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In this study, the morphological properties and micro-roughness of chromium thin film prepared by thermal evaporation technique and confirmed via EDS analysis are examined on different substrates of BK7, Silicon (Si), and glass using atomic force microscope analysis (AFM). Analysis of amplitude parameters, Minkowski functionals, and films' spatial microtexture extracted from AFM analysis showed the difference between glass substrate and the other two (BK7 and Si) substrates for the growth of chromium thin films. In addition, we observed robust signatures of multifractality of the Cr thin films deposited on all substrates we studied. Moreover, we highlight that the Glass substrates displayed the strongest multifractality indicating that such samples present space filling properties distributed over more spatial scales than the samples of BK7 and Si.

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.

In this work, the atomic force microscopy (AFM) technique was used to characterize 3D MgF

In this work, nanostructured NiSe thin films were prepared by the chemical solution deposition method at different pH fixing the deposition time. The surface morphology, structural and semiconductor properties of such films were investigated utilizing different methodologies. It was found that slight changes in pH can influence the optical bandgap and structure of NiSe films. The results of Tauc's plot and the derivation of the ineffective thickness method were compared to estimate the optical bandgap energy and the transition index. Additionally, the Urbach energy was also assessed. The potential of the NiSe nanostructured samples as photocatalysts was evaluated by analyzing the decomposition of azoic Congo red dye under visible light radiation.

Utilizing a plasma focus (PF) instrument, magnesium nitride (Mg

In the present study, the physical properties of the ground state in bulk and Co2CrAl Heuslerene compound are investigated by density functional theory (DFT). The effects of exchange-correlation potential on the calculations have been also investigated by GGA, GGA+U, and GGA+U+mBJ approximately. Here, three graphene-like structures with the thickness of about 8 Bohr have been labeled as α, β, and ϒ phases. The results demonstrate the mechanical stability of bulk Co2CrAl since it passes the elastic stability test. Having proved the static stability of the bulk and three Heuslerene shapes of Co2CrAl, it is essential to study dynamic stability as well. The accessible region in the thermodynamic phase diagrams confirms the thermodynamic stability of bulk Co2CrAl and all 2D phases of the compound. According to our electronic calculations, the bulk phase of Co2CrAl is a half-metal whose values of magnetic moment and spin polarization is 3 μB and 100% at the Fermi level, respectively. Besides, α and ϒ phases show the metal behavior for both spin directions in all imposed approximations. Finally, β phase exhibits different magnetic properties for different approximations. From 3eV to 2eV, GGA and GGA+U reveal the magnetic anisotropic and isotropic nature. Besides, an extremely anisotropic nature is observed at the Fermi level by GGA+U+mbJ.

In this study, ZrO2 coatings with different thicknesses were grown by the electron beam evaporation technique. The crystalline structure was studied by XRD analysis which suggested the tetragonal and monoclinic phases for ZrO2 coatings. Additionally, the film thickness slightly enhanced the crystallinity. The surface morphology and fractal features were analyzed using Scanning Electron Microscopy (SEM). The surface statistical parameters and the fractal geometry were employed to analyze the impact of the coating thickness and homogeneity on the morphology of the films. The statistical processing and fractal dimension revealed variations in the morphology parameters due to the electron beam evaporation method applied for different thicknesses of samples. Based on these results, it can be concluded that the surface microtexture and fractal dimension area correlated with the thickness and homogeneity of the crystalline structure.

The aim of the present study is to verify how alternations of annealing temperatures modify optical and micromorphological properties of n-ZnO/p-NZO and n-ZnO/p-NiO multilayers. As can be seen, the optical analysis of homojunctions and hetrojunction thin films shows a red shift by increasing annealing temperature which means that annealing can shift absorption edge coefficient to the lower values of energies. Also, the effective parameters on optical properties of homo- and hetrojunction thin films such as optical band gap, Urbach energy, steepness parameter, and skin depth have been studied by their transmittance spectra. Moreover, the micromorphology of n/p ZnO homo- and heterojunctions transparent diodes have been studied by atomic force microscopy in combination with modern image processing techniques. The nano scaled stereometric analysis provides significant insights into the influence of preparation process on surface texture geometry. According to the results extracted from AFM micrographs by MountainsMap® software, it is observed that Q/ITO/ZnO/NZO sample with 300 °C annealing temperature has the normal distribution of peaks with the highest percentage of isotropy. In addition, it is observed that Q/ITO/ZnO/NiO with 500 °C annealing temperature has the most regular topography.

Using the density functional theory (DFT), some of the electronic (density of states, energy band structure) and optical properties (dielectric function, refractive index, energy loss function) of the novel discovered SnS2 in the cubic structure, have been investigated. The calculations have been performed using the FP-LAPW method. The electronic results reveal that SnS2 in the cubic structure like to SnS2 in the trigonal structure is a semiconductor with an indirect band gap of 1.724 eV which the obtained band gap is in good agreement with experimental band gap of 1.7 eV–1.9 eV. In the optical properties, the real and imaginary parts of the dielectric function have been explored. The calculated optical band gap of 2.27 eV is close to the experimental optical band gap of SnS2 in the cubic structure. The plasmon energy of 19.60 eV has been calculated for this compound. A Sellmeier dispersion relation has been presented for the variation of the refractive index.

Giant magnetoimpedance effect (GMI) in Co 68.15 Fe 4.35 Si 12.5 B 15 amorphous wire was studied in the presence of magnetite ferrofluid and without it. Magnetite nanoparticles for ferrofluid were prepared by the traditional wet chemistry co-precipitation method. GMI was measured in the frequency range of 2 to 6 MHz. The maximum value of GMI value of the ferrofluid covered amorphous wire was increased in all frequency intervals in comparison with GMI response of the wire non-covered by ferrofluid. These results open a new way of increasing magnetoimpedance effect value useful for sensor applications.

The dysprosium oxide nanoparticles’ addition effects on structural, DC electrical resistivity, critical current density, and AC magnetic susceptibility properties of polycrystalline Bi1.6Pb0.4Sr2Ca2Cu3O y samples are investigated. X-ray diffraction (XRD) analysis showed that both (Bi,Pb)-2223 and Bi-2212 phases coexist in the samples having orthorhombic crystal structure. Bi-2223 phase concentration increases with increasing dysprosium nanoparticle concentration. DC electrical resistivity, critical current density (J c), and AC susceptibility measurements reveal that adding dysprosium nanoparticles to bismuth–strontium–calcium–copper–oxide (BSCCO) improves superconducting properties of this system and enhances its critical current density due to the improvement of the grain connectivity with dysprosium nanoparticle addition.

To study the effects of Eu2O3 nanoparticles addition to BSCCO superconducting system, four bulk polycrystalline samples with general formula of Bi1.6Pb0.4Sr2Ca2Cu3Oy+xEu2O3 (where x=0.0, 0.3, 0.5, 1.0 wt%) were prepared by chemical sol–gel method. X-ray diffraction, SEM, and TEM were used for structural characterization of the samples. DC electrical resistivity, critical current, and AC magnetic susceptibility were measured. XRD analysis showed that both (Bi,Pb)-2223 and Bi-2212 phases coexist in the samples having orthorhombic crystal structure. DC electrical resistivity, Jc, and AC magnetic susceptibility measurements reveal that adding Eu nanoparticles to BSCCO improves superconducting properties of this system and enhances its critical current density. The enhancement of the Jc may be caused by improvement of the grain connectivity with Eu nanoparticle additions.

In this research, Dysprosium Oxide (Dysprosia) nanoparticles with the composition, Dy 2 O 3 , were prepared by using the combustion method. The precursor sol was obtained from Dysprosium Nitrate and Glycine was used as the fuel. The molar ratio of cation/glycine = 1.5 was used to prepare very fine powder of dysprosium oxide. The innovative aspect of this method is the preparation of Dy 2 O 3 nanoparticles without applying calcination temperature. To study the effect of the heating and annealing on the structural and optical properties of dysprosia, three different calcination temperatures, 450 °, 550° and 650°C were applied on the initial product (no-calcined sample). Transmission Electron Microscopy (TEM) and X–Ray Diffraction (XRD) were used for structural characterization and Photo Luminescence (PL) was used for studying optical properties of the samples. XRD patterns show the ideal cubic structure for all samples. The crystallite sizes were estimated from the broadening of XRD peaks, using Scherrer’s formula. XRD estimated the crystallite sizes from 24 nm for no-calcined sample to 28 nm for the calcined sample at 650°C. TEM shows the sizes of the particles produced by this method ranged from 5 nm to 100 nm. The samples also exhibited room temperature PL, having a strong emission in the visible region. The band gap of the samples was measured by PL results.

In this research barium carbonate nanoparticle with composition BaCO3 (Witherite) was prepared by using the gel-combustion (sol - gel) method. A precursor sol was obtained from barium nitrate. The molar ratio of citrate/nitrate=1.3 (CA/NO-3 =1.3) was used to prepare very fine powders of barium carbonate. The gels resulting from these sols were transformed into powders by an auto-combustion process at ≤400oC. The powders consisted of orthorhombic BaCO3 and one another additional phase. The barium carbonate nano-particles produced by the gel-combustion method were calcined in three different calcination temperatures T = 450 °C, T = 600 °C and T =750 °C. The pure orthorhombic phase was found at 450oC X-Ray diffraction. The effect of calcination temperature was studied in three various temperatures. The crystallite size XRD was estimated from the broadening of XRD peaks, using Scherrer's formula. Transmission electron microscope (TEM) and X-Ray diffraction (XRD) of the samples were used for characterization of the obtain products. The size of particles were produced by this method are between 1nm to 10nm.

We report the results of a zero-field muon-spin relaxation (ZF-$\ensuremath{\mu}$SR) study of superconducting Ba${}_{1\ensuremath{-}x}$K${}_{x}$Fe${}_{2}$As${}_{2}$ ($0.5\ensuremath{\le}x\ensuremath{\le}0.9$) in search of weak spontaneous internal magnetic fields associated with proposed time-reversal-symmetry-breaking mixed pairing states. The measurements were performed on polycrystalline samples, which do not exhibit the mesoscopic phase separation previously observed in single crystals of Ba${}_{1\ensuremath{-}x}$K${}_{x}$Fe${}_{2}$As${}_{2}$. No evidence of spontaneous internal magnetic fields is found in any of the samples at temperatures down to $T\ensuremath{\sim}0.02$ K.

Based on density functional theory (DFT), some optical properties of InN nanosheet, such as dielectric function, energy loss function, refractive index, reflectivity and absorption coefficient, have been calculated using the modified Becke–Johnson (mBJ) exchange–correlation potential and full potential-linearized augmented plane waves (FP-LAPW) method. The study of dielectric function show that optical properties of InN nanosheet are anisotropic and important energy range in the optical process is between low energies to 20 eV. The results indicate the plasmon energy of InN nanosheet occurs in the lower energy than bulk InN and in addition the plasmon energy in the in-plane direction is different from that perpendicular to the in-plane direction. The obtained optical gaps are 1.2 eV and 3.6 eV in perpendicular and parallel to [Formula: see text]-axis, respectively. Study of refractive index and optical reflectivity shows that the superluminal phenomena occur in the several energy ranges for the InN nanosheet and this nanosheet has high transparency in a wide energy range. The results propose that the InN nanosheet is a good candidate for the optical communications applications, optoelectronics devices and transparent coatings.

In this paper, some structural and electronic properties of V - and Co -doped single-walled ZnO nanotube (8,0), such as cohesive energy, geometric structure, density of states and band structure were investigated using first principles calculations. Our results showed that, first, the pure SWZnONT(8,0) can be stable and second, doped SWZnONTs(8,0) by V and Co atoms are more stable than pure SWZnONT(8,0) and TM impurities distort the structure of nanotubes around the TM impurities. The electronic results showed that pure SWZnONT(8,0) have a direct band gap about 1.443 eV and it is semiconductor. While with substituting V and Co instead of Zn in nanotube, a transition occurs from semiconducting to metallic and half-metallic states which these doped nanotubes as well as their magnetic properties are qualified for using in spintronic devices.

In this report, Dy2O3 (dysprosia) nanoparticles were prepared by using the combustion method. The innovative aspect of this method is preparation of dysprosium oxide nanoparticles without applying calcination temperature. To study the effect of the heating and annealing on the structure of dysprosia, three different calcination temperatures, 450, 550, and 650 °C were applied on the no-calcined sample. TEM and X-ray diffraction XRD were used for characterization of the samples. Diffraction pattern of samples were achieved by selected area electron diffraction (SAED). XRD patterns show the desired cubic structure for all samples. The results of crystallite sizes, estimated by the broadening of XRD peaks, showed the size of crystallites in the range of 24–28 nm. TEM showed the average size of the particles in the range of 28–41 nm.