A lot of duplex and super duplex stainless steels are prone to secondary phases but with different sequence and kinetic which depend on the chemical composition and thermo-mechanical history of the steel. In this paper the results of secondary phase's determination in a welding grade 2510 duplex steel, heat treated at 850–1050°C for 3–30 min are presented. The precipitation stars at grain boundaries with a consistent ferrite transformation for short times. The noses of the TTP curves are at 1000°C (sigma phase) and at 900°C (chi phase) with a partial transformation of chi to sigma, as evidenced in 2205 and 2507 grades.

Nature builds materials like an architect to obtain a variety of properties with a limited number of building blocks. In contrast, engineers have access to a wide range of constituent materials to fulfil a variety of requirements. The classical degrees of freedom for controlling the properties of man-made materials are the microstructure, or the macroscopic shape. Only recently, the architecture at the millimetre scale was perceived as an efficient way of expanding the range of properties offered by bulk materials. The aim of this paper is to compare the different strategies and to outline some observations on natural materials which may serve as inspiration to develop engineering architectured materials.

Titanium doped indium oxide (TIO) thin films were deposited on glass substrate by DC sputtering with different O2/Ar gas ratios at 330 °C. The effects of sputtering on the structural, morphologic, optical and electrical characteristics of TIO thin films were investigated by XRD, Hall measurement and optical transmission spectroscopy. The deposited films exhibited polycrystalline in the preferred (222) orientation, with higher mean grain size and lower resistivity 3.37 ×10-4Ω·cm at O2/Ar ratio of 1/10. The average optical transmittance of the films is over 90%, and the transmittance has no evident change with changing O2/Ar ratio.

The combination of active and passive microrheology using magnetic probes engulfed inside living cells demonstrates the violation of the fluctuation dissipation theorem in cells. It is proposed to quantify the deviation from the in equilibrium situation with an effective temperature. Each magnetic probe then serves as a local thermometer within the cells. The response of pairs of magnetic beads of two diameters (1 and 2.8 μm) to an oscillating magnetic field is analyzed to measure the viscoelastic complex modulus in the beads environment (active measurement). The spontaneous motion of the beads is tracked to compute their mean square displacements (passive measurement). The effective temperature is derived using an extension of the fluctuation dissipation theorem.

Al65Cu15Co20 and Al67Cu13Co20 (% at.) alloys with composition near to the quasicrystalline decagonal phase was produced by melting in an induction furnace and solidified at room temperature. The structural characterization was carried out by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM). For the structural model of decagonal quasicrsytals, it is important to know which crystalline phases have a structural relationship on the formation and decomposition of this type of phases. In the present investigation, the decagonal phase usually coexist with small amounts of the Al(Cu,Co) cubic phase of B2 type. Then, the quasicrystalline (QC) phase is outside of a single-phase region under equilibrium conditions at room temperature. DSC and TGA techniques showed the thermal stability of the alloy system up to 1000 °C.

We investigate boron transient enhanced diffusion (TED) and series resistance in SiGe/Si heterojunction channel pMOSFET. The stress gradient at the SiGe/Si interface near the gate edge in high Ge concentrations are found to determine boron TED as well as extension junction shape, which has a significant impact on the parasitic LDD and source/drain (S/D) series resistance. In addition, high Ge concentrations in the epitaxial SiGe layer on top of Si substrate result in a high sheet resistance during a 1000°C/5s rapid thermal processing (RTP), which is mainly due to alloy scattering and interface roughness scattering.

Silica aerogels were synthesized via sol-gel processing followed by a two-step surface modification and ambient pressure drying, using methyltrimethoxysilane (MTMS) and trimethylchlorosilane (TMCS)/ethanol/n-hexane as surface modification agents. The transparent silica aerogels possessed the porosities, densities and specific surface areas in the range of 87.7–92.3%, 0.27–0.17 g·cm-3 and 852–1005 m2·g-1, respectively. The SEM and HRTEM analysis revealed the three-dimensional nanoporous structure of the silica aerogels. The presence of –CH3 functional groups on the surface of silica particles as indicated by the FTIR spectra was further confirmed by two visible exothermic peaks at 310 and 450–500 °C from the DTA curve. In addition, the silica aerogels were superhydrophobic with the contact angle as high as 160°.

One-dimensional photonic crystals having desired broad region of high reflectance (R) were fabricated by alternating the deposition of amorphous silicon and amorphous silicon nitride layers. The effect of the deposition temperature and angle of incidence on the optical properties of photonic crystals deposited on glass substrate was determined and an excellent matching was found with the simulated results. The broad region of high R of photonic crystals deposited on flat and textured ZnO:Al substrates decreases when compared to the R of photonic crystals de-posited on glass. The performance of amorphous silicon solar cells with 1-D photonic crystals integrated as the back reflector was evaluated. The external quantum efficiency measurement demonstrated that the solar cells with the photonic crystals back reflector had an enhanced re-sponse in the long wavelength region (above 550 nm) compared to the cells with the Ag reflector.

The performance of polymer-based photovoltaic devices is limited by several factors like high band-gap and low charge-carrier mobility, to name a few. Thicker active-layers have high optical absorption but the transport of carriers in them is inefficient. Thus the optimal thickness of the active-layers has to be determined carefully. This conflict can be resolved using a three-dimensional (3D) microscale textured grating shaped solar cell geometry. The solar cells in this study were fabricated on photoresist gratings to give them 3D texture required for enhanced light absorption. Introduction of texturing has a significant effect on over all power conversion efficiency of the devices. Grating based solar cell having 2 micron pitch showed improved power conversion efficiency over the flat solar cell. In addition to favorable guiding of optical modes, the improvement in efficiency is accomplished by homogenous coverage of the spin-coated active layer, which is a challenging process for non-flat surfaces. Uniform thickness in this study was facilitated by the sufficiently high pitch and low height of the underlying photoresist gratings.

The current and luminous efficacy of a red phosphorescent organic light emitting diode (OLED) with sharp interfaces between each of the organic layers can be increased from 18.8 cd/A and 14.1 lm/W (at 1,000 cd/m2) to 36.5 cd/A (+94%, 18% EQE) and 33.7 lm/W (+139%) by the introduction of a layer cross-fading zone at the hole transport layer (HTL) to emission layer (EL) interface. Layer cross-fading describes a procedure of linearly decreasing the fraction in growth rate of an organic layer during deposition over a certain thickness while simultaneously increasing the fraction in growth rate of the following layer. For OLED processing and layer cross-fading organic vapor phase deposition (OVPD) is used. The typical observation of a roll-off in current efficacy of phosphorescent OLED to higher luminance can be reduced significantly. An interpenetrating network of a prevailing hole and a prevailing electron conducting material is created in the cross-fading zone. This broadens the recombination zone and furthermore lowers the driving voltage. The concept of layer cross-fading to increase the efficacies is suggested to be useful in multi-colored OLED stacks as well.

Efficient and practical Raman lasers based on single crystal diamond are now realizable owing to the availability of optical quality crystals grown by chemical vapour deposition. In this paper, the performance characteristics of diamond Raman lasers is summarized and the results compared to other materials. The outlook for diamond Raman lasers is discussed and key challenges for material development highlighted.

In this work, thin ALD alumina films were fabricated for evaluating their capabilities as a barrier material for corrosive environments. The fracture toughness and the corrosion-resisting properties after fatigue cycle of these thin ALD alumina films have been characterized. Indentation tests indicate that the ALD alumina/Al structures could enhance both the yield strength of the metal and the effective fracture toughness of the coated ALD alumina films and this result could be useful for designing nanocomposite structures. However, the test results also indicate that the interfacial strength of the ALD/Al structures was prone to degrade under fatigue loading under corrosive environment. This could potentially be a problem for the long term reliability of related devices operated under a harsh environment. In addition, the strong correlation between indentation behavior and fatigue loading for the structure indicate that nanoindentation response could be possibly used to indicate the damage level of microstructures for future reliability evaluations.

We used a three-dimensional Monte Carlo method to investigate subgrain growth with different initial values for average grain-boundary misorientation, and found that abnormal grain growth emerges for relatively large average misorientation, with remaining cases revealing an exponential kinetics of subgrain growth. We also found that the growth exponent was ˜4.4, and that it was virtually independent of the average misorientation. Self-similarity of the misorientation distribution was observed during growth.

Spherical shaped Si quantum dots (QDs) embedded into the SiO2 substrate are considered in the single sub-band effective mass approach. The electron and heavy hole sub-bands are taken into account. The energy dependence of electron effective mass is applied especially for small size QD. Calculations of low-lying single electron and hole energy levels are performed.For QD of small sizes (diameter D≤6 nm) there is a strong confinement regime when the number of energy levels is restricted to several levels. The first order of the perturbation theory is used to calculate neutral exciton recombination energy taking into account the Coulomb force between electron and heavy hole. The PL exciton data are reproduced well by our model calculations. We also compare the results with those obtained within model [1].For weak confinement regime (size D≥10 nm), when the number of confinement levels is limited by several hundred, we considered the statistical properties of the electron confinement. Distribution function for the electron levels is calculated and results are discussed.

The oxidation of uranium dioxide has been studied for more than 50 years. It was first studied for fuel fabrication purposes and then later on for safety reasons to design a dry storage facility for spent nuclear fuel that could last several hundred years. Therefore, understanding the changes occurring during the oxidation process is essential, and a sound prediction of the behavior of uranium oxides requires the accurate description of the elementary mechanisms on an atomic scale. Only the models based on elementary mechanisms should provide a reliable extrapolation of laboratory results over timeframes spanning several centuries. The oxidation mechanism of uranium oxides requires understanding the structural parameters of all the phases observed during the process. Uranium dioxide crystal structure undergoes several modifications during the low temperature oxidation that transforms UO2 into U3O8. The symmetries and the structural parameters of UO2, β-U4O9, β-U3O7 and U3O8 were determined by refining neutron diffraction patterns on pure single-phase samples. Neutron diffraction patterns, collected during the in situ oxidation of powder samples at 483 K were also analyzed performing Rietveld refinements. The lattice parameters and relative ratios of the four pure phases were measured during the progression of the isothermal oxidation. The transformation of UO2 into U3O8 involves a complex modification of the oxygen sublattice and the onset of complex superstructures for U4O9 and U3O7, associated with regular stacks of complex defects known as cuboctahedra which consist of 13 oxygen interstitial atoms. The structural modifications during the oxidation process are discussed.

The transport of electric charge is an important phenomenon in the systems like interacting quantum dots and molecules, and in polymers, including DNA molecules. We expect that in these nanostructure systems the key role is played by the interaction of the charge carriers with the optical phonons. We show the role of the multiple scattering of the charge carriers on the optical phonons in the inter-molecular transfer. The charge carrier transport based on this mechanism will be discussed theoretically and compared with the earlier experimental results on the charge transport in molecular Donor-Acceptor charge transfer crystals and also in other systems. In order to treat theoretically the electron transfer between two zero-dimensional nanostructures, we will use the model of two interacting quantum dots coupled by the electron inter-dot tunneling mechanism. A connection with the popular Marcus semiclassical charge transfer theory between molecules is also shown. We will use the nonequilibrium quantum electronic transport theory based on the nonequilibrium Green's functions.

A microfabricated amorphous silicon photodiode is used to detect chemiluminescent and colorimetric horseradish peroxidase (HRP) enzymatic reactions. Detections limits of 1 nM and 1 pM of HRP are obtained for chemiluminescent and colorimetric measurements, respectively, with the reactions carried out in solution volume of 50 μL in polystyrene microwells. Surface-adsorbed HRP can be detected with a limit of 1 fmol.cm-2 by both detection methods. Immunoassays were performed using HRP-labeled antibodies and the detection of specific antibody-antigen molecular recognition is demonstrated both in the plastic well and inside a microfluidic channel. The application of the a-Si:H/HRP system is extended by coupling HRP with oxidase enzyme systems for glucose detection and a sensitivity of 0.1 mmol/L was achieved.

Cro/CrOx-doped hybrid glasses are designed to develop novel laser device materials by inserting alkylene spacers between inorganic oxides. In TEM images, morphology of the organically modified hybrid glasses reveals highly arranged nano-periodic patterns. The nano-patterns observed from the hybrid glass based on alkylene-bridged xerogel are sustained over substantial domains and appears to arise from modified glassy lattice fringes. In electron diffraction pattern, it also shows the circled diffraction patterns arise from Cro/CrOx. In laser experiments, the hybrid glass shows a new optical property, which generates a huge acoustic wave; the diffraction efficiency (45 %) of the modified glass is higher than that of methanol (25 %); it means that the compressibility of the solid type of glass is as effective as the liquid. The hybrid glass shows a new optical property that hitherto hasn’t been found and could be useful for developing diffraction beam modulators.

Low dielectric constant (low-k) materials are currently being incorporated into advanced microelectronic devices to improve or maintain performance. As the dielectric constant is reduced, so are its mechanical properties. These reduced properties have recently been related to chip-package interaction (CPI) failures. Significant effort has focused on eliminating CPI failures through engineering of copper crackstop structures. However, published data suggests that crackstop engineering needs to occur at each technology node to ensure CPI reliability. In this study, the focus is on repairing interfacial delaminations with chemistry specific coupling agents rather than attempting to stop them with a specially designed crackstop structure. Critical adhesion values and corrosion resistance of the repaired interfaces are compared to the original interface. The application of the repair chemistry in an integrated structure is discussed along with the potential impact on reliability.

The glass transition of individual electrospun PVA fibers was found using an AFM fiber bending technique within a heated chamber. A considerably loss in the measured elastic modulus was observed with temperature when the glass transition temperature was reached. The glass transition temperature was observed to decrease as the electrospun PVA fiber diameter decreased, indicating diameter dependent enhanced polymer chain mobility.