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Transdermal delivery of amphotericin B, a pharmacological agent with activity against fungi and parasitic protozoa, is a challenge since amphotericin B exhibits poor solubility in aqueous solutions at physiologic pH values. In this study, we have used a laser-based printing approach known as matrix-assisted pulsed laser evaporation to print amphotericin B on the surfaces of polyglycolic acid microneedles that were prepared using a combination of injection molding and drawing lithography. In a modified agar disk diffusion assay, the amphotericin B-loaded microneedles showed concentration-dependent activity against the yeast Candida albicans . The results of this study suggest that matrix-assisted pulsed laser evaporation may be used to print amphotericin B and other drugs that have complex solubility issues on the surfaces of microneedles., Competing Interests: No conflict of interest was reported by the authors. We would like to acknowledge C Mooney (NCSU Analytical Instrumentation Facility) for his aid with electron microscopy, B Andersen for her aid with Fourier transform infared spectrosocpy (NCSU College of Textiles), P Strader (NCSU Analytical Instrumentation Facility) for his aid with nanoindentation, the US National Institutes of Health (Award # 1R21AI117748- 01A1), the US National Science Foundation (Award CMMI 1258536), and the US Office of Naval Research (Award # N00014-15-1-2323). This work was also supported by the National Program PN 4N/2016(1647- LAPLAS IV and a grant of Ministry of Research and Innovation, CNCS - UEFISCDI, Project Number PN- III-P4-ID-PCE-2016-0884, within PNCDI III., (Copyright: © 2017 Sachan, et al.)

This paper presents some studies about the preparation by matrix-assisted pulsed laser evaporation (MAPLE) technique of organic bulk heterojunctions made from the mixture of a star-shaped arylenevinylene compound, 4,4′,4″-tris[(4′-diphenylamino)styryl] triphenylamine as donor and fullerene derivative, [6, 6]-phenyl C61 butyric acid butyl ester, as acceptor, in the weight ratio 1:2. The mixed layer has been characterized by spectroscopic (UV-Vis, Fourier transform infrared) and microscopic (AFM) methods, and the effects of the deposition conditions (number of pulses) and of a buffer layer of poly(aniline-co-aniline propane sulfonic acid) or poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) have been analyzed. The study of the electrical properties has revealed a typical solar cell behavior for the heterostructure glass/ITO/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/4,4′,4″-tris[(4′-diphenylamino)styryl] triphenylamine: [6, 6]-phenyl C61 butyric acid butyl ester/Al, confirming that MAPLE could be an adequate method for the preparation of active layer based on bulk heterojunction for solar cells. [ABSTRACT FROM AUTHOR]

Highlights: [•] SiC films were grown on Si substrates by the pulsed laser deposition technique. [•] Films deposited at temperatures higher than 800°C were dense and polycrystalline. [•] The use of UHV conditions ensured a low oxygen concentration into the SiC films. [ABSTRACT FROM AUTHOR]

Highlights: [•] ZrC and ZrN films were grown by pulsed laser deposition on Si wafers at 500°C. [•] AES investigations results indicated that films contain less than 2% O in bulk. [•] Uniaxial reciprocating sliding tests found a friction coefficient of around 0.3 and a wear rate of only 4.5×10−6 mm3/Nm for the ZrN films. [ABSTRACT FROM AUTHOR]

Highlights: [•] TiN and ZrN films were grown by pulsed laser deposition. [•] XPS results indicated that films contain C atoms bonded into metallic carbide. [•] Films containing carbon exhibited higher hardness values. [Copyright &y& Elsevier]

We report on the selection by combinatorial pulsed laser deposition of Silver-doped Carbon structures with reliable physical-chemical characteristics and high efficiency against microbial biofilms. The investigation of the films was performed by scanning electron microscopy, high resolution atomic force microscopy, energy dispersive X-Ray Spectroscopy, X-ray diffraction, Raman spectroscopy, bonding strength "pull-out" tests, and surface energy measurements. In vitro biological assays were carried out using a large spectrum of bacterial and fungal strains, i.e., Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Enterococcus faecalis and Candida albicans. The biocompatibility of the films obtained was evaluated on MG63 mammalian cell cultures. The optimal combination with reasonable physical-chemical properties, efficient protection against microbial colonization and beneficial effects on human cells was found for Silver-doped Carbon films containing 2 to 7 at.% silver. These mixtures can be used to fabricate safe and efficient coatings of metallic implants, with the goal to decrease the risk of implant associated biofilm infections which are difficult to treat and often responsible for implant failure., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Deposition of bioactive coatings composed of zinc oxide, cyclodextrin and cefepime (ZnO/CD/Cfp) was performed by the Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique. The obtained nanostructures were characterized by X-ray diffraction, IR microscopy and scanning electron microscopy. The efficient release of cefepime was correlated with an increased anti-biofilm activity of ZnO/CD/Cfp composites. In vitro and in vivo tests have revealed a good biocompatibility of ZnO/CD/Cfp coatings, which recommend them as competitive candidates for the development of antimicrobial surfaces with biomedical applications. The release of the fourth generation cephalosporin Cfp in a biologically active form from the ZnO matrix could help preventing the bacterial adhesion and the subsequent colonization and biofilm development on various surfaces, and thus decreasing the risk of biofilm-related infections.

Abstract: The paper investigates the dependence of the optical properties on cation concentration of amorphous-like indium gallium zinc oxide thin films (In Ga Zn1−x O1+0.5x−δ ) with various (In+Ga)/(In+Ga+Zn) and Ga/(In+Ga) ratios obtained by pulsed laser deposition. X-ray reflectivity and spectroscopic ellipsometry thickness results were in good agreement. The proportionality between density and the refractive index in the transparency range is evidenced. The extracted physical parameters are clearly influenced by the variation of cation concentration. [Copyright &y& Elsevier]

We report the film deposition of Poly(D,L-lactide-co-glycolide) (PLGA) particle systems by matrix assisted pulsed laser evaporation (MAPLE) technique. PLGA+polyvinyl alcohol (PVA), PLGA+PVA+ bovine serum albumin (BSA) and PLGA+PVA+chitosan (CH) nanoparticles were prepared by an oil-in-water emulsion-diffusion-evaporation method. The average diameter of PLGA particles was between 180-250 nm. The coatings were obtained by laser evaporation of frozen targets prepared by mixing appropriate PLGA aqueous suspensions and dimethyl sulfoxide (DMSO) in three ratios. Depending on the DMSO content, we deposited PLGA particles embedded into polymeric layer mainly obtained due to the entirely or partially dissolving of nanoparticles into the initial solution. In vitro results showed that the distribution and morphology of osteoblast-like SaOs-2 cells on some PLGA particle coatings were similar with that of the positive control. The purpose of this study was to develop layers of PLGA particles for local controlled drug delivery. [ABSTRACT FROM AUTHOR]

ZrC/TiN and ZrC/ZrN multilayers thinner than 350 nm were grown on (100) Si substrates at a temperature of 300 °C by the pulsed laser deposition (PLD) technique using a KrF excimer laser ( λ=248 nm, pulse duration τ=25 ns, 8.0 J/cm fluence and 40 Hz repetition rate). Cross-sectional transmission electron microscopy, Auger electron spectroscopy depth profiling and simulations of X-ray reflectivity curves indicated that there was intermixing between the deposited layers at the interfaces as well as between the first layer and the substrate. Nanoindentation investigations found hardness values between 35 and 38 GPa for the deposited multilayers. Linear unidirectional sliding wear tests were conducted using a ball-on-plate tribometer under 1 N normal force. Wear tracks were produced in a Hysitron nanoindenter with 1 μm radius diamond tip under a 500 μN load. High-resolution cross-sectional transmission electron microscopy studies of the wear tracks showed that the multilayers withstood these tests without significant damage. The results could be explained by the use of a high laser fluence during deposition that resulted in very dense and strongly adherent nanocrystalline layers. [ABSTRACT FROM AUTHOR]

Abstract: The influence of target–substrate distance during pulsed laser deposition of indium zinc oxide (IZO), indium tin oxide (ITO) and aluminium-doped zinc oxide (AZO) thin films grown on polyethylene terephthalate (PET) substrates was investigated. It was found that the properties of such flexible transparent conductive oxide (TCO)/PET electrodes critically depend on this parameter. The TCO films that were deposited at distances of 6 and 8cm exhibited an optical transmittance higher than 90% in the visible range and electrical resistivities around 5×10−4 Ωcm. In addition to these excellent electrical and optical characteristics the films grown at 8cm distance were homogenous, smooth, adherent, and without cracks or any other extended defects, being suitable for opto-electronic device applications. [Copyright &y& Elsevier]

Abstract: The paper presents the optical properties of amorphous-like indium zinc oxide and indium gallium zinc oxide thin films with various In/(In+Zn) ratios obtained by Pulsed Laser Deposition. Thickness results obtained from simulations of X-ray Reflectivity and Spectroscopic Ellipsometry data were very similar. The dependence of density on stoichiometry resembles the corresponding dependence of the refractive index in the transparency range. A free carrier absorption was noted in the visible spectral range, leading to a weak absorbing thin transparent conductive oxide. On the other hand, the refractive index is smaller than those of based oxides (ZnO and In2 O 3), and counterbalance therefore the weak light absorption. [Copyright &y& Elsevier]

Abstract: Indium zinc oxide films were grown from targets with two different In atomic concentration [In/(In+Zn)] of 40% and 80% by the pulsed laser deposition technique on glass substrates from room temperature up to 100°C. X-ray diffraction and reflectometry investigations showed that films were amorphous and dense. Thin films (thickness<100nm) exhibited higher optical transmittance and resistivities than thick films (thickness>1000nm), probably caused by a significant decrease of oxygen vacancies due to atmosphere exposure. Films deposited from the In rich target under an oxygen pressure of 1Pa exhibited optical transmittance higher than 85%, resistivities around 5–7×10−4 Ωcm and mobilities in the 47–54cm2/Vs range. [Copyright &y& Elsevier]

Thin arsenic-selenium-antimony films (AsSe)Sb ( x=0,5,10,15 mol.%) have been deposited on glass substrates by vacuum thermal evaporation (VTE) and pulsed laser deposition (PLD) techniques from the corresponding bulk glassy materials. The refractive index and the film thickness have been determined from the optical transmission spectra by modified Swanepoel method. The optical band gap calculated using the Tauc's approximation showed a narrowing as a function of the increased Sb content from 1.74 eV to 1.53 eV in the VTE films and from 1.64 eV to 1.42 eV in the PLD films. The refractive index of the Sb-doped films strongly increased with the Sb content and reached the largest value for the PLD films. The results verify that both techniques are suitable for deposition of thin glassy films with high optical quality. [ABSTRACT FROM AUTHOR]

Indium Zinc Oxide compositional libraries were fabricated by combinatorial pulsed laser deposition technique on glass substrate at room temperature. Two pairs of targets with In atomic concentrations, In/(In+Zn), of 28 at.% and 56 at.% or 42 at.% and 70 at.% were employed. A high transparency was observed for all the coatings with transmittance values better than 95%. The maximum thicknesses of the samples, inferred by spectroscopic ellipsometry, were within the 174-310 nm range for the simple PLD films, whereas in case of combinatorial PLD coatings were 341 or 467 nm. Energy dispersive X-ray spectroscopy revealed that In content in the combinatorial films was in the 27-52 at. % range. From atomic force microscopy histograms we evidenced a decrease of the RMS roughness down to 1 nm with the increase of the In content. As a result of the compositional library studies two minimum values of the electrical resistivity were identified at 2.3×10-3 Ω·cm and 8.6 ×10-4 Ω·cm, which correspond to 28.8-29.5 at.% and 44-49 at% range of Indium content. [ABSTRACT FROM AUTHOR]

Abstract: We report on pulsed laser deposition of TiO2 films on glass substrates in oxygen, methane, nitrogen and mixture of oxygen and nitrogen atmosphere. The nitrogen incorporation into TiO2 lattice was successfully achieved, as demonstrated by optical absorption and XPS measurements. The absorption edge of the N-doped TiO2 films was red-shifted up to ∼480nm from 360nm in case of undoped ones. The photocatalytic activity of TiO2 films was investigated during toxic Cr(VI) ions photoreduction to Cr(III) state in aqueous media under irradiation with visible and UV light. Under visible light irradiation, TiO2 films deposited in nitrogen atmosphere showed the highest photocatalytic activity, whereas by UV light exposure the best results were obtained for the TiO2 structures deposited in pure methane and oxygen atmosphere. [Copyright &y& Elsevier]

Abstract: Functionalized implants represent an advanced approaching in implantology, aiming to improve the biointegration and the long-term success of surgical procedures. We report on the synthesis of hydroxyapatite (HA) thin films on polymethylmetacrylate (PMMA) substrates – used as cranio-spinal implant-type structures – by two alternative methods: pulsed laser deposition (PLD) and radio-frequency magnetron sputtering (MS). The deposition parameters were optimized in order to avoid the substrate overheating. Stoichiometric HA structures were obtained by PLD with incident laser fluences of 1.4–2.75J/cm2, pressures of 30–46.66Pa and 10Hz pulses repetition rate. The MS depositions were performed at constant pressure of 0.3Pa in inert and reactive atmospheres. SEM-EDS, XRD, FTIR and pull-out measurements were performed assessing the apatitic-type structure of the prepared films along with their satisfactory mechanical adhesion. Cell viability, proliferation and adhesion tests in osteosarcoma SaOs2 cell cultures were performed to validate the bioactive behaviour of the structures and to select the most favourable deposition regimes. For PLD, this requires a low fluence of 1.4J/cm2, reduced pressure of water vapours and a 100°C/4h thermal treatment. For MS, the best results were obtained for 80% Ar+20% O2 reactive atmosphere at low RF power (∼75W). Cells grown on these coatings exhibit behaviour similar to those grown on the standard borosilicate glass control: increased viability, good proliferation, and optimal cell adhesion. In vitro tests proved that HA/PMMA neurosurgical structures prepared by PLD and MS are compatible for the interaction with human bone cells. [Copyright &y& Elsevier]

Abstract: The aim of this study was to obtain biomimetic inorganic–organic thin films as coatings for metallic medical implants. These contain hydroxyapatite, the inorganic component of the bony tissues, and a natural biopolymer – silk fibroin – added in view to induce the surface functionalization. Hydroxyapatite (HA), silk fibroin (FIB) and composite HA–FIB films were obtained by Matrix Assisted Pulsed Laser Evaporation (MAPLE) in order to compare their physical and biological performances as coatings on metallic prostheses. We used an excimer laser source (KrF*, λ =248nm, τ =25ns) operated at 10Hz repetition rate. Coatings were deposited on quartz, Si and Ti substrates and then subjected to physical (FTIR, XRD, AFM, SEM) analyses, correlated with the results of the cytocompatibility in vitro tests. The hybrid films were synthesized from frozen targets of aqueous suspensions with 3:2 or 3:4 weight ratio of HA:FIB. An appropriate stoichiometric and functional transfer was obtained for 0.4–0.5J/cm2 laser fluence. FTIR spectra of FIB and HA–FIB films exhibited distinctive absorption maxima, in specific positions of FIB random coil form: 1540cm−1 amide II, 1654cm−1 amide I, 1243cm−1 amide III, while the peak from 1027cm−1 appeared only for HA and composite films. Osteosarcoma SaOs2 cells cultured 72h on FIB and HA–FIB films showed increased viability, good spreading and normal cell morphology. The well-elongated, flattened cells are a sign of an appropriate interaction with the MAPLE FIB and composite HA–FIB coatings. [Copyright &y& Elsevier]

The nanohybrid structures consisting of hydroxyapatite (HA) and sodium maleate-vinyl acetate copolymer (MP) deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique on Ti surfaces were investigated for specific biological qualities required in bone implantology. The data from in vitro studies demonstrated that human primary osteoblasts (OBs) firmly adhered to Ti coated with HA–MP as indicated by cytoskeleton and vinculin dynamics. OBs spread onto biomaterial surface and formed groups of cells which during their biosynthetic activity expressed OB phenotype specific markers (collagen and non-collagenous proteins) and underwent controlled proliferation. [ABSTRACT FROM AUTHOR]

Abstract: ZrC films were grown on (100) Si substrates by the pulsed laser deposition (PLD) technique using a KrF excimer laser working at 40Hz. The nominal substrate temperature during depositions was set at 300°C and the cooling rate was 5°C/min. X-ray diffraction investigations showed that films deposited under residual vacuum or under 2×10−3 Pa of CH4 atmosphere were crystalline, exhibiting a (200)-axis texture, while those deposited under 2×10−2 Pa of CH4 atmosphere were found to be equiaxed and with smaller grain size. The surface elemental composition of as-deposited films, analyzed by Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS), showed the usual high oxygen contamination of carbides. Once the topmost 2–4nm region was removed, the oxygen concentration rapidly decreased, down to around 3–8% only in bulk. Simulations of the X-ray reflectivity (XRR) curves indicated a smooth surface morphology, with roughness values below 1nm (rms) and films density values of around 6.30–6.45g/cm3, very close to the bulk density. The growth rate, estimated from thickness measurements by XRR was around 8.25nm/min. Nanoindentation results showed for the best quality ZrC films a hardness of 27.6GPa and a reduced modulus of 228GPa. [Copyright &y& Elsevier]

Abstract: ZrC thin films were grown on (100) Si substrates by the pulsed laser deposition (PLD) technique using a high-repetition rate excimer laser working at 40 Hz. The substrate temperature during depositions was set at 300 °C and the cooling rate was 5 °C/min. X-ray diffraction investigations showed that the films were crystalline. Films deposited under residual vacuum or 2×10−3 Pa of CH4 atmosphere exhibited a (200)-axis texture, while those deposited under 2×10−2 Pa of CH4 atmosphere were found to be equiaxed. The surface elemental composition of as-deposited films, analyzed by Auger electron spectroscopy (AES), showed the usual high oxygen contamination of carbides. Once the topmost −3–5 nm region was removed, the oxygen concentration rapidly decreased, being around 3–4% only in bulk. Scanning electron microscopy (SEM) investigations showed a smooth, featureless surface morphology, corroborating the roughness values below 1 nm (rms) obtained from simulations of the X-ray reflectivity (XRR) curves. From the same simulations we also estimated films mass density values of around 6.32–6.57 g/cm3 and thicknesses that correspond to a deposition rate of around 8.25 nm/min. Nanoindentation results showed a hardness of 27.6 GPa and a reduced modulus of 228 GPa for the best quality ZrC films deposited under an atmosphere of 2×10−3 Pa CH4. [Copyright &y& Elsevier]

Abstract: Zn1− x M x O (M=Co, Ni, Mn) films with different concentrations of transition metal (10–30%) were synthesized by pulsed laser deposition. The substrates were heated at 400 °C and the depositions were performed either under secondary vacuum or under an oxygen pressure of 30 Pa. The occurrence of ion channeling in the films during Rutherford Backscattering Analysis, together with X-ray diffraction, optical absorption and transmission electron microscopy, clearly show that the M atoms are in solid solution on Zn sites. Magnetic properties were investigated by means of magnetometry at 5 and 300 K and Electron Spin Resonance. The Zn1− x Co x O and Zn1− x Ni x O films deposited under low O2 pressure exhibit both a ferromagnetic and a paramagnetic response up to 300 K, while films deposited under high O2 pressure and Zn1− x Mn x O films are paramagnetic. Broad spin resonance peaks are recorded at room temperature, from ferromagnetic films only. The nearly isotropic magnetic response of these films, which is observed in ESR when varying the field orientation with respect to the surface, seems to indicate that the crystalline anisotropy oppose the shape anisotropy, because of the strong [001] texture of the films. [Copyright &y& Elsevier]

Abstract: The extension of pulsed laser deposition to the synthesis on Ti substrates of β-tricalcium phosphate (β-TCP) coatings doped with manganese is reported. Targets sintered from two crystalline Mn-doped β-TCP powders (with the composition Ca2.9Mn0.1(PO4)2 and Ca2.8Mn0.2(PO4)2) were ablated with an UV KrF* (λ =248nm, τ ∼7ns) laser source. X-ray diffraction and energy dispersive X-ray spectroscopy investigations showed that the films, while prevalently amorphous, had a Ca/P ratio of about 1.50–1.52. Scanning electron microscopy analyses revealed a rather homogeneous aspect of the coatings which were molded to the relief of the chemically etched Ti substrate. Fluorescence microscopy was applied to test the proliferation of mesenchymal stem cells grown on the obtained biostructures. Our investigations found that, even 14 days after cultivation, the synthesized films were not cytotoxic. On the contrary, they showed excellent bioactivity, as demonstrated by the neat spread of the cells over the entire surface of Mn-doped β-TCP. When tested in osteoprogenitor cell culture, the Ca2.8Mn0.2(PO4)2 samples revealed a higher potential for proliferation and better viability compared with Ca2.9Mn0.1(PO4)2. [Copyright &y& Elsevier]

Pulsed Laser Photodeposition (PLP) of a-Se from aqueous colloid solutions with KrF laser at a wavelength of λ = 248 nm has been performed. Nanometer thick layers were obtained on quartz substrates in contact with the solution for various Pulse Numbers (PN). Amorphous Se layers, 5–20 nm thick, were obtained typically by 50–500 laser beam pulses of 7 (nsec) duration delivered at RR = 1 Hz with a total fluence of 370 mJ/cm2. The deposited nanometer morphology was analyzed by a Differential-Evanescent Optical Microscopy method and Scanning Electron Microscopy (SEM). The observed leaking electromagnetic field from the waveguide substrates was used to evaluate the thickness profile and growth rate of photodeposited a-Se. Capturing the differential evanescent light leaking image, yielded the PLP nanostructures profiles in the deposited zone. Using this technique in combination with SEM microscopy allowed us to estimate the structural properties of the ultra-thin a-Se nano-structures. [ABSTRACT FROM AUTHOR]

Abstract: The evanescent field propagating in waveguides was used to evaluate the profile and growth rate of laser photodeposited a-Se. A pulsed KrF excimer laser was used for deposition. The differential-evanescent light leaking image, was used to analyze the nanostructures in the deposited zones. The relation between the emerging light intensity of the evanescent wave and the optical light intensity propagating in the waveguide was connected to an effective range of the evanescent wave leaking power into the deposited material. The technique provides the nanometric profiles of the ultra-thin photodeposited structures. [Copyright &y& Elsevier]

Abstract: Pulse shaping introduces the method that makes possible the production of tunable arbitrary shaped pulses. We extend this method to control the prevalent growth of cubic SiC films on Si (100) substrates by pulsed laser deposition at temperatures around 973K from a SiC target in vacuum. We used a laser system generating 200fs pulses duration at 800nm with 600μJ at 1kHz. The obtained structures are investigated by electron microscopy, X-ray diffraction and profilometry. We observed grains embedded in an amorphous texture, characteristic in our opinion to the depositions obtained with very short pulses. We present a comparison of deposited films with and without pulse shaping. Pulse shaping promotes increased crystallization and results in the deposition of thin structures of cubic SiC with a strongly reduced density of particulates, under similar deposition conditions. [Copyright &y& Elsevier]

Abstract: Anatase phase titanium dioxide (TiO2) thin films were grown by pulsed laser deposition on 〈001〉 SiO2 substrates. An UV KrF* (λ =248nm, τ FWHM ≅20ns, ν =2Hz) excimer laser was used for the irradiation of the TiO2 targets. The substrates were kept at room temperature or heated during the film deposition at values within the 100–500°C range. The crystalline quality of the films and their chemical composition were investigated by X-ray diffractometry and energy dispersive X-ray spectroscopy. The optical properties were studied by a double beam spectrophotometer in the spectral range of 400–1200nm. At substrate temperatures higher than 300°C, the structure of the deposited thin films changes from poorly to well crystallised, corresponding to the tetragonal TiO2 anatase phase. The average optical transmittance in the visible-infrared spectral range of the films is higher than 85% which makes them suitable for sensor applications. [Copyright &y& Elsevier]

Abstract: Chromium dioxide is a very suitable compound for spintronic devices. It is ferromagnetic at room temperature (T c =395K) and has a half-metallic band structure. CrO2 has been theoretically predicted to be100% spin polarized at the Fermi level. For some applications in spintronics low deposition temperatures are required. However, the fabrication of single phase thin films of CrO2 at low temperature is quite difficult due to its metastable character. In this work we report our experiments to deposit thin films of chromium oxides by reactive pulsed laser deposition (RPLD). RPLD experiments were performed with a UV KrF* excimer laser source (τ FWHM ≥20ns, λ =248nm) in different conditions regarding the target, the substrate temperature, the atmosphere inside the deposition chamber and the laser fluence. In order to prevent the reduction of CrO2 to Cr2O3 in thin films preserved in ambient conditions some of the samples were capped with gold in situ using the same set-up. The composition and morphology of the deposited films were characterized by X-ray diffraction, scanning electron microscopy and Raman spectroscopy. A higher and stable content of CrO2 in the deposited films was evidenced in the case of samples capped with Au. Subsequent analysis performed after 4 months showed no difference in the content of the film. [Copyright &y& Elsevier]

We report on the successful deposition of high quality type I fibrilar collagen thin films by Matrix assisted pulsed laser evaporation (MAPLE). Thin films deposition was performed in a N2 ambient (20 Pa) using a KrF* laser source (λ=248 nm,τ≥20 ns) operated at a repetition rate of 3 Hz, the incident laser energy at a value within the range (20-35) mJ , and the laser spot area was (3.5-18.5)±0.1 mm2. The collagen films were deposited on double face polished <100> single crystalline Si wafers and characterized by Fourier transform infrared spectroscopy, atomic force microscopy and high-resolution transmission electron microscopy. We demonstrate that our thin films are composed of collagen, with no impurities and the roughness can be controlled by the deposition conditions. [ABSTRACT FROM AUTHOR]

As a result of enormous progress in nanoscale electronics, interest in artificial intelligence (AI) supported systems has also increased greatly. These systems are typically designed to process computationally intensive data. Parallel processing neural network architectures are particularly noteworthy for their ability to process dense data at high speeds, making them suitable candidates for AI algorithms. Due to their ability to combine processing and memory functions in a single device, memristors offer a significant advantage over other electronic platforms in terms of area scaling efficiency and energy savings. In this study, single-layer and bilayer metal–oxide HfO x and TiO y memristor devices inspired by biological synapses were fabricated by pulsed laser and magnetron sputtering deposition techniques in high vacuum with different oxide thicknesses. The structural and electrical properties of the fabricated devices were analysed using x-ray reflectivity, x-ray photoelectron spectroscopy, and standard two-probe electrical characterization measurements. The stoichiometry and degree of oxidation of the elements in the oxide material for each thin film were determined. Moreover, the switching characteristics of the metal oxide upper layer in bilayer devices indicated its potential as a selective layer for synapse. The devices successfully maintained the previous conductivity values, and the conductivity increased after each pulse and reached its maximum value. Furthermore, the study successfully observed synaptic behaviours with long-term potentiation, long-term depression (LTD), paired-pulse facilitation, and spike-timing-dependent plasticity, showcasing potential of the devices for neuromorphic computing applications. [ABSTRACT FROM AUTHOR]

Tooth loss replacement using dental implants is becoming more frequent. Traditional dental implant materials such as commercially pure titanium and titanium aluminum vanadium alloys have well-proven mechanical and biological properties. New titanium alloying metals such as niobium provide improved mechanical properties such as lower elastic modulus while displaying comparable or even better biocompatibility. Hydroxyapatite coatings are a well-documented and widely used method for enhancing dental implants' surface characteristics and properties and could provide a useful tool for further enhancing titanium–niobium implant properties like osteointegration. Among several coating techniques, physical deposition methods and, in particular, vapour deposition ones are the most used due to their advantages compared to wet deposition techniques for hydroxyapatite coating of metallic surfaces like that of dental implants. Considering the scarcity of data concerning the in vivo evaluation of titanium–niobium biocompatibility and osteointegration and the lack of studies investigating coating these new proposed alloys with hydroxyapatite, this review aims to further knowledge on hydroxyapatite-coated titanium niobium alloys. [ABSTRACT FROM AUTHOR]

This study offers a comprehensive summary of the current states as well as potential future directions of transparent conducting oxides (TCOs), particularly tin-doped indium oxide (ITO), the most readily accessible TCO on the market. Solar cells, flat panel displays (FPDs), liquid crystal displays (LCDs), antireflection (AR) coatings for airbus windows, photovoltaic and optoelectronic devices, transparent p–n junction diodes, etc. are a few of the best uses for this material. Other conductive metals that show a lot of promise as substitutes for traditional conductive materials include copper, zinc oxide, aluminum, silver, gold, and tin. These metals are also utilized in AR coatings. The optimal deposition techniques for creating ITO films under the current conditions have been determined to be DC (direct current) and RF (radio frequency) MS (magnetron sputtering) deposition, both with and without the introduction of Ar gas. When producing most types of AR coatings, it is necessary to obtain thicknesses of at least 100 nm and minimum resistivities on the order of 10−4 Ω cm. For AR coatings, issues related to less-conductive materials than ITO have been considered. [ABSTRACT FROM AUTHOR]

Transition metal nitrides have extensive applications, including magnetic storage devices, hardware resistance coatings, and low-temperature fuel cells. This study investigated the structural, electrical, and mechanical properties of thin zirconium nitride (ZrN) films by examining the effects of laser irradiation times. Thin ZrN films were deposited on glass substrates using pulsed DC magnetron sputtering and irradiated with a diode laser for 6 and 10 min. Characterization was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), nanoindentation, and four-point probe techniques. Extended laser irradiation times resulted in increased numbers of peaks on XRD analysis, indicating enhanced crystalline behavior of thin ZrN film. SEM analysis revealed surface voids, while HRTEM showed nanostructured ZrN with uniform plane orientation. The electrical properties of the thin ZrN film improved with extended laser irradiation, as demonstrated by a reduction in sheet resistance from 0.43 × 109 Ω to 0.04 × 109 Ω. Additionally, nanoindentation tests revealed an increase in hardness, rising from 8.91 GPa to 9.36 GPa. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HAp) is one of the most widely studied materials for utilization in the development of artificial implants. Research is mainly aimed at the production and modification of HAp coatings for simplification of the deposition process, cost reduction, and increase in biocompatibility. In this paper, the authors deposited HAp synthetic microparticles by means of matrix-assisted pulsed laser evaporation (MAPLE) on Ti6Al4V alloy plate substrates and obtained uniform HAp coatings without further treatment or modifications. The authors utilized a tunable pulsed laser to adjust its wavelength to the selected solvents, in order to optimize the process for deposition speed and quality. The following solvents were used as matrices: deionized water, isopropyl alcohol, and a 3:2 mixture of isopropanol:acetonitrile. Obtained coatings were examined by means of scanning electron microscopy, Raman spectroscopy, X-ray diffraction, and profilometry in order to evaluate coating quality, uniformity, and structural integrity. MAPLE deposition allowed the acquisition of approx. 200 nm thick coatings for water and isopropanol matrices and approx. 320 nm for isopropanol:acetonitrile matrix, which indicates an increase in deposition rate by 37%. The obtained coatings meet requirements for further biocompatibility testing, material modification, and composite synthesis. [ABSTRACT FROM AUTHOR]

This review is an extensive collection of the latest literature describing the current knowledge about nanohydroxyapatite in a comprehensive way. These are hydroxyapatite particles with a size below 100 nm. Due to their size, the surface area to mass ratio of the particles increases. They are widely used in medicine due to their high potential in regenerative medicine, as a carrier of various substances, e.g., in targeted therapy. The aim of this article is to present the biological and physicochemical properties as well as the use of nanohydroxyapatite in modern medicine. Due to the potential of nanohydroxyapatite in medicine, further research is needed. [ABSTRACT FROM AUTHOR]

Nanotubular hafnia arrays hold significant promise for advanced opto- and nanoelectronic applications. However, the known studies concern mostly the luminescent properties of doped HfO2-based nanostructures, while the optical properties of nominally pure hafnia with optically active centers of intrinsic origin are far from being sufficiently investigated. In this work, for the first time we have conducted research on the wide-range temperature effects in the photoluminescence processes of anion-defective hafnia nanotubes with an amorphous and monoclinic structure, synthesized by the electrochemical oxidation method. It is shown that the spectral parameters, such as the position of the maximum and half-width of the band, remain almost unchanged in the range of 7–296 K. The experimental data obtained for the photoluminescence temperature quenching are quantitatively analyzed under the assumption made for two independent channels of non-radiative relaxation of excitations with calculating the appropriate energies of activation barriers—9 and 39 meV for amorphous hafnia nanotubes, 15 and 141 meV for monoclinic ones. The similar temperature behavior of photoluminescence spectra indicates close values of short-range order parameters in the local atomic surrounding of the active emission centers in hafnium dioxide with amorphous and monoclinic structure. Anion vacancies V O − and V O 2 − appeared in the positions of three-coordinated oxygen and could be the main contributors to the spectral features of emission response and observed thermally stimulated processes. The recognized and clarified mechanisms occurring during thermal quenching of photoluminescence could be useful for the development of light-emitting devices and thermo-optical sensors with functional media based on oxygen-deficient hafnia nanotubes. [ABSTRACT FROM AUTHOR]

Magnesium (Mg) has attracted considerable attention as a biodegradable material for medical implants owing to its excellent biocompatibility, mitigating long-term toxicity and stress shielding. Nevertheless, challenges arise from its rapid degradation and low corrosion resistance under physiological conditions. To overcome these challenges, titanium (biocompatibility and corrosion resistance) has been integrated into Mg. The incorporation of titanium significantly improves mechanical and corrosion resistance properties, thereby enhancing performance in biological settings. Mg–Ti alloys are produced through mechanical alloying and spark plasma sintering (SPS). The SPS technique transforms powder mixtures into bulk materials while preserving structural integrity, resulting in enhanced corrosion resistance, particularly Mg80-Ti20 alloy in simulated body fluids. Moreover, Mg–Ti alloy revealed no more toxicity when assessed on pre-osteoblastic cells. Furthermore, the ability of Mg–Ti-based alloy to create composites with polymers such as PLGA (polylactic-co-glycolic acid) widen their biomedical applications by regulating degradation and ensuring pH stability. These alloys promote temporary orthopaedic implants, offering initial load-bearing capacity during the healing process of fractures without requiring a second surgery for removal. To address scalability constraints, further research is necessary to investigate additional consolidation methods beyond SPS. It is essential to evaluate the relationship between corrosion and mechanical loading to confirm their adequacy in physiological environments. This review article highlights the importance of mechanical characterization and corrosion evaluation of Mg–Ti alloys, reinforcing their applicability in fracture fixation and various biomedical implants. [ABSTRACT FROM AUTHOR]

Nowadays, the development of devices based on organic materials is an interesting research challenge. The performance of such devices is strongly influenced by material selection, material properties, design, and the manufacturing process. Usually, buckminsterfullerene (C60) is employed as electron transport material in organic photovoltaic (OPV) devices due to its high mobility. However, considering its low solubility, there have been many attempts to replace it with more soluble non-fullerene compounds. In this study, bulk heterojunction thin films with various compositions of zinc phthalocyanine (ZnPc), a perylene diimide derivative, or C60 were prepared by matrix-assisted pulsed laser evaporation (MAPLE) technique to assess the influence of C60 replacement on fabricated heterostructure properties. The investigations revealed that the optical features and the electrical parameters of the organic heterostructures based on this perylene diimide derivative used as an organic acceptor were improved. An increase in the JSC value (4.3 × 10−4 A/cm2) was obtained for the structures where the perylene diimide derivative acceptor entirely replaced C60 compared to the JSC value (7.5 × 10−8 A/cm2) for the heterostructure fabricated only with fullerene. These results are encouraging, demonstrating the potential of non-fullerene compounds as electron transport material in OPV devices. [ABSTRACT FROM AUTHOR]