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We describe the magnetic properties of thin iron films deposited on the nanoporous titanium oxide templates and analyze their dependance on nanopore radius. We then compare the results to a continuous iron film of the same thickness. Additionally, we investigate the evolution of the magnetic properties of these films after annealing. We demonstrate that the M(H) loops consist of two magnetic phases originating from the iron layer and iron oxides formed at the titanium oxide/iron interface. We perform deconvolution of hysteresis loops to extract information for each magnetic phase. Finally, we investigate the magnetic interactions between the phases and verify the presence of exchange coupling between them. We observe the altering of the magnetic properties by the nanopores as a magnetic hardening of the magnetic material. The ZFC-FC (Zero-field cooled/field cooled) measurements indicate the presence of a disordered glass state below 50 K, which can be explained by the formation of iron oxide at the titanium oxide-iron interface with a short-range magnetic order. [ABSTRACT FROM AUTHOR]

In this work, the process of solid-state dewetting in FePd thin films and its influence on structural transformation and magnetic properties is presented. The morphology, structure and magnetic properties of the FePd system subjected to annealing at 600 °C for different times were studied. The analysis showed a strong correlation between the dewetting process and various physical phenomena. In particular, the transition between the A1 phase and L10 phase is strongly influenced by and inextricably connected with solid-state dewetting. Major changes were observed when the film lost its continuity, including a fast growth of the L10 phase, changes in the magnetization reversal behavior or the induction of magnetic spring-like behavior. [ABSTRACT FROM AUTHOR]

In this study, Co/Pt based perpendicular synthetic antiferromagnetic (p-SAF) structures with Ru interlayers are investigated with regard to their magnetotransport properties. The p-SAF structures are varied in their number of Co/Pt multilayer (ML) stacks and Ru interlayers, and are examined for changes in their magnetoresistive effects. The alignment of magnetization directions of the MLs in the ML/Ru/ML stacks of the p-SAF generates a giant magnetoresistance effect (GMR), while the anisotropic magnetoresistance effect (AMR) at each ML further influences the resistance of the system. The GMR is found to increase linearly with the number of Ru interlayers. To extract contributions from the AMR, a simple model is proposed, which explains the observed transfer curves where both effects are taken into account. For the AMR amplitude, it is observed that longitudinal AMR contributions decrease with increasing numbers of Co layers in the p-SAF, whereas transverse components remain constant. While the highest GMR effects are measured at low temperatures, only longitudinal AMR contributions appear to be significantly affected by the measurement temperature. [ABSTRACT FROM AUTHOR]

The present work deals with the corrosion of mild steel (1.0037) used as the outer construction material of the preheater of a modern industrial cement production facility. The facility uses secondary fuels, which introduce considerable amounts of corrosive species. The situation at the examination sites in the preheater zone is tracked over a period of two years including operation and shut-down periods. The investigation is focused on (i) the acquisition of the underlying physicochemical conditions, such as moisture, temperature, and contamination data at the examination site of the preheater, (ii) the multianalytical identification of the formed corrosion products using scanning electron microscopy combined with energy-dispersive X-ray analysis, infrared spectrometry, Raman spectrometry, X-ray diffractometry, and Möβbauer spectrometry, and (iii) voltammetric and EIS laboratory investigations using model solutions. It was evidenced that corrosion takes place at a temperature level of about 100°C in the presence of moisture and oxygen as well as chloride ion as a consequence of the usage of secondary fuels. Typical hot-gas corrosion could be excluded under the current conditions. Appearance, structure, and nature of the corrosion products were found to be not mainly dependent on the varied length of exposure, but on the conditions of the hosting preheater intake. In addition to different FeOOH phases and hematite, magnetite was found, dependent on the oxygen concentration in the process gas. The decisive role of oxygen as key factor for the corrosion rate was electrochemically confirmed. [ABSTRACT FROM AUTHOR]

We report on the X-ray and neutron diffraction and magnetic measurements of the nanosamples of DyMnO3annealed at temperatures of 800 °C, 850 °C and 900 °C. The diffraction data indicate that all the samples crystallize in an orthorhombic crystal structure (space groupPnma). The crystal structure parameters change slightly with preparation. All the samples are antiferromagnets at low temperatures. The Mn magnetic moments order near 40 K, while those of Dy below 8.4 K. The macroscopic magnetic and neutron diffraction data indicate a small difference of properties between the DyMnO3samples synthesized at different temperatures. The observed broadening of magnetic peaks connected with the Dy sublattice suggests a cluster-like character of magnetic ordering. [ABSTRACT FROM PUBLISHER]

We studied the morphology, structure, and magnetic properties of Fe nanowires that were electrodeposited as a function of the electrolyte temperature. The nucleation mechanism followed instantaneous growth. At low temperatures, we observed an increase of the total charge reduced into the templates, thus suggesting a significant increase in the degree of pore filling. Scanning electron microscopy images revealed smooth nanowires without any characteristic features that would differentiate their morphology as a function of the electrolyte temperature. X-ray photoelectron spectroscopy studies indicated the presence of a polycarbonate coating that covered the nanowires and protected them against oxidation. The X-ray diffraction measurements showed peaks coming from the polycrystalline Fe bcc structure without any traces of the oxide phases. The crystallite size decreased with an increasing electrolyte temperature. The transmission electron microscopy measurements proved the fine-crystalline structure and revealed elongated crystallite shapes with a columnar arrangement along the nanowire. Mössbauer studies indicated a deviation in the magnetization vector from the normal direction, which agrees with the SQUID measurements. An increase in the electrolyte temperature caused a rise in the out of the membrane plane coercivity. The studies showed the oxidation resistance of the Fe nanowires deposited at elevated electrolyte temperatures. [ABSTRACT FROM AUTHOR]

In this paper, we describe magnetoelectric properties of metal/metal-oxide/metal junctions based on anodized metal oxides. Specifically, we use Ti and Fe metallic layers separated by the porous metal-oxides of iron or titanium formed by the anodization method. Thus, we prepare double junctions with at least one ferromagnetic layer and measure magnetoresistance, as well as their current-voltage and magnetic characteristics. We find that magnetoresistance depends on that junction composition and discuss the nature of differential resistance calculated from I-V characteristics. Our findings show that a top metallic layer and the interface between this layer and anodized oxide, where strong interatomic diffusion is expected, have the strongest influence on this observed behavior. [ABSTRACT FROM AUTHOR]

In this paper we describe characterization of semi-metallic bismuth thin films. We prepared bismuth thin films by a deposition of bismuth through thermal evaporation onto flexible Kapton substrates and annealing at temperatures close to the melting point of Bi. We studied the morphology and transport properties of these films. Immediately after the deposition we observed competition between vanishing of the grain boundaries and elastic strain energy, which stabilized at larger thicknesses leading to the grain size of 140 nm. This effect was accompanied by a continuous decrease of resistivity which, however, was larger than for the bulk bismuth. The film annealing at temperatures close to the melting point of Bi led to a 300% increase of magnetoresistance at room temperature and in the magnetic field of 7 T. The in situ resistance measurements allowed us to determine the permissible temperature at which the annealing does not cause the loss of film continuity. [ABSTRACT FROM AUTHOR]

Nanotechnology is a very attractive tool for tailoring the surface of an orthopedic implant to optimize its interaction with the biological environment. Nanostructured interfaces are promising, especially for orthopedic applications. They can not only improve osseointegration between the implant and the living bone but also may be used as drug delivery platforms. The nanoporous structure can be used as a drug carrier to the surrounding tissue, with the intention to accelerate tissue–implant integration as well as to reduce and treat bacterial infections occurring after implantation. Titanium oxide nanotubes are promising for such applications; however, their brittle nature could be a significantly limiting factor. In this work, we modified the topography of commercially used titanium foil by the anodization process and hydrothermal treatment. As a result, we obtained a crystalline nanoporous u-shaped structure (US) of anodized titanium oxide with improved resistance to scratch compared to TiO2 nanotubes. The US titanium substrate was successfully modified with hydroxyapatite coating and investigated for bioactivity. Results showed high bioactivity in simulated body fluid (SBF) after two weeks of incubation. [ABSTRACT FROM AUTHOR]

In this paper, we describe a deposition method and investigation of the physical properties of WO3 films. We investigated tungsten oxide due to its potential application as a gas sensor. Thin films of the WO3 were deposited on glass, silicon, and alumina substrates by magnetron GLAD sputtering. The crystallinity of films was determined by X-ray diffraction (XRD) and the thickness by X-Ray Reflectivity (XRR) and spectroscopic ellipsometry (SE). Surface morphology, which is important for gas sensitivity, was measured by atomic force microscopy (AFM). We studied the gas-sensing characteristics under exposure to acetone in the 0.1–1.25 ppm range which covers the levels of exhaled breath acetone. We show that WO3 sensors have different sensitivity for different sputter angle. Furthermore, we demonstrate the influence of temperature during gas content measurement. [ABSTRACT FROM AUTHOR]

Using a two-carriers model and the Hikami-Larkin-Nagaoka (HLN) theory, we investigate the influence of large area patterning on magnetotransport properties in bismuth thin films with a thickness of 50 nm. The patterned systems have been produced by means of nanospheres lithography complemented by RF-plasma etching leading to highly ordered antidot arrays with the hexagonal symmetry and a variable antidot size. Simultaneous measurements of transverse and longitudinal magnetoresistance in a broad temperature range provided comprehensive data on transport properties and enabled us to extract the values of charge carrier densities and mobilities. Weak antilocalization signatures observed at low temperatures provided information on spin-orbit scattering length ranging from 20 to 30 nm, elastic scattering length of approx. 60 nm, and strong dependence on temperature phase coherence length. We show that in the absence of antidots the charge carrier transport follow 2-dimensional behavior and the dimensionality for phase-coherent processes changes from two to three dimensions at temperature higher than 10 K. For the antidot arrays, however, a decrease of the power law dephasing exponent is observed which is a sign of the 1D-2D crossover caused by the geometry of the system. This results in changes of scattering events probability and phase coherence lengths depending on the antidot diameters, which opens up opportunity to tailor the magnetotransport characteristics. [ABSTRACT FROM AUTHOR]

The p-n heterostructures of CuO-Ga2O3 obtained by magnetron sputtering technology in a fully reactive mode (deposition in pure oxygen) were tested under exposure to low acetone concentrations. After deposition, the films were annealed at previously confirmed conditions (400 °C/4 h/synthetic air) and further investigated by utilization of X-ray diffraction (XRD), X-ray reflectivity (XRR), energy-dispersive X-ray spectroscopy (EDS). The gas-sensing behavior was tested in the air/acetone atmosphere in the range of 0.1–1.25 ppm, as well as at various relative humidity (RH) levels (10–85%). The highest responses were obtained for samples based on the CuO-Ga2O3 (4% at. Ga). [ABSTRACT FROM AUTHOR]

Superparamagnetic iron oxide nanoparticles (SPIONs) are promising drug delivery carriers and hyperthermia agents for the treatment of cancer. However, to ensure their safety in vivo, SPIONs must be modified in order to prevent unwanted iron release. Thus, SPIONs were coated with silica layers of different morphologies: non-porous (@SiO2), mesoporous (@mSiO2) or with a combination of non-porous and mesoporous layers (@SiO2@mSiO2) deposited via a sol–gel method. The presence of SiO2 drastically changed the surface properties of the nanoparticles. The zeta potential changed from 19.6 ± 0.8 mV for SPIONs to −26.1 ± 0.1 mV for SPION@mSiO2. The Brunauer–Emmett–Teller (BET) surface area increased from 7.54 ± 0.02 m2/g for SPIONs to 101.3 ± 2.8 m2/g for SPION@mSiO2. All types of coatings significantly decreased iron release (at least 10 fold as compared to unmodified SPIONs). SPIONs and SPION@mSiO2 were tested in vitro in contact with human lung epithelial cells (A549 and BEAS-2B). Both nanoparticle types were cytocompatible, although some delay in proliferation was observed for BEAS-2B cells as compared to A549 cells, which was correlated with increased cell velocity and nanoparticles uptake. [ABSTRACT FROM AUTHOR]

FePd thin films have been recently considered as promising materials for high-density magnetic storage devices. However, it is necessary to find a proper method of fabrication for the (001)-textured and chemically well-ordered alloy. In this paper, we present the detailed investigations of lattice parameters, chemical order degree, grain sizes, and crystallographic texture carried out on FePd alloys with 10 at.% of Cu addition. The initial [Cu(0.2 nm)/Fe(0.9 nm)/Pd(1.1 nm)]5 multilayers were thermally evaporated in an ultrahigh vacuum on MgO(100), Si(100), Si(111), and Si(100) covered by a 100-nm-thick layer of amorphous SiO2. In order to obtain a homogeneous FePd:Cu alloy, the multilayers were annealed in two different ways. First, the samples were rapidly annealed in nitrogen atmosphere at 600 °C for 90 seconds. Next, the long annealing in a high vacuum for 1 h at 700 °C was done. This paper focuses on quantitative investigations of the chemical order degree and crystallographic texture of ternary FePd:Cu alloys deposited on four different substrates. In order to obtain both quantities, we have taken a novel approach to consider the problem of dopant atoms located in the FePd structure. The studies of the structure were done using XRD performed with synchrotron radiation and pole figures measurements. We have found that the addition of Cu changes the FePd lattice parameters and lattice distortion. We have also shown that, using different substrates, it is possible to obtain a FePd:Cu alloy with different chemical order and texture. Moreover, it was observed that the texture category is substrate-dependent. [ABSTRACT FROM AUTHOR]

We present NiO/Ni composite particles with face-centered cubic (fcc) structure prepared by a pulsed laser irradiation of NiO nanoparticles dispersed in liquid. The sizes of particles and the Ni content in NiO/Ni composites were controlled by tuning the laser parameters, such as laser fluence and irradiation time. We found that the weight fraction of Ni has a significant impact on magnetic properties of composite particles. Large exchange bias (HEB) and coercivity field (HC) were observed at 5 K due to the creation of heterojunctions at interfaces of ferromagnetic Ni and antiferromagnetic NiO. For the NiO/Ni composites with 80% of NiO we have observed the largest values of exchange bias (175 Oe) and coercive field (950 Oe), but the increase of Ni weight fraction resulted in the decrease of both HC and HEB values. [ABSTRACT FROM AUTHOR]

Highlights: [•] The laser irradiations transformed FePdCu multilayers, into chemically ordered L10 phase. [•] The (111) crystallites have elliptical shape elongated in direction perpendicular to surface. [•] The (002) crystallites have shape of disks with the longer axis of symmetry parallel to the sample surface. [Copyright &y& Elsevier]

Abstract: The ternary copper indides RE 2CuIn3≡RECu0.5In1.5 (RE=Ce, Pr, Nd, Sm and Gd) were synthesized from the elements in sealed tantalum tubes in an induction furnace. They crystallize with the CaIn2-type structure, space group P63/mmc, with a statistical occupancy of copper and indium on the tetrahedral substructure. These indides show homogeneity ranges RECu x In2− x . Single crystal structure refinements were performed for five crystals: CeCu0.66In1.34 (a=479.90(7)pm, c=768.12(15)pm), PrCu0.52In1.48 (a=480.23(7)pm, c=759.23(15)pm), NdCu0.53In1.47 (a=477.51(7)pm, c=756.37(15)pm), SmCu0.46In1.54 (a=475.31(7)pm, c=744.77(15)pm), and GdCu0.33In1.67 (a=474.19(7), c=737.67(15)pm). Temperature-dependent susceptibility measurements show antiferromagnetic ordering at T N=4.7K for Pr2CuIn3 and Nd2CuIn3 and 15K for Sm2CuIn3. Fitting of the susceptibility data of the samarium compound revealed an energy gap ΔE=39.7(7)K between the ground and the first excited levels. [Copyright &y& Elsevier]