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Steady gravity-capillary periodic waves on the surface of a thin viscous liquid film supported by an air stream on an inclined wall are investigated. Based on lubrication approximation and thin air-foil theory, this problem is reduced to an integro-differential equation. The small-amplitude analysis is carried out to obtain two analytical solutions up to the second order. Numerical computation shows there exist two distinct primary bifurcation branches starting from infinitesimal waves, which approach solitary wave configuration in the long-wave limit when the values of physical parameters are above certain thresholds. New families of solutions manifest themselves either as secondary bifurcation occurring on primary branches or as isolated solution branches. The limiting configurations of the primary solution branches with the increase of two parameters are studied in two different cases, where one and two limiting configurations are obtained, respectively. For the latter case, the approximation of the configurations is given. [ABSTRACT FROM AUTHOR]

Lithium phosphorus oxynitride (LiPON) is an amorphous solid‐state lithium ion conductor displaying exemplary cyclability against lithium metal anodes. There is no definitive explanation for this stability due to the limited understanding of the structure of LiPON. Herein, we provide a structural model of RF‐sputtered LiPON. Information about the short‐range structure results from 1D and 2D solid‐state NMR experiments. These results are compared with first principles chemical shielding calculations of Li‐P‐O/N crystals and ab initio molecular dynamics‐generated amorphous LiPON models to unequivocally identify the glassy structure as primarily isolated phosphate monomers with N incorporated in both apical and as bridging sites in phosphate dimers. Structural results suggest LiPON′s stability is a result of its glassy character. Free‐standing LiPON films are produced that exhibit a high degree of flexibility, highlighting the unique mechanical properties of glassy materials. [ABSTRACT FROM AUTHOR]

With a view to fabricating future flexible electronic devices, an atmospheric-pressure plasma jet driven by 13.56 MHz radio-frequency power is developed for depositing Cu thin films on polyimide, where a Cu wire inserted inside the quartz tube was used as the evaporation source. A polyimide substrate is placed on a water-cooled copper heat sink to prevent it from being thermally damaged. With the aim of preventing oxidation of the deposited Cu film, we investigated the effect of adding H2 to Ar plasma on film characteristics. Theoretical fitting of the OH emission line in OES spectrum revealed that adding H2 gas significantly increased the rotational temperature roughly from 800 to 1500 K. The LMM Auger spectroscopy analysis revealed that higher-purity Cu films were synthesized on polyimide by adding hydrogen gas. A possible explanation for the enhancement in the Cu film deposition rate and improvement of purity of Cu films by H2 gas addition is that atomic hydrogen produced by the plasma plays important roles in heating the gas to promote the evaporation of Cu atoms from the Cu wire and removing oxygen from copper oxide components via reduction reaction. [ABSTRACT FROM AUTHOR]

Ultra-thin ZrB x O y films 5 nm in thickness were prepared by radio-frequency (rf) magnetron sputtering. The thermal stability and the barrier performance against the inter-diffusion between Cu and Si were studied via thermal annealing at different temperatures. The as-deposited amorphous ZrB x O y thin films could effectively block the inter-diffusion of Cu and Si atoms. However, the thin films became invalid at temperatures higher than 600 °C and significant atomic diffusion occurred, resulting in high-resistivity Cu 3 Si compound. Hence, ZrB x O y thin films can be exploited as diffusion barriers in Cu interconnects at temperatures lower than 600 °C. [ABSTRACT FROM AUTHOR]

Highlights: [•] The crystallization of Ru thin films can be suppressed by Zr doping. [•] Amorphous RuZr thin films were fabricated by magnetron sputtering. [•] It could be used to effectively suppress the diffusion between Cu and Si. [ABSTRACT FROM AUTHOR]

CoO/Ag/Fe/Ag(001 ) films were grown epitaxially and studied using magneto-optic Kerr effect and x-ray magnetic circular dichroism (XMCD). Instead of exponential decay as reported in previous works, we find that both the exchange bias and the coercivity in the epitaxially grown films exhibit a nonmonotonous behavior with the Ag spacer layer thickness. By purposely increasing the film roughness, the nonmonotonous interlayer coupling evolves into a monotonie decrease by increasing the Ag thickness. Furthermore, we show that the interlayer coupling peak diminishes or shifts its peak position by inserting a Cr layer between CoO and Ag. [ABSTRACT FROM AUTHOR]

LiNi0.5Mn0.5O2 thin-film electrodes have been prepared by pulsed laser deposition followed by postannealing at different temperatures. The microstructural and morphological characterizations using X-ray diffraction, field-emission-scanning electron microscopy, and Raman spectroscopy measurements show that the structure and phase purity of the thin films are highly dependent on the postannealing temperatures. The films that are postannealed at low temperatures exhibit a relatively lower degree of crystallinity, but a high phase purity. The electronic structure and cation disorder of the LiNi0.5Mn0.5O2 thin-film samples are further investigated by X-ray photoelectron spectroscopy and magnetic property measurement. The charge/discharge behaviors of the thin films that are postannealed at different temperatures indicate that phase-pure LiNi0.5Mn0.5O2 thin films can only be prepared at low annealing temperatures. Electrochemical impedance spectroscopy studies on thin-film electrodes indicate a strong dependence of charge-transfer resistance on the electrode potential. The rate capability and cycling stability in different voltage windows of LiNi0.5Mn0.5O2 thin-film electrodes are further investigated. The relationship between the microstructure and electrochemical properties of LiNi0.5Mn0.5O2 thin-film electrodes has been discussed. [ABSTRACT FROM AUTHOR]

The key challenge to use metallic alloys as anodes in rechargeable lithium batteries is to improve their cycling ability without compromising their high specific capacity. We suggest that an important parameter controlling these two properties is the magnitude of interaction between the active and the inactive components in the alloy system. We demonstrated these ideas on the Al-Cu system by investigating the structure and electrochemical properties of sputtered Al1-xCux (0 < x < 0.37) thin-film alloys. The optimum composition is determined to be ~20 at % Cu. A specific capacity of 792 mAh/g has been obtained for nanostructured Al0.8Cu0.2 with capacity retention of ~50% after 100 cycles. The formation of a supersaturated solid solution structure is also suggested to enhance the electrochemical performance. [ABSTRACT FROM AUTHOR]

Well-crystallized nonstoichiometric LiNi0.5Mn1.5O4–δ thin-film electrodes were prepared by pulsed laser deposition (PLD). The charge/discharge behavior of the nonstoichiometric LiNi0.5Mn1.5O4–δ thin film is consistent with the film having a disordered spinel structure with space group Fd3¯m. These thin-film electrodes exhibit excellent cycle performance and rate capability. The measured Li diffusivity in the film is in the range of 10-12 to 10-10 cm2/s, which is comparable to that of layered LiCoO2. First principles calculations on the stoichiometric (ordered) spinel LiNi0.5Mn1.5O4 find no intermediate ordered phases between LiNi0.5Mn1.5O4 and Li0Ni0.5Mn1.5O4, leading us to speculate that voltage steps observed in experiments are caused by Ni—Mn disorder, which facilitates Li/vacancy ordering. The presence of a smaller step in ‘ordered’ LiNi0.5Mn1.5O4 than in disordered LiNi0.5Mn1.5O4 is consistent with the calculation and may indicate presence of partial disorder even in ordered material. Although a maximum was found for the chemical diffusion coefficient of Li in LixNi0.5Mn1.5O4–δ near x = 0.5, the self-diffusion coefficient exhibits a minimum at that composition. [ABSTRACT FROM AUTHOR]

The phase transitions and electrochemical behavior of LiCoO2 thin-film cathodes prepared by pulsed laser deposition are studied for charging voltages ranging from 4.2 to 4.9 V. Two voltage plateaus at about 4.55 and 4.62 V are observed in the charge- discharge curves. Ex Situ X-ray diffraction measurements confirm structural changes and a phase transition from the O3 to the H1-3 phase when LiCoO2 is charged above 4.5 V. Thin-film LiCoO2 electrodes show stable capacity retention up to 4.5 V but significant capacity fade above 4.5 V, which we attribute to damage from Strain due to phase transitions and Li gradients. Li diffusion in the LixCoO2 thin film up to 4.5 V is investigated by the potentiostatic intermittent titration technique. The chemical diffusion coefficient of Li reaches the maximum near x = 0.4 and starts to decrease when the Li content is further decreased. [ABSTRACT FROM AUTHOR]

Cross-sectional HRTEM micrographs of the Cu/Zr-B-N/Si stacks annealed at (a) 600 °C and (b) 650 °C. • Ultra-thin amorphous Zr-B-N films 5 nm in thickness were fabricated by direct current magnetron sputtering. • The ultra-thin amorphous Zr-B-N films can exist stably up to 650 °C. • They can be adopted as diffusion barrier in Cu interconnects to block the inter-diffusion between Cu and Si atoms. Amorphous Zr-B-N thin films were prepared on Si substrates by DC reactive magnetron sputtering as diffusion barriers for advanced Cu interconnection. To evaluate its thermal stability and barrier performance, Cu/Zr-B-N/Si stacked structures were annealed in high vacuum at temperatures varying from 500 °C to 700 °C for 30 min. The Zr-B-N films remained amorphous after annealing at 600 °C and crystalized at 650 °C, effectively block the intermixing of Cu and Si atoms. However, the thin films became invalid after annealing at 700 °C and high-resistivity Cu 3 Si compounds formed, revealing the significant atomic diffusion between Cu and Si. The excellent barrier performance and high thermal stability of Zr-B-N is attributed to the stable amorphous structure. Therefore, the amorphous Zr-B-N thin film can be exploited as a promising diffusion barrier for Cu interconnect technology. [ABSTRACT FROM AUTHOR]

CoO/Fe thin films were grown epitaxially onto vicinal Ag(001) and investigated using magneto-optic Kerr effect, x-ray magnetic circular dichroism (XMCD), and x-ray magnetic linear dichroism (XMLD) techniques. We show that the CoO film in the ultrathin regime does not induce a uniaxial magnetic anisotropy but a coercivity enhancement. This result provides a mechanism for the microscopic origin of the rotatable magnetic anisotropy. XMLD measurement further reveals that the underlying mechanism is that the CoO spins are totally rotatable in the ultrathin regime to follow the Fe magnetization. [ABSTRACT FROM AUTHOR]

Resistive switching (RS) characteristics of a Pr0.7Ca0.3MnO3 (PCMO) film sandwiched between a Pt bottom electrode and top electrodes (TE) made of various metals are found to belong to two categories. Devices with TE made of Al, Ti, and Ta exhibit a large I-V hysteresis loop and bipolar RS, but those with TE made of Pt, Ag, Au, and Cu do not. Transmission electron microscopy reveals that a thin metal-oxide layer formed at the interface between the former group of TE and PCMO, but not for the latter group of TE. Analysis shows that the categorization depends on the Gibbs free energy of oxidation of the TEs with respect to that of PCMO. [ABSTRACT FROM AUTHOR]

Co thin films were epitaxially grown on Mo(110) and investigated by spin-polarized low-energy electron microscopy. We find that the spin asymmetry of the electron reflectivity from the Co film alternates its sign as a function of both the electron energy and the Co film thickness as a result of spin-polarized quantum well states in the Co film. By measuring spin-dependent quantum well states, we are able to resolve the spin-split energy dispersions of the Co film precisely. The determined spin-resolved energy bands are further tested by fitting the quantum well states using the phase accumulation model, and the result shows an excellent agreement between the fitting and the experimental data. [ABSTRACT FROM AUTHOR]