We present ALMA detection of the [O iii] 88 μm line and 850 μm dust continuum emission in a Y-dropout Lyman break galaxy, MACS0416_Y1. The [O iii] detection confirms the object with a spectroscopic redshift to be z = 8.3118±0.0003. The 850 μm continuum intensity (0.14 mJy) implies a large dust mass on the order of 4×106M⊙. The ultraviolet-to-far infrared spectral energy distribution modeling, where the [O iii] emissivity model is incorporated, suggests the presence of a young (τage ≍ 4 Myr), star-forming (SFR ≍ 60M⊙yr−1), and moderately metal-polluted (Z ≍ 0.2Z⊙) stellar component with a stellar mass of 3 × 108M⊙. An analytic dust mass evolution model with a single episode of star formation does not reproduce the metallicity and dust mass in ≍ 4 Myr, suggesting an underlying evolved stellar component as the origin of the dust mass.

We have investigated an influence of positive polarization charges generated at an interface between GaN barrier/p-AlGaN EB (Electron Blocking) layer in a blue-LED. Simulation results suggested that such polarization charges caused an electron overflow from QWs. The simulation results also indicated that sufficient acceptor doping at the interface could neutralize the positive polarization charges and suppress the electron overflow. We then demonstrated the electron overflow caused by the positive polarization charges and its suppression with sufficient Mg doping at the interface by monitoring emissions from an additional second QW inserted between the p-EB layer and the p-GaN layer. Finally we conclude that the contribution of the electron overflow is not significant for the efficiency droop in blue-LEDs.

We investigated MOVPE growth conditions for AlInN layers with high growth rates and obtained 0.5µm/h with smooth surfaces. We found that short gas mixing time, relatively high growth temperature, and very low In/Al supply ratio were key growth parameters in order to obtain the AlInN layers with high growth rate and smooth surface simultaneously. AlInN/GaN DBRs grown under such growth conditions showed smooth surfaces and a reflectivity of over 99%.

Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

Leveraging past research activities in orientation control of lead zirconate titanate (PZT) thin films [1,2], this work attempts to optimize those research results using the fabrication equipment at the U.S. Army Research Laboratory so as to achieve a high degree of {001}- texture and improved piezoelectric properties. Initial experiments examined the influence of Ti/Pt and TiO2/Pt thins films used as the base-electrode for chemical solution deposition PZT thin film growth. In all cases, the starting silicon substrates used a 500 nm thermally grown silicon dioxide. The Pt films were sputter deposited onto highly textured titanium dioxide films grown by a thermal oxidation process of a sputtered Ti film [3]. The second objective targeted was to achieve highly {001}-textured PZT using a seed layer of PbTiO3 (PT). A comparative study was performed between Ti/Pt and TiO2/Pt bottom electrodes. The results indicate that the use of a highly oriented TiO2 led to highly {111}-textured Pt, which in turn improved both the PT and PZT orientations. Both PZT (52/48) and (45/55) thin films with and without PT seed layers were deposited and examined via x-ray diffraction methods (XRD) as a function of annealing temperature. As expected, the PT seed layer provides significant improvement in the PZT {001}-texture while suppressing the {111}-texture of the PZT. Improvements in the Lotgering factor (f) were observed upon comparison of the original Ti/Pt/PZT process (f=0.66) with samples using the PT seed layer as a template, Ti/Pt/PT/PZT (f=0.87), and with films deposited onto the improved Pt electrodes, TiO2/Pt/PT/PZT (f=0.96).

The multilayers of ferroelectric (FE) Pb(Zr, Ti)O3 (PZT) and ferromagnetic (FM) CoFe2O4 (CFO) thin films with 3, 5, and 9 layers having configurations PZT/CFO (PC) and CFO/PZT (CP) were fabricated by pulsed laser deposition technique. We have investigated the effect of inter-diffusion at the interface of multilayers (MLs) and reversing the order of FE and FM layers in the multilayers configuration on the electrical/magnetic properties. The TEM of the films showed that the layer structure was not maintained and the inter-diffusion of the CFO into PZT and vice verse were observed at the interface of MLs. Both the PC and CP configurations of multilayer films exhibited pseudo FE hysteresis loop and proper FM hysteresis loops at room temperature. Reversing the multilayer configuration from CP to PC resulted in increasing the pseudo remanent polarization, however this behavior was not observed in magnetic properties. The frequency and temperature dependences of the impedance and modulus spectroscopy of the multilayer PC and CP films were studied in the ranges of 102 to 106 Hz and 200 to 650 K respectively. The electrical response of all multilayer films investigated could be resolved into two contributions. We attributed these to the grain and grain boundary effects in impedance and modulus formalism. We found that the difference between the grain and grain boundary capacitive effect decreased due to increase of the number of layers.

The linear stability of the spiral motion induced between concentric cylinders by an axial pressure gradient and independent cylinder rotation is studied numerically and experimentally for a wide-gap geometry. A three-dimensional disturbance is considered. Linear stability limits in the form of Taylor numbers TaL are computed for the rotation ratios μ, = 0, 0·2, and -0·5 and for values of the axial Reynolds number Re up to 100. Depending on the values of μ and Re, the disturbance which corresponds to TaL can have a toroidal vortex structure or a spiral form. Aluminium-flake flow visualization is used to determine conditions for the onset of a secondary motion and its structure at finite amplitude. The experimental results agree with the predicted values of TaL for μ [ges ] 0, and low Reynolds number. For other cases in which agreement is only fair, apparatus length is shown to be a contributing influence. The comparison between experimental and predicted wave forms shows good agreement in overall trends.

Extended abstract of a paper presented at Microscopy and Microanalysis 2005 in Honolulu, Hawaii, USA, July 31--August 4, 2005

Caprella wirtzi sp. nov. from the Cape Verde Islands is described. It is close to C. liparotensis a species recorded from Portugal and along the Mediterranean coasts to the Black Sea, but distinguished from C. liparotensis by the morphology of antenna 2, gnathopod 2 and peraeonites 3, 6 and 7. Variation from C. liparotensis is also discussed.

A large caprellid amphipod recently discovered at a salmon farm in the Lynne of Lorne near Oban, Scotland, has been identified as Caprella mutica, a species indigenous to north-east Asia. The caprellid population appears to have become established in the last four years at the site with a high abundance of animals occurring year round on the farm nets, mooring ropes and on artificial experimental structures located <10 m from the fish farm. This paper briefly describes C. mutica found in Scotland. Application of Chapman & Carlton's criteria for determining introduced species suggests that C. mutica is non-indigenous to the area.

In this paper we present a new method of the rapid construction of magnetic phase diagrams in a temperature-composition space, using magneto-optic imaging with an indicator film technique (MOIF). The method is applied for mapping the diagram for the La1–xCaxMnO3 colossal magneto-resistive oxide, using the spread films deposited on a SrTiO3 substrate. The constructed magnetic diagram is in a good agreement with data on uniform films and bulk crystals of this system. The MOIF study of transitions under cooling and heating has revealed the formation of a non-magnetic phase in the area of temperatures from 5 K to 57 K and compositions from x = 0 to x = 0.5.

Magnetic bilayers Fe/Sm-Co and Co/Sm-Co have been fabricated with gradient thicknesses of the soft layers in order to systematically study the dependence of exchange coupling on the thickness of the soft layer. The films were deposited in a combinatorial magnetron-sputtering chamber, where the Fe and Co thickness wedges were created by the natural thickness gradient due to the deposition geometry. The soft layer was deposited at two different temperatures (150°C and 300°C) in order to study the effect of deposition temperature on the exchange coupling. The deposition of the Fe layer at the higher temperature (300°C) was found to enhance the interlayer exchange coupling between Fe and Sm-Co. The single-phase-like magnetization reversal critical thickness increases from 12 nm for Fe deposited at 150°C to 24 nm for Fe deposited at 300°C. We attribute the enhanced exchange coupling in Fe/Sm-Co bilayers to the interfacial mixing and the coherent growth of the Fe layer. On the other hand, we found that the exchange coupling between Co and Sm-Co is not sensitive to the growth temperature of the Co layer.

High-throughput synthesis and characterization techniques have been effective in discovering new materials and performing rapid mapping of phase diagrams. The application of the combinatorial strategy to explore doped transition-metal oxides has led to the discovery of a transparent room-temperature ferromagnetic oxide in Co-doped anatase TiO2. The discovery has triggered a wave of studies into other metal oxide systems in pursuit of diluted magnetic semiconductors. In this article, we describe recent combinatorial studies of magnetic transition-metal oxides, germanium-based magnetic semiconductors, and Heusler alloys.

We have fabricated thin-film combinatorial gas sensor libraries based on doped semiconducting SnO2 thin films. The utility of combinatorial libraries is two-fold: one is to search and optimize the compositions for high sensitivity and selectivity of gases, and the other is to make use of the natural array geometry of the libraries with different sensor elements for electronic noses. Combinatorial pulsed-laser ablation was used to deposit compositionally varying arrays of sensor elements onto a pre-patterned device electrode configuration. Using a multiplexing electronics, we have demonstrated detection of chloroform, formaldehyde, and benzene gases at concentrations down to 12.5 ppm through pattern recognition of signals from the arrays of sensors.

In this paper we present the accelerated reliability testing of MgZnO based UV detectors. The UV detectors are fabricated on glass, quartz and sapphire substrates by Pulsed Laser Deposition (PLD) technique. The films are highly oriented and show sharp transmission at 350nm and 330nm for Mg composition of 10% and 20% in ZnO, respectively. The device response has been studied and life expectancy of the devices has been estimated from the accelerated tests.

Pulsed laser deposition of TiO2 and BaF2 layers at room temperature and subsequent annealing in flowing oxygen were used to form homogeneous epitaxial BaTiO3 films on LaAlO3. This oxide film synthesis method, known as the precursor technique, is frequently used for making combinatorial libraries. In this paper, we investigated the microstructures of the films at different stages of annealing using cross-sectional transmission electron microscopy, high-resolution imaging, and electron energy loss spectroscopy. It was shown that epitaxial BaTiO3 thin films with large grains could be formed on a LaAlO3 substrate. Their formation process consists of the following stages: At 200 °C, the BaF2 layer is partially oxidized. At 400 °C, the amorphous TiO2 layer crystallizes, further transformation of BaF2 into BaO takes place, and interdiffusion begins. At 700 °C, the formation of a polycrystalline structure with different Ba–Ti oxides occurs, epitaxial BaTiO3 grains nucleate on the film/substrate interface, and significant interdiffusion takes place. Finally, at 900 °C, the interdiffusion is completed, and the epitaxial BaTiO3 grains coalesce and grow. The presence of nonepitaxial polycrystalline regions in fully annealed films can be explained as the following: (i) stoichiometric transient regions not yet consumed by recrystallization of BaTiO3; (ii) nonstoichiometric regions resulting from inhomogeneous deposition of BaF2.

The observability of hydrogen molecules in absorption was investigated for infrared lines against bright infrared sources. The absorption efficiency of the hydrogen molecules becomes comparable with or larger than that of the dust grains in the metal-poor condition expected in the early Universe. If we can use bright infrared continuum sources behind the molecular gas clouds, the absorption measurement of the hydrogen molecules will be an important technique to explore the primordial gas clouds that are contracting into first-generation objects.