Measuring Na in silicate glasses can be difficult in transmission electron microscopy due to modifications induced by electron irradiation. The modifications involve not only the loss of Na from the illuminated region, but also the formation of Na and Na2O. This work compares the electron energy loss spectroscopy (EELS) of plasmon and Na L23 edge in Na2O–SiO2 glass with those in Na and Na2O. The interpretations of the fine structures in Na L23 edge were also given with the aid of full multiplescattering calculations. It demonstrates that the formation of metallic Na can be easily identified by its bulk plasmon at about 5.8 eV, and the formation of Na2O can be better seen by Na L23-edge fine structure.

Hydrothermal treatment has been applied successfully to convert amorphous titania films to crystalline anatase at 120 °C, a temperature compatible with most polymeric substrates. The amorphous films were deposited at 80 °C using atomic layer deposition (ALD). The crystallinity of the films was monitored by x-ray absorption near edge structure (XANES), and the film composition was determined by x-ray photoelectron spectroscopy (XPS). The effect of precursor chemistry and substrate material was investigated. It was found that titania films produced from Ti isopropoxide are easier to crystallize than those from Ti tetrachloride as the Ti precursor. The amorphous to crystalline transformation can be achieved more readily with films deposited on Si than polycarbonate substrates. The effect of a “seed” layer on the amorphous to crystalline transformation was also studied. Preformed anatase crystallites between the Si substrate and the amorphous film were shown to accelerate the crystallization process. The possible mechanisms responsible for the phase transformation are discussed.

The primary tool for mechanical characterization of surfaces and films is instrumented indentation using the Oliver-Pharr data analysis method. However, this method measures contact area between the indenter and sample indirectly, thus confounding instrumented indentation tests when characterizing dynamic properties, thin films, and materials that “pileup” around the indenter. Here, we demonstrate an electrical technique to continuously measure the in situ contact area by relating nonlinear electrical contact current–voltage (I–V) curves to the instantaneous contact area. Using this approach, we can obtain hardness as a continuous function of applied force.

Indentation stress relaxation tests were carried out on high-purity polycrystalline copper specimens at room temperature with a flat cylindrical indenter. The experimental results showed that the resulting load-time relaxation curves can be described by a power law, which coupled an internal stress and an integral constant between the effective stress and relaxation time. Then the internal stress, integral constant, and dislocation velocity stress exponent can be extracted from load relaxation curves. The derived values from this way were consistent with the results of conventional uniaxial compression stress relaxation tests. These agreements are not only useful to understand deformation (dislocation) mechanisms under the indenter, but also exhibit an attractive potential of measuring nano/micromechanical properties of materials by indentation test.

Based on the classical wetting theories, two theoretically predicted formulas of the apparent contact angles on square-pillar-array microstructured surfaces for Wenzel mode and Cassie mode have been derived, respectively. The theories of superhydrophobic stability on microstructured surfaces have been summarized. Four square-pillar-array samples were fabricated on titanium substrates by using the femtosecond laser micromachining technology, and wettability was analyzed by both experimental and analytical methods. The results showed that the titanium-based surfaces are superhydrophobic. The maximal apparent contact angle is up to 156.9°, while the corresponding sliding angle is 4.7°. Testing of the superhydrophobic stability of the surfaces showed that the maximal deviation of the apparent contact angles is only 0.6°. Analyses indicate that the stable superhydrophobicity of the supplied titanium-based surfaces is within a certain range and not perfect. To improve that, a practical controllable method is proposed herein for the design of a stable superhydrophobic surface.

The optical and electrical properties of “tilted” and “spiral” indium tin oxide (ITO) thin films are reported. The influence of the flux incident angle on the optical and electrical properties is investigated. When the flux incident angle is increased, both the refractive index and extinction coefficient of the film are decreased, but the resistivity is increased. Thus, the physical properties of the film can be modified over a wide range by adjusting the flux incident angle and substrate rotation scheme. It is suggested that the oblique angle deposition technique provides ITO films with more application possibilities by allowing their optical and electrical properties to be tailored.

A co-sputtering system was used to deposit silicon nanoclusters embedded in zinc oxide matrix (Si:ZnO) at low temperature without post-annealing. By adjusting the radio frequency power of the Si target during co-sputtering, Si:ZnO films with various crystallographic structures can be obtained. Silicon nanoclusters embedded in the zinc oxide matrix were examined using a high-resolution transmission electron microscope, x-ray diffractometer, and Fourier transformation infrared spectrometry. By comparing with photoluminescence spectra, we can clearly identify quantum confinement effect of silicon nanoclusters embedded in the ZnO matrix.

We obtained Ba3Yb(BO3)3 single crystals by the flux method with solutions of the BaB2O4–Na2O–Yb2O3 system. The evolution of the cell parameters with temperature shows a slope change at temperatures near 873 K, which may indicate a phase transition that is not observed by changes appearing in the x-ray powder patterns or by differential thermal analysis (DTA). The evolution of the diffraction patterns with the temperature shows incongruent melting at temperatures higher than 1473 K. DTA indicates that there is incongruent melting and this process is irreversible. Ba3Yb(BO3)3 has a wide transparency window from 247 to 3900 nm. We recorded optical absorption and emission spectra at room and low temperature, and we determined the splitting of Yb3+ ions. We used the reciprocity method to calculate the maximum emission cross section of 0.28 × 10−20 cm2 at 966 nm. The calculated lifetime of Yb3+ in Ba3Yb(BO3)3 is τrad = 2.62 ms, while the measured lifetime is τ = 3.80 ms.

The SHS reaction in the Ni–Ti–B4C system starts with the formation of Ni–Ti and Ni–B intermetallic compounds from the solid interacted reaction among the reactants and, subsequently, the formation of Ni–Ti and Ni–B liquid at the eutectic point. Meanwhile, some C atoms from the reaction between Ni and B4C can dissolve into Ni–Ti liquid to form TiC. The heat generated from these reactions can promote the mutual diffusion of Ni–Ti–C and Ni–B liquid and simultaneously accelerate the formation of Ni–Ti–C–B liquid. Finally the precipitation of TiC and TiB2 occur when the C and B atoms in the liquid become supersaturated. The addition of Ni not only promotes the occurrence of the self-propagating high temperature synthesis (SHS) reaction by forming Ni–Ti liquid, but also accelerates the SHS reaction by forming Ni–B liquid and dissociative C. The early appearance of dissociative C from the reaction between Ni and B4C causes the formation of TiC prior to that of TiB2.

Geometrical self-similarity is a feature of mathematically sharp indenters such as conical and Berkovich indenters. However, self-similarity is considered inappropriate for practical use because of inevitable indenter tip blunting. In this study, we analyze the load–depth curves of conical indenters with various tip radii via finite element analyses. Based on the numerical data, we propose a method of restoring the Kick’s law coefficient C of finite tip-radius indenter to that of zero tip-radius indenter, thereby retaining the self-similarity of the sharp indenter. We then regress the unloading slope for the evaluation of elastic modulus in several ways. Finally, we establish a method to evaluate elastic modulus, which successfully provides the value of the elastic modulus with a maximum error of less than 5%, regardless of tip radius and material properties of both indenter and specimen.

A method for evaluating true interlamellar spacing from micrographs is proposed for a multidomained lamellar structure. The microstructure of these materials is assumed to be composed of many domains with the lamellae aligned roughly parallel to each other within each domain and with the domains themselves randomly oriented relative to one another. An explicit expression for the distribution of apparent interlamellar spacing is derived assuming that the distribution of the true interlamellar spacing is Gaussian. The average interlamellar spacing is close to the peak interlamellar spacing observed in the distribution. The theoretical distributions are compared with experimental ones obtained by analyzing micrographs of PbTe–Sb2Te3 lamellar composites.

The effect of minor transition metal (TM) additives of Ni, Co, or Zn on the interfacial reactions of the solder joints between Sn–Ag–Cu (SAC) solder and the Cu/Ni(P)/Au substrate was investigated, especially subsequent to multi-reflowing. (Cu,Ni)6Sn5 formed at the interface of all the joints except that of SAC–Ni, of which the interfacial compound was (Ni,Cu)6Sn5. The interfacial compounds of the SAC–Co and SAC–Zn contained a small amount of alloying elements of less than 3 at.%. Two P-rich layers, Ni3P and Ni–Sn–P emerged at the interface of the SAC joints. Nanoindentation analysis indicates that the hardness and Young’s modulus of these two phases were slightly higher than those of the Ni(P) substrate, which were in turn much greater than those of the Cu–Ni–Sn compounds. Worthy of notice is that with TM additions, the Ni–Sn–P phase between Ni3P and interfacial compounds was absent even after 10 reflows. For the SAC–Co joints, the growth of Ni-containing intermetallic compounds within the solder gave rise to the excess Ni dissolution, which caused a discrete Ni3P layer and over-consumed Ni(P) substrate underneath the grooves in-between (Cu, Ni)6Sn5 scallop grains at the interface. This phenomenon is presented for the first time, and the mechanism is proposed in this study.