of PAAO layer thickness in the optical sub-wavelength range. Among other examples, by tuning the thickness of PAAO between 200 and 600 nm, it becomes possible to selectively enhance or suppress photoluminescence (PL) bands originating from defects in
Berberine-loaded polylactic acid nanofiber scaffold as a drug delivery system: The relationship between chemical characteristics, drug-release behavior, and antibacterial efficiency
Beilstein J. Nanotechnol. 2024, 15, 71–82, doi:10.3762/bjnano.15.7
- treatment of bone defects [21]. In dentistry, anti-infective nanofiber-based drug-release systems have been investigated for periodontal disease control, endodontic therapy, cariogenic microorganism control, and tissue reconstruction [25]. Due to the controlled drug release, BBR-loaded nanofiber scaffolds
- exhibited excellent performance in repairing bone defects [3][26], healing diabetic foot ulcers [27], promoting hemostasis [28], acting as anti-leishmanial drugs [29], and inhibiting microbial agents [27][30]. Zhou et al. [31] developed hybrids of nanofibers and microparticles for dual-step controlled
unDrift: A versatile software for fast offline SPM image drift correction
Beilstein J. Nanotechnol. 2023, 14, 1225–1237, doi:10.3762/bjnano.14.101
- ]. Offline drift correction strategies, in contrast, correct the effect of drift in SPM images after the measurement. Drift correction has been carried out based on the apparent movement of stationary features (e.g., fixed defects or adsorbates) traceable in consecutive images [5][29][30][31] or images with
- surface features whose positions are actually constant, such as defects and step edges. This is illustrated in Figure 3, where the stationary surface features marked with colored crosses seem to move between Figure 3a and Figure 3b. Here, it is important to note that all stationary features “moved” by the
- optimized lattices as found by unDrift are shown as red lines. Only the centers of the autocorrelations are shown. (a, b) Two consecutive up images recorded with high-resolution AFM on calcite(10.4) in ultrahigh vacuum. The images show several defects, whose positions are marked with colored crosses in both
Spatial variations of conductivity of self-assembled monolayers of dodecanethiol on Au/mica and Au/Si substrates
Beilstein J. Nanotechnol. 2023, 14, 1169–1177, doi:10.3762/bjnano.14.97
- substrate and the mercury electrode yields the conductivity of the SAM, averaged over the contact area of the mercury droplet. In such studies, one of the crucial problems was mercury filling out defects in the SAMs, which leads to short circuits and unreliable currents running through the microcontact
Density functional theory study of Au-fcc/Ge and Au-hcp/Ge interfaces
Beilstein J. Nanotechnol. 2023, 14, 1093–1105, doi:10.3762/bjnano.14.90
- . Our DFT calculations for the Au-fcc(011)/Ge(001) junction show how the presence of defects in the interface layer can help to stabilize the atomic pattern, consistent with microscopic images. Although the Au-hcp/Ge interface is characterized by a similar interface energy, it reveals large atomic
- microscopy image [23] one can identify the Au-hcp plane parallel to Ge substrate as (010). We discuss the optimized structures and defects that could stabilize the interface. Finally, we demonstrate the electronic properties of Au/Ge junctions and the formation of Ge–Au bonds at the interface. The Appendices
- variant by introducing defects into the interface layer. We investigated three supercells of variant D, in which some pairs of Au atoms in the interface layer were replaced by Ge atoms. Their optimized atomic arrangements are presented in Figure 7b–d. We can observe that while one such defect, shown in
Experimental investigation of usage of POE lubricants with Al2O3, graphene or CNT nanoparticles in a refrigeration compressor
Beilstein J. Nanotechnol. 2023, 14, 1041–1058, doi:10.3762/bjnano.14.86
- /(m·K) [39], respectively. On the other hand, graphene has a thermal conductivity coefficient ranging from 4840 to 5300 W/(m·K) [39]. These data on thermal conductivity coefficients are applicable to pristine materials. However, impurities and defects of the materials strongly impact their heat
- transport behaviour. The characterisation of the materials discussed in the Methodology section did not reveal any obvious impurities or defects. Nevertheless, enriching the characterisation of the graphene nanoplatelets may facilitate the understanding of the dominant effect of graphene on compressor power
A visible-light photodetector based on heterojunctions between CuO nanoparticles and ZnO nanorods
Beilstein J. Nanotechnol. 2023, 14, 1018–1027, doi:10.3762/bjnano.14.84
- , these methods still face problems, including the requirements of controlling defects, scale-up for mass production, or troubles relating to decoration uniformity [31][32]. Another method is to form heterojunctions of ZnO and other narrow-bandgap semiconductors (NiO [33], PbS [34], CdS [35], and MoS2[36
Exploring internal structures and properties of terpolymer fibers via real-space characterizations
Beilstein J. Nanotechnol. 2023, 14, 1004–1017, doi:10.3762/bjnano.14.83
- scans (Figure 5a,b) show that elevated fibrils exhibit high transverse stiffness. This high stiffness suggests that the material within Technora® fibrils is well-ordered, that is, lacking compliant nanoscale subdomains that may arise from voids, mismatched molecules, or other defects. Furthermore, line
Two-dimensional molecular networks at the solid/liquid interface and the role of alkyl chains in their building blocks
Beilstein J. Nanotechnol. 2023, 14, 872–892, doi:10.3762/bjnano.14.72
- domains with fewer defects than NDI-Cn (Figure 15a–d). Such large-area ordering due to the interdigitated structure was attributed to the larger dispersion interactions of the unsaturated chains compared to that of the fully saturated ones. The stabilizing effect of unsaturated alkyl chains has been also
Ultralow-energy amorphization of contaminated silicon samples investigated by molecular dynamics
Beilstein J. Nanotechnol. 2023, 14, 834–849, doi:10.3762/bjnano.14.68
- . The 500 subsequent bombardments with their collision cascades lead to the displacement of target atoms, creating disorder and point defects. Hydrogen and oxygen atoms get mixed into the target and can get trapped at interstitial or vacancy sites. The different kind of defects are not intrinsically
Nanostructured lipid carriers containing benznidazole: physicochemical, biopharmaceutical and cellular in vitro studies
Beilstein J. Nanotechnol. 2023, 14, 804–818, doi:10.3762/bjnano.14.66
- and NLC-BNZ, respectively, using the Scherrer approximation. However, a broadening of the lower part of the main peak in the NLC-BNZ samples suggests defects in the structure, probably due to the inclusion of BNZ in the formulation. At smaller angles, the copolymer on the surface exhibited a lamellar
Silver-based SERS substrates fabricated using a 3D printed microfluidic device
Beilstein J. Nanotechnol. 2023, 14, 793–803, doi:10.3762/bjnano.14.65
- manufacturer is 100 µm × 100 µm, a mold with line features was created instead of printing the microfluidic device directly. To minimize defects during the printing of the mold, the microchannel was designed with larger dimensions. Three inlets for the mixing channel were made with a width and a depth of 200
Carboxylic acids and light interact to affect nanoceria stability and dissolution in acidic aqueous environments
Beilstein J. Nanotechnol. 2023, 14, 762–780, doi:10.3762/bjnano.14.63
- biological systems. Ceria has been considered a possible UV filter in sunscreens [2][42]. Oxygen defects in the crystal lattice of ceria can presumably be altered by UV irradiation causing a redox switching of the cerium atoms between Ce3+ and Ce4+. This could explain the observance of a blue shift of the
Control of morphology and crystallinity of CNTs in flame synthesis with one-dimensional reaction zone
Beilstein J. Nanotechnol. 2023, 14, 741–750, doi:10.3762/bjnano.14.61
- defects and disorders of the sp2-hybridized sidewalls, while the G′ peak at 2500–2900 cm−1 represents photon–phonon interactions [27]. The absence of a low-frequency peak below 200 cm−1, usually assigned to the A1g symmetry radial breathing mode, which is the main characteristic of SWCNTs [28], indicates
Cross-sectional Kelvin probe force microscopy on III–V epitaxial multilayer stacks: challenges and perspectives
Beilstein J. Nanotechnol. 2023, 14, 725–737, doi:10.3762/bjnano.14.59
- charge regions and, thus, the presence of several junctions along the stack. Furthermore, a contrast enhancement in the surface potential image was observed when KPFM was performed under illumination, which is analysed in terms of the reduction of surface band bending induced by surface defects by
- interpretation of the KPFM data, specifically to investigate the effect of space charge regions, surface defects, and illumination on VCPD [13]. Experimental Sample preparation The structure of the studied sample is summarized in Table 1. This multilayer stack structure was epitaxially grown using a MOVPE
- section was used. KPFM is a surface technique; therefore, KPFM measurements are strongly influenced by the presence of surface defects. In order to provide a quantitative analysis of the experimental results, KELSCAN allows for the introduction of defects in a surface layer of arbitrary depth. The model
A graphene quantum dots–glassy carbon electrode-based electrochemical sensor for monitoring malathion
Beilstein J. Nanotechnol. 2023, 14, 701–710, doi:10.3762/bjnano.14.56
- significantly. Therefore, it can be inferred that not only quantum size effects, but also defects on the surface, contribute to the PL in GQDs. Size and morphology of GQDs were characterized using TEM and AFM. The TEM micrographs shown in Figure 3a confirm the formation of evenly dispersed GQDs with almost
- . 1385 cm−1) and G bands (ca. 1585 cm−1) with an excitation wavelength of 532 nm as shown in Figure 5b, resembling those of a standard graphitic structure [38]. As a result of defects in the sp2-hybridized GQDs structure, the D band occurs due to transverse optical (TO) phonons about the k point of the
Metal-organic framework-based nanomaterials as opto-electrochemical sensors for the detection of antibiotics and hormones: A review
Beilstein J. Nanotechnol. 2023, 14, 631–673, doi:10.3762/bjnano.14.52
- induced by heat. The emission is caused by electrons transitioning from higher-energy molecular orbitals to lower-energy ones, typically the ground state or the lowest empty molecular orbitals. Luminescence may be caused by intrinsic defects, a particular moiety within the compound (metal or ligand
- ), impurity-induced defects, or it may exist in pure crystals or molecules. According to the manner of the substance excitation, several distinct forms of luminescence are differentiated, as shown in Figure 6. A molecule, nanostructure, or atom must be able to absorb light radiation, resulting in electronic
Titania nanoparticles for photocatalytic degradation of ethanol under simulated solar light
Beilstein J. Nanotechnol. 2023, 14, 616–630, doi:10.3762/bjnano.14.51
- (point defects), there are some deviations. The small oxygen deficiency observed even after calcination is related to remaining chlorine impurities and Ti3+ ions that resisted calcination. Phase composition and crystallites sizes of the TiO2 powders were investigated. The X-ray diffractograms of the
- (Figure 2c). The highest number of spheres compared to the total number of particles are in sample TO-850-b (7.6%) and the fewest in sample TO-250-b (1.9%). The HRTEM images (Figure 3) show the crystal structure of the TO-850-a powder with point defects and some residual impurities at the particle surface
- exclude the possibility that these defects are located on the TiO2 surface and that the concentration of defects is below the detection limit of XPS [52][53]. Another explanation would be this: The surface depth sensitivity of XPS is known to be 5–10 nm compared to 1 μm in PL. Hence, this technique
Thermal transport in kinked nanowires through simulation
Beilstein J. Nanotechnol. 2023, 14, 586–602, doi:10.3762/bjnano.14.49
- . Systems where such transport is important are said to have significant ballistic transport compared to the classical scenario, that is, diffusive transport. Ballistic transport can be impacted by features of the system, such as surfaces, edges, defects, and inclusions [7][8][9]. Consequently, the effect
- concentration of heat flux into areas smaller than the wire itself has significant implications for device design. Areas with more significant heat flow can amplify the effects of small changes in the wire. This is particularly true when impurities or defects are a concern [24]. Introduction of a source of
ZnO-decorated SiC@C hybrids with strong electromagnetic absorption
Beilstein J. Nanotechnol. 2023, 14, 565–573, doi:10.3762/bjnano.14.47
- same time, wide effective absorption bandwidth (EAB ≥ 7 GHz) remains a great challenge. A good strategy is to form hierarchical heterostructures, characterized by diverse components, abundant heterogeneous interfaces, multiple reflective paths, and enrichment of structural defects [18][19][20
- amorphous state (Figure 2e). The carbon shell may have a positive effect on the nucleation of ZnO particles. This is because oxygen-containing functional groups (such as carboxyl and hydroxy groups) and structural defects are generated on the SiC@C surface during the in situ carbonization [24], which both
- SiC surface. As described in our previous work [24], the carbon shell may form a conductive network in the SCZ/wax composites (Supporting Information File 1, Figure S6b). Besides, abundant defects (such as nanopores in carbon) can also result in dipole polarization and Debye relaxations [24][38
SERS performance of GaN/Ag substrates fabricated by Ag coating of GaN platforms
Beilstein J. Nanotechnol. 2023, 14, 552–564, doi:10.3762/bjnano.14.46
- plasmonic metals or their alloys [23][24][25][26][27][28][29][30][31][32]. The chemical and electrochemical etching of GaN heteroepitaxial layers leads to various nanostructures formed on line defects (dislocations), such as straight nanopillars, bunches of nanopillars, and pits [31][32]. The nanostructured
- in the formation of nanocolumns on line defects (dislocations), as was demonstrated in [45]. The nanostructured GaN platforms were then coated with Ag using a Quorum Q150TS sputter coater (Quorum Technologies Ltd., Laughton, UK) with a cleaning oxidized target function engaged [32]. The thickness of
Observation of multiple bulk bound states in the continuum modes in a photonic crystal cavity
Beilstein J. Nanotechnol. 2023, 14, 544–551, doi:10.3762/bjnano.14.45
- influenced by both the radiative part Qr and a nonradiative part Qnr via 1/Q = 1/Qr + 1/Qnr provided that the material is lossless. Qnr incorporates defects such as structural disorder, surface roughness, and fabrication errors. The simulation of the unit cell was performed by COMSOL Multiphysics with
- defects are mainly located at the mode node of a specific mode, the loss caused by the defect will decrease. In contrast, disorders at an antinode will lead to obvious loss (small Qnr) and a dominant Q factor degradation. For our sample, a higher loss caused by defects occurs for the mode with shorter
On the use of Raman spectroscopy to characterize mass-produced graphene nanoplatelets
Beilstein J. Nanotechnol. 2023, 14, 509–521, doi:10.3762/bjnano.14.42
- . For example, information on flake size, extent of structural defects, chemical or electronic doping, and strain and layer number can all be extracted from one spectrum [13][14][15][16][17][18]. As such, Raman spectroscopy is widely used by producers to assess the quality of their material, in
Conjugated photothermal materials and structure design for solar steam generation
Beilstein J. Nanotechnol. 2023, 14, 454–466, doi:10.3762/bjnano.14.36
- either undergo radiative relaxation in the form of photons or nonradiative relaxation in the form of phonons (heat) to release and transfer energy to impurities/defects or dangling bonds on the material surface. When energy is released in the form of phonons, local heating of the lattice is induced
Plasmonic nanotechnology for photothermal applications – an evaluation
Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33
- Planck’s constant, and q is the wave vector of the phonon oscillations. These elementary excitation phonons are bosons with a wave vector of k = 2π/λ. Crystal defects and other such sources of anharmonicity can change their frequencies and, hence, their coupling characteristics to electrons and the
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