Influence of scanning rate on quality of AFM image: Study of surface statistical metrics

Dual effect to improve the electrical properties of SZO films grown by nitrogen pneumatic spray pyrolysis

The principal aim of this study is to reduce considerably, via Sn doping, the resistivity of ZnO thin films prepared by simple, flexible, and cost-effective nitrogen pneumatic spray pyrolysis (NPSP) method on glass substrates at a temperature of 400°C. Different Sn content was tested (Sn/Zn = 0, 1, 3, 5 wt%) in an attempt to reduce the concentration of excessive oxygen atoms and create more free electrons. The microstructural, optical, morphological, and electrical properties of the films have been studied. The x-ray diffraction analysis demonstrated that tin-doped SZO films exhibited polycrystalline nature with a preferential orientation along (002) plane with the appearance of a new orientation (101) with the increase of Sn concentration leading then to bidirectional growth. The deposited SZO films showed an average optical transmittance of about 80% in the UV-visible region (200-800 nm) with optical band gap values at around 3.27 eV. Photoluminescence emissions of SZO samples presented three main peaks: near band edge emission, violet emission, and the blue-green emission. The surface morphology of the films obtained by scanning electron microscope (SEM) exhibited the change in morphology with increasing the Sn content. A minimum electrical resistivity value of about 17·10-3 Ω·cm was obtained for 3% SZO films. SZO films prepared by the NPSP method can be used as transparent window layer and electrodes in solar cells. RESEARCH HIGHLIGHTS: Highly oriented, conducting, and transparent Sn-doped ZnO films are successfully synthesized. The film growth orientation changed from mono-directional (002) axis to bi-directional (002) and (101) axis according to Sn doping. Ultraviolet and green emissions are noted by photoluminescence investigation. A minimum resistivity is observed for 3 wt% SZO film. The dual positive effect of the carrier gas used (N2) and Sn doping is confirmed.

The impact of helical slide honing on surface microtexture compared to plateau honing process through relevant characterization methods

The cylinder engine surface texture has a major influence on the functional performances of the ring-pack tribo-system. The cylinder engine surface microtexture manufactured by plateau honing (PH) and helical slide honing (HSH) processes have been analyzed using white light interferometry (WLI), and stereometric analysis. The approaches in three-dimensional (3-D) white light interferometer measurements and surface stereometric analysis are important for the correct interpretation of 3-D local surface texture features and can be applied in mathematical models for calculating the friction. The samples were divided into two groups: plateau honing (PH) samples and helical slide honing (HSH) samples to discuss the obtained results, according to the honing techniques obtained after several stages: the rough and finish honing and final stage. The obtained results demonstrated that the surface of group PH has the higher values of root mean square height (Sq = 1.83 μm) and fractal dimension (Df = 2.74 ± 0.01), while the lowest values of root mean square height (Sq = 0.63 μm) and fractal dimension (Df = 2.60 ± 0.01) were found for HSH samples. These values highlight that the PH samples are more irregular (both as surface and topography) in comparison with HSH samples. HIGHLIGHTS: We characterized the micromorphology of surface microtexture in plateau and helical slide honing. The nanostructure morphology was investigated using the white light interferometry, fractal and stereometric analyses. The surface topography during the HSH process has different characteristics than the PH process and can be used to obtain better friction and lubrication performances.

Nanomechanical tribological characterisation of nanostructured titanium alloy surfaces using AFM: A friction vs velocity study

Medical-grade titanium alloys used for orthopaedic implants are at risk from infections and complications such as wear and tear. We have recently shown that hydrothermally etched (HTE) nanostructures (NS) formed on the Ti6AlV4 alloy surfaces impart enhanced anti-bacterial activity which results in inhibited formation of bacterial biofilm. Although these titanium alloy nanostructures may resist bacterial colonisation, their frictional properties are yet to be understood. Orthopaedic devices are encapsulated by bone and muscle tissue. Contact friction between orthopaedic implant surfaces and these host tissues may trigger inflammation, osteolysis and wear. To address these challenges, we performed simulation of the contact behaviour between a smooth control Ti6Al4V alloy and HTE surfaces against a hardwearing SiO₂ sphere using Atomic Force Microscopy (AFM) in Lateral Force Microscopy mode. The friction study was evaluated in both air and liquid environments at high (5 Hz) and low (0.5 Hz) scan velocities. Lower scan velocities demonstrated opposing friction force changes between the two mediums, with friction stabilising at higher velocities. The friction measured on the NS alloy surfaces was reduced by ~20% in air and ~80% in phosphate buffered saline, in comparison to the smooth control surface, displaying a non-linear behaviour of the force applied by the AFM tip. Changes in friction values and cantilever scan velocities on different substrates are discussed with respect to the Stribeck curve. Reduced friction on nanostructured surfaces may improve wear resistance and aid osseointegration.

Surface dynamics, fractal features, and micromorphology analysis of kefir biofilms

We introduce a study of image analysis of kefir biofilms associated with Acai extract prepared by fermentation of fresh kefir grains natural. Atomic force microscopy data were studied, aiming to understand how the concentration of acai berry (Euterpe oleracea Mart.) influences the surface morphology as well as the texture complexity, evaluated by the fractal dimension. The results showed that the superficial morphology was affected by the increase of Acai concentration in the biofilms, as well as the fractal dimension. It has also been observed that the surface of the biofilm presented saturation when concentration changes from 40 to 60 ml. On the other hand, it was observed that the intermediate sample produced with 20 ml of acai berry seems to be the best point for biofilms production that can serve as a skin dressing since other studies related to mechanical properties and in vitro and in vivo tests can confirm this applicability. Thus, the characterization of the surface morphology of kefir biofilms by the evaluation of surface statistical parameters and fractal geometry may provide promising results regarding the applicability of these films. RESEARCH HIGHLIGHTS: We characterized the structural complexity of the 3-D surface of the kefir biofilms associated with açaí extract. The 3-D surface analysis of the samples was performed using an atomic force microscope operating in contact mode. We determined the stereometric and fractal dimension of the analyzed samples.

Multifractal analysis of Mg-doped ZnO thin films deposited by sol-gel spin coating method

A multifractal analysis has been performed on the 3D (three-dimensional) surface microtexture of magnesium-doped zinc oxide (ZnO:Mg) thin films with doping concentration of 0, 2, 4, and 5%. Thin films were deposited onto the glass substrates via the sol-gel spin coating method. The effect of magnesium doping, on the crystal structure, morphology, and band gap for ZnO:Mg thin films has been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and UV-Vis spectroscopy. It has been observed that the surface of ZnO thin films is multifractal in nature. However, multifractality and complexity observed to decrease with increasing content of Mg in ZnO thin films due to formation of islands on the surface in accordance with Volmer-Weber growth mechanism. The investigations revealed that crystallinity, microtexture, morphology, and optical properties of the thin films can be tuned by controlling the Mg content within the ZnO lattice. In particular, their optical band gap energies were 3.27, 3.31, 3.34, and 3.33 eV at 0, 2, 4, and 5%, respectively. The prepared thin films of ZnO:Mg with tuned characteristics would have promising applications in optoelectronic devices.

The electrophoretic deposition of TiB2 nanoparticles produced by pulsed laser ablation: Case study on microstructural features and micromorphology properties

In the last decade, laser Ablation technique (Nd:YAG) has been considered as a perfect method for producing nanostructures with high purity. In the present study, Titanium diboride nanoparticles (TiB₂ NPs) have been deposited on Aluminum (Al) and their micromorphology and microstructural properties have been investigated. The synthesis of TiB₂ NPs has been carried out by the Laser Ablation technique (Nd:YAG) which has not been reported so far. Moreover, the effects of laser energy on improving the synthesis of TiB₂ NPs have been examined. In this regard, five samples of TiB₂ NPs were prepared by Laser Ablation method in different values of laser fluency in the range of 0.4-1.2 J/cm² . The structural properties of prepared nanoparticles were detected by grazing incidence X-ray diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy. The morphology of samples was also investigated by field effect scanning electron microscopy. The results demonstrate the formation of spherical nanoparticles in all samples. Based on the results of the GIXRD patterns, pulsed laser energy is an effective parameter for the size of ablated nanoparticles. As can be seen, increasing the energy of laser beam decreases the average size of nanoparticles from 79.41 to 4 nm. As the next step, the as-prepared nanoparticles were deposited on Aluminum substrate with electrophoretic deposition technique at constant applied voltage (30 Volt) and constant deposition time (30 min). The X-ray diffraction pattern of TiB₂ NPs deposited onto Al substrate confirmed the formation of the TiB₂ thin films on all Al substrates. Also, the roughness and average particle size of deposited films were measured by atomic force microscopy images and MountainsMap® Premium software. Increasing the fluency of laser beam made the surface more irregular and the maximum value of fractal dimension and hence, the most irregular topography has been observed in the sample produced by maximum laser fluency. RESEARCH HIGHLIGHTS: Titanium diboride nanoparticles have been synthesized by the laser ablation technique. The effects of laser energy on improving the synthesis of TiB₂ NPs have been investigated. The micromorphology of samples have been investigated by analyzing AFM and SEM images.

Surface texture and fractal analysis of cemented carbide cutting tools

This work highlights the usefulness of multi-scale-fractal and surface-texture analysis in the machining of cemented carbide cutting edge by electrolytic-abrasive honing (EAH) process. In order to achieve this, a fresh (untreated) cutting edge sample and the same sample after machining by electrolytic-abrasive honing (treated) were studied upon their characteristics of surface texture and material properties to provide manufacturers a sustainable advantage in strengthening their tools. The surface characteristics of untreated and honed samples have been analyzed by evaluating four similar locations in the regions of each sample. Scanning electron microscopy (SEM) has been used for the characterization of materials surface. It was found that the unprepared cutting edge and the electrolytic-abrasive sharp surface regions of the samples could be distinguished by area scale analysis and surface texture characteristics. The present study will help in improving the life span estimation of the tools and highlight the opportunities for the statistical modeling of lubrication mechanisms between the tool and the workpiece.

Stereometric analysis of Ti1- x Alx N thin films deposited by direct current/radio frequency magnetron sputtering

A study of image analysis of Ti_1-x Al_x N films deposited on corning glass substrates by a direct current (DC)/radio frequency (RF) magnetron sputtering system was performed. Atomic force microscopy (AFM) data were studied to understand how the impact of the concentration of Al content influences the 3D surface morphology as well as the surface texture parameters. The results showed that the superficial morphology was modified by the increase of Al content in the Ti_1-x Al_x N films, as well as the surface microtexture. It has also been observed that the Ti_1-x Al_x N film surface with the highest aluminum (Al) doping concentration presented a similar surface morphology to pristine titanium nitride (TiN) thin films. The Abbott-Firestone curves for all films exhibited an S-like shape suggesting topographic uniformity and Gaussian distribution of heights. An increase in surface uniformity is observed with Al concentration. The characterization of the surface morphology of Ti_1-x Al_x N films by the evaluation of surface statistical parameters suggests that the surface topography can be adjusted by suitable doping of aluminum and offers a deeper understanding of the applicability of these films.

Advanced morphological analysis of siloxane-hydrogel contact lenses

The purpose of this work is to provide a better understanding of three-dimensional (3-D) surface texture of siloxane-hydrogel contact lenses (CLs) using atomic force microscopy (AFM) and stereometric analysis. The 3-D surface texture characterization of unworn/worn siloxane-hydrogel CLs made of Filcon V (I FDA group) was performed with stereometric analysis. The atomic force microscopy (AFM) measurements of surface roughness and micromorphology of CLs were made using a Nanoscope V MultiMode (Bruker) in intermittent-contact mode, in air, on square areas of 5 × 5 μm. Stereometric study of 3-D surface texture was made according with ISO 25178-2:2012 for CL_rins (taken from the blister and rinsed with deionized water); CL_ss (preserved for 12 hr in saline solution and rinsed with deionized water); CL_worn-smooth (worn for 8 hr and presenting the smooth type morphology), and CL_worn-sharp (worn for 8 hr and presenting the sharp-type morphology). The 3-D surface texture of siloxane-hydrogel CLs was found to have specific morphological characteristics. Statistical parameters revealed local geometrical and morphological spatial structures at nanometer scale attributed to the specific interactions at the CLs surface. Before wear, the surface micromorphology of Filcon V CLs is regular with uniformly distributed microasperities and relatively small heights (Sq = 0.6 nm). After 12 hr in saline, it is found that the micromorphology changes relatively easily, but retaining the main morphological characteristics (Sq = 1.2 nm). After 8 hr of wear, there are two typical micromorphologies: smooth type, characterized by gutter structures and isolated microasperities (Sq = 2.5 nm), while the sharp type has an appearance with compactly arranged microasperities of hill type flanked by compactly arranged microregions of valley type (Sq = 2.2 nm). Surface statistical parameters allow manufacturers in developing the next generation of CLs with improved surface texture while improving biocompatibility and minimizing the impact of the material on corneal physiology. Furthermore, the micro-elastohydrodynamic lubrication due to surface texture at a nanometer scale between the back surface of the CL with the corneal surface and the front surface of the CL with the under-surface of the eyelid can be deeper and more nuanced to understand in light of modern tribological theories.

Tuning photoluminescence spectra of MoS2 with liquid crystals

The photoluminescence (PL) and Raman spectra of molybdenum disulfide (MoS₂) can be tuned with liquid crystals. A nematic liquid crystal, 5CB, was aligned in a zigzag direction on an MoS₂ monolayer flake. The PL and A_1g Raman mode peaks of the MoS₂ monolayer were shifted by 46 meV and 2 cm^-1, respectively, owing to the interaction between MoS₂ and the liquid crystal. Based on Lorentzian fitting analysis, it was confirmed that the peak positions and intensity ratios of the trion PL and exciton PL varied with the phase transition of the liquid crystal. This phenomenon was possibly caused by the transfer of electrons from MoS₂ to the liquid crystal. This electron transfer varies with the temperature-dependent change in the liquid crystal phase. Therefore, the PL spectra of MoS₂ can be tuned simply by controlling the phase, without changing the type of added material.

Topographic characterization of (Zr, Mn) co-doped bismuth ferrite thin film surfaces

The present work focuses on the investigations on the optical and morphological characteristics of (Zr, Mn) co-doped Bismuth ferrite thin films. Undoped Bismuth ferrite (BiFeO₃ ) and (Zr, Mn) co-doped Bismuth ferrite (ZMBFO) thin films were spin-coated on Pt/TiO₂ /Ti/SiO₂ /Si substrate. X-ray diffraction (XRD) was utilized to confirm the rhombohedral structure and the Scherrer formula was used to calculate the crystallite size of the films. The optical properties were explored using UV-visible spectroscopy and the bandgap energies were calculated using a Tauc plot. The surface morphology of the films was explored with the help of atomic force microscopy (AFM) and the three-dimensional (3-D) surface features were determined using stereometric analyses. The variation of 3-D surface parameters was identified to be the consequence of doping.

Bayesian analysis of Ag thin films formation

A detailed numerical study of the formation of metallic silver thin films ranged from 8 up to 50 nm on thickness is presented. The topography of these films was imaged by Atomic Force Microscopy, and starting from these images, some surface parameters were obtained. We characterized the root mean square roughness evolution by a simple power-law model with a coefficient α=0.74±0.01 consistent with the theoretical results of Family and Vicsek (1985), Family (1990). Additionally, we considered different models to describe the distributions of the grains' heights and sizes, and analyzed them via Bayesian statistics and a Markov Chain Monte Carlo numerical method. This Bayesian analysis has been significantly helpful in this work for allowing the study of the models that represent our data best and considering the experimental errors as instrumental data. The results of this analysis suggest an individual grains' growth followed by a collapse between neighboring grains.

Stereometric characterization of Dinizia excelsa Ducke wood from Amazon rainforest using atomic force microscopy

Dinizia excelsa Ducke under three different cut conditions were carefully analyzed. The morphology and stereometry of different wood cutting surfaces (longitudinal radial, longitudinal tangential, and transversal) were studied by SEM and AFM. The results obtained in this study suggest that both the height parameters and the advanced stereometric parameters of the surfaces did not reveal a significant difference, indicating that the spatial patterns do not change according to the type of cut. In this way, the surface microtexture does not vary depending on the cut type. Similarly, the Hurst's coefficients did not show any significant difference in the spectrum of the PSD fractal region. On the other hand, Minkowski functionals presented a morphological difference between the samples. These results showed that the microtexture of the wood surface does not change as a function of the type of cut submitted to the same polishing process.

Investigation of Stereometric and Fractal Patterns of Spin-Coated LuMnO3 Thin Films

In this paper, we have performed qualitative and quantitative analysis of LuMnO3 thin films surfaces, deposited by spin coating over Pt(111)/TiO2/SiO2/Si substrates, to evaluate their spatial patterns as a function of the film’s sintering temperature. Atomic force microscopy was employed to obtain topographic maps that were extensively analyzed via image processing techniques and mathematical tools. 3D (three-dimensional) topographical images revealed that films sintered at 650°C and 750°C presented the formation of smoother surfaces, while the film sintered at 850°C displayed a rougher surface with a root mean square roughness of ∼2.5 nm. On the other direction, the height distribution of the surface for all films has similar asymmetries and shape, although the film sintered using the highest temperature showed the lower density of rough peaks and a sharper peak shape. The advanced fractal parameters revealed that the film sintered at 850°C is dominated by low spatial frequencies, showing less spatial complexity, higher microtexture homogeneity, and uniform height distribution. These results suggest that the combination of stereometric and fractal parameters can be especially useful for identification of unique topographic spatial patterns in LuMnO3 thin films, helping in their implementation in technological applications, such as photovoltaic solar cells and information magnetic date storage and spintronic devices.

The effect of deposition times in DC-magnetron sputtering on micromorphology of TiO2 thin films

TiO₂ thin films have been prepared by DC-magnetron sputtering process with various deposition times (8, 14, 16, and 20 min) and the micromorphology of their surface has been investigated by means of multifractal analysis. As the main purpose of the manuscript, the topography of all samples are examined by atomic force microscopy (AFM) through the Mountains Map® Premium software which characterizes motifs of significant peaks and pits through stereometric data by the watershed segmentation algorithm. In addition, multifractal features of samples provide deeper insight into texture characteristics and used as the supplementary of the results.

Stereometric and fractal analysis of granulated silver films used in thin-film hybrid structures

Silver nanostructures are of interest to be used in hybrid thin-film structures with various materials. In this work, we analyse 3D AFM images of granulated silver film nanostructures prepared by thermal evaporation. The advanced AFM data study aims to understand how film thickness and postannealing affect the nanostructure morphology changes. For the first time, the evaluation of surface statistical parameters and fractal geometry were used to characterise the nanostructure morphology of Ag island films. The samples with gravimetric thickness of 2, 4 and 10 nm were analysed before and after annealing at 200°C for 10 min. The statistical processing revealed the essential variation of parameters with Ag film thickness increment and as a postannealing result. The nonmonotonic variation of surface roughness, skewness and fractal dimensions were found. It is caused by the features of the film growth process with the thickness increment and thermally activated diffusion of Ag nanoparticles during annealing. LAY DESCRIPTION: Silver nanostructures are of great scientific interest due to their unique properties and wide applicability. In this work, we analyse microscopic 3D images of silver nanostructures deposited on quartz in vacuum chamber. Such thin-film nanostructures consisted of silver nanoparticles attached to the surface of quartz substrate. We aimed at studying how effective film thickness and postannealing affect the nanostructure shapes and forms. Effective thickness is the equivalent thickness of a smooth film. For this purposes we used special parameters called statistical parameters and fractal geometry to investigate nanostructures. The samples with effective thickness of 2, 4 and 10 nm were analysed before and after annealing at 200°C for 10 min. It has been shown, that effective Ag film thickness and postannealing results in variation of nanostructures forms. We have shown that the variation of statistical parameters were nonmonotonic. It is caused by the features of the film growth process with the thickness increment and thermally activated diffusion of Ag nanoparticles during annealing.

The evaluation of surface topography changes in nanoscaled 2,6-diphenyl anthracene thin films by atomic force microscopy

The physical properties of electronic devices made by 2,6-diphenyl anthracene (DPA) are influenced by the microtexture of DPA surfaces. This work focused on the experimental investigation of the 3-D surface microtexture of DPA thin films deposited on OTS (octadecyltrichlorosilane), HMDS (Hexamethyldisilasane), OTMS (octadecyltrimethoxysilane), and Si/SiO₂ (300 nm SiO₂ thickness) substrates with 5 and 50 nm thicknesses and 5 and 10 μm scan size. The thin film surfaces were recorded using atomic force microscopy (AFM) and their images were stereometrically analyzed to obtain statistical parameters, in accordance with ASME B46.1-2009 and ISO 25178-2: 2012. The results showed the effect of different manufacturing parameters on microtexture values where the granular structure is confirmed in all films. In addition, root mean square is increased by increasing the thickness from 5 to 50 nm for all types of substrates.

Force Spectroscopy Imaging and Constriction Assays Reveal the Effects of Graphene Oxide on the Mechanical Properties of Alginate Microcapsules

Microencapsulation of cells in hydrogel-based porous matrices is an approach that has demonstrated great success in regenerative cell therapy. These microcapsules work by concealing the exogenous cells and materials in a robust biomaterial that prevents their recognition by the immune system. A vast number of formulations and additives are continuously being tested to optimize cell viability and mechanical properties of the hydrogel. Determining the effects of new microcapsule additives is a lengthy process that usually requires extensive in vitro and in vivo testing. In this paper, we developed a workflow using nanoindentation (i.e., indentation with a nanoprobe in an atomic force microscope) and a custom-built microfluidic constriction device to characterize the effect of graphene oxide (GO) on three microcapsule formulations. With our workflow, we determined that GO modifies the microcapsule stiffness and surface properties in a formulation-dependent manner. Our results also suggest, for the first time, that GO alters the conformation of the microcapsule hydrogel and its interaction with subsequent coatings. Overall, our workflow can infer the effects of new additives on microcapsule surfaces. Thus, our workflow can contribute to diminishing the time required for the validation of new microcapsule formulations and accelerate their clinical translation.

Multifractal investigation of Ag/DLC nanocomposite thin films

The objective of this study is the experimental investigation of the silver in diamond-like carbon (Ag/DLC) nanocomposite prepared by the co-deposition of radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD) and RF-sputtering. Atomic force microscopy (AFM), X-ray diffraction analyses, ultraviolet-visible (UV-visible) spectroscopy measurements were applied to describe the three-dimensional surface texture data in connection with the statistical, and multifractal analyses. Additional information about structure-property relationships in prepared Ag/DLC nanocomposite was studied in detail to allow a better understanding of the surface micromorphology. The performed analysis revealed the studied samples have multifractal properties and can be included in novel algorithms for graphical representation of complex geometrical shapes and implemented in computer simulation algorithms.

The relation between the average diameter of CNTs on Ni-Cu @ a-C:H catalyst with the optical absorption edge and the optical dispersion parameters

In this study, the average diameter of the grown CNTs on Ni-Cu NPs @ a-C:H substrates were increased by increasing of Cu content. The obtained results indicated that by increase of Cu content, all films exhibited high-absorption spectra; therefore, we were facing an increase in the energy gap of films. The values of dT/dλ and dR/dλ measurements for grown CNTs with 75% Cu shown that maximum values of optical band gap correspond to with values of 2.48 eV and 2.90 eV, respectively. It can be seen that with increase of average diameter of the grown CNTs,  the values of Urbach energy of films were increased. The RBS and EDAX measurements were confirmed presence of Ni and Cu atoms into films. The films deposited with 75% Cu were more smooth. Films deposited with 75% Cu have more disordered. Films deposited with 75% Cu atoms have maximum values of the oscillator strength f and the dispersion energy E_d about of 0.108 eV² and 0.0543 eV, respectively.

Surface micromorphology characterization of PDI8-CN2 thin films on H-Si by AFM analysis

A nanoscale investigation of three-dimensional (3-D) surface micromorphology of archetypical N, N0- bis (n-etyl) x:y, dicyanoperylene- 3, 4:9, 10 bis (dicarboximide) (PDI8-CN2) thin films on H-Si substrates, which are applicable in n-type semiconducting compounds, has been performed by using fractal analysis. In addition, surface texture characteristics of the PDI8-CN2 thin films have been characterized by using atomic force microscopy (AFM) operated in tapping-mode in the air. These analyses revealed that all samples can be described well as fractal structures at nanometer scale and their three dimensional surface texture could be implemented in both graphical models and computer simulations.

Advanced micromorphology study of microbial films grown on Kefir loaded with Açaí extract

In this work, an advanced analysis of the 3D surface microtexture of the microbial films grown on Kefir loaded with Açaí extract was performed. Atomic force microscopy was used to characterize the 3D surface microtexture data in correlation with the stereometric analyses to allow a better understanding of the surface micromorphology consistent with ISO 25178-2: 2012. Two new parameters, fractal succolarity and fractal lacunarity, have been inserted for a quantitative approach to microtexture. The results revealed that the morphology was affected by the increase of the Açaí concentration in biofilms, as well as the fractal succolarity and lacunarity. Adhesive bacteria of the genus Lactobacillus were observed for the lowest concentrations of Açaí. Moreover, it was found that the surface of the biofilms has shown saturation when the concentration has changed from 4 to 6 % of Açaí. These results are of great interest in the characterization of surfaces with promising application like skin dressing.

Micromorphology analysis of TiO2 thin films by atomic force microscopy images: The influence of postannealing

This work describes an analysis of titanium dioxide (TiO₂ ) thin films prepared on silicon substrates by direct current (DC) planar magnetron sputtering system in O₂ /Ar atmosphere in correlation with three-dimensional (3D) surface characterization using atomic force microscopy (AFM). The samples were grown at temperatures 200, 300, and 400°C on silicon substrate using the same deposition time (30 min) and were distributed into four groups: Group I (as-deposited samples), Group II (samples annealed at 200°C), Group III (samples annealed at 300°C), and Group IV (samples annealed at 400°C). AFM images with a size of 0.95 μm × 0.95 μm were recorded with a scanning resolution of 256 × 256 pixels. Stereometric analysis was carried out on the basis of AFM data, and the surface topography was described according to ISO 25178-2:2012 and American Society of Mechanical Engineers (ASME) B46.1-2009 standards. The maximum and minimum root mean square roughnesses were observed in surfaces of Group II (Sq = 7.96 ± 0.1 nm) and Group IV (Sq = 3.87 ± 0.1 nm), respectively.

Stereometric analysis of Ta2O5 thin films

The purpose of this work is the study of the correlation between the thickness of tantalum pentoxide thin films and their three-dimensional (3D) micromorphology. The samples were prepared on silicon substrates by electron beam evaporation. The differences in surface structure of the processed and reference samples were investigated. Compositional studies were performed by energy-dispersive X-ray spectroscopy. Stereometric analysis was carried out on the basis of atomic force microscopy (AFM) data, for tantalum pentoxide samples with 20 nm, 40 nm, 60 nm, 80 nm and 100 nm thicknesses. These methods are frequently used in describing experimental data of surface nanomorphology of Ta2O5. The results can be used to validate theoretical models for prediction or correlation of nanotexture surface parameters.

Polymer Graphite Pencil Lead as a Cheap Alternative for Classic Conductive SPM Probes

This paper presents polymer graphite (PG) as a novel material for the scanning tunneling microscopy (STM) probe. Conductive PG is a relatively modern nanocomposite material used for micro-pencil refills containing a polymer-based binding agent and graphite flakes. Its high conductivity and immunity against surface contamination, with a low price, make it seem like a highly suitable material for electrode manufacturing in general. For the tip production, three methods were developed and are further described in the paper. For the production, three commercially available polymer graphite rods were used. Each has been discussed in terms of performance within the tunneling microscope and within other potential applications.

Evaluation of Topographical Co-Cr-Mo Alloy Surface Changes After Various Finishing Treatments

PURPOSE

To quantify the influence of three different finishing treatments on the cobalt-chromium-molybdenum (Co-Cr-Mo) alloy surface based on stereometric analysis parameters.

MATERIALS AND METHODS

Eighteen specimens were casted from an extra-hard alloy (Wironit^®, BEGO, Bremen, Germany). The samples were distributed into three groups (n = 6 samples per group) dependent on different polishing techniques applied, as follows: A group, only electropolished (EP) samples; B group, after EP, an additional mechanical polishing process was applied to the surface by rubber discs and a polishing paste (RP); C group, after EP, an additional mechanical polishing process was completed by rubber discs, polishing paste and finally by a rotating deer leather wheel (RPDL). Samples were imaged by atomic force microscopy (AFM) in a contact mode, in air, at room temperature.

RESULTS

The evaluation of the microtexture of the sample surface was made based on the 3-D roughness parameters. The lowest statistical surface roughness parameters were found in the RP samples, whereas the highest values were obtained from the EP samples.

CONCLUSIONS

The experiments described can help manufacturers identify the most appropriate parameters and their ranges within which optimal surface characteristics can be achieved.

The effects of deposition time on the nanoscale patterns of Ag/DLC nanocomposite synthesized by RF-PECVD

INTRODUCTION

In this study, a stereometric analysis of the three dimensional (3-D) surfaces of the Ag/DLC nanocomposite synthesized by RF-PECVD was performed.

MATERIALS AND METHODS

Atomic force microscopy in noncontact mode was used to study surface morphology in correlation with multi-parametric statistical analysis. The associated parameters of segmented motifs in conformity with ISO 25178-2:, 2012 have been extracted using MountainsMap® Premium software. The mathematical algorithm computes detached watersheds of hill or dale motifs and determines the maximum and minimum points of motifs.

RESULTS AND DISCUSSION

The stereometric analyses with MountainsMap® Premium software provided detailed information on the 3-D surface topography of samples. Fractal analyses revealed the fractal nature of the performed samples is in correlation with the deposition time of samples. Detailed information of manufactured Ag/diamond-like carbon (DLC) nanocomposite is given based on the information about the surface structure, properties, and performance characteristics. The performed analysis allows the high-resolution modeling of Ag/DLC nanocomposite surface microtexture with motif analysis (intrinsic characteristics disclosure and characterization of surfaces fractal), in order to be included in computer interactive simulation algorithms.

CONCLUSION

It was found the fractal dimension decreases with the increase of the deposition times on samples.