Dieser Aufwand wurde vollständig von der US DOE, Office of Basic Energy Sciences, Materialwissenschaften und Engineering Division unterstützt.

1. Beispiel Wachstum Fabrication <ol><li> Reinigen Sie einen 5 mm x 5 mm x 0,5 mm-Einkristall-Substrats mit einer Fehlschnittwinkels &lt;0,1 Grad wie SrTiO3 oder LaAlO 3 mit Aceton und dann mit Wasser in einem Ultraschall-Reiniger für jeweils 10 Minuten. Um eine TiO 2 Terminierung SrTiO 3, Ätzen des Substrats in 10% Fluorwasserstoff für 30 sec erhalten und Spülen in Wasser für 1 Minute, gefolgt von einer bei 1100 ° C für 10 h Temperung gefolgt. Nach der Reinigung, Montage des Substrats auf einem Heizgerät für Ultrahochvakuum-Bedingungen. </li><li> Montieren Sie die Heizung in der PLD Vakuumkammer und öffnen Sie die Kammer Sauerstoff-Quelle, um die Kammer mit 2 x 10E-5 Torr Sauerstoff zu füllen. Heben Sie die Heiztemperatur bis 800 ° C und lassen Sie es für 20 Minuten glühen. Temperatur überwacht mit Hilfe eines computergesteuerten Pyrometer oder ein Thermoelement werden. </li><li> Um Schichtabscheidung beginnen, starten die Excimer-Laser mit einem gepulsten Laser-Fluenz von 1 bis 2 J / cm 2 und Laserfrequenz von 1oder 2 Hz. Die Laserpulse treffen wird die Target-Material und erzeugen eine Wolke Fluss. Der Fluss wird durch den Sauerstoff Umwelt und Einzahlung auf das Substrat eindringen. </li><li> Reflection High Energy Electron Diffraction (RHEED) kann verwendet werden, um Einheit Zellwachstum überwachen und bestätigen Oberflächenqualität 7 werden. Diese Technik ermöglicht eine sehr klare Dicke Überwachung. </li><li> Wenn der Film mit der gewünschten Dicke ist, schalten Sie den Laser und verringern die Heiztemperatur bei 5 ° C / min. Sobald die Heizung auf Raumtemperatur abgekühlt ist, schalten Sie den Sauerstoff-Quelle und entfernen Sie die Probe. </li><li> Ex-situ-Glühung auf Oxid-Materialien verwendet werden, um Sauerstoff Mängel, die vorhanden sein können, nach dem Wachstum oder längerer im Vakuum zu entfernen. Legen Sie die Probe in einem Rohrofen unter 1 atm strömendem Sauerstoff. Erhöhen Sie die Temperatur von 20 ° C bis 700 ° C bei 5 ° C / min, 2 h Glühen, und dann sinken Temperatur von 700 ° C bis 20 ° C bei 2 ° C / min. Eine wichtige keinete ist, nie bei höheren Temperaturen als bei der Folienherstellung Wachstum beim Ausfüllen Sauerstoffleerstellen da dies nachteilig beeinflussen können Oberflächenqualität und negativ beeinflussen kann Kristallqualität Post-Glühen. </li></ol> 2. Photolithographie Fabrication <ol><li> Ultraschall reinigen die Probe in Aceton und dann mit Wasser für jeweils 10 Minuten. Ein optisches Mikroskop kann verwendet werden, um zu überprüfen, dass die Probenoberfläche sauber großer Partikel handelt. (Abbildung 2a) </li><li> Spin Mantel eine Schicht von 1 Mikron dicke Fotolack. Typische Spin Geschwindigkeit und Dauer sind rund 6.000 Umdrehungen pro Minute und 80 Sekunden, obwohl diese Zahlen abhängig von bestimmten Fotolack verwendet werden. Legen Sie die Probe auf einer Heizplatte bei 115 ° C für 2 min, um den Fotolack zu heilen. Überprüfen Sie die Qualität Fotolack unter einem optischen Mikroskop. Die Beschichtung sollte erscheinen Uniform ohne Blasenbildung. </li><li> Verwenden Sie einen Mask Aligner, die Probe unter einem vordefinierten Lithographie Maske mit UV-Licht aussetzen 9 Sek. lang mit einer Bestrahlungsdosisetwa 90 mJ / cm 2. Auch diese Zahlen werden spezifisch auf den Fotolack verwendet. Wenn ein positiver Photoresist verwendet wird, wird der Teil des Photoresist, die durch die Maske bedeckt ist keine Veränderung der chemischen Eigenschaft, während der Teil des PR, die von der Maske unbedeckt ist seine Eigenschaft zu ändern, kann und wird in der chemischen Entwickler gelöst werden. Heizen Sie den Fotolack und Probe bei 110 ° C für 80 Sek. weitere Heilung der Fotolack belichtet. </li><li> Spülen Sie die Probe in einer Entwickler-Lösung für 25-35 sec. Nehmen Sie die Probe sofort und gründlich in Wasser für 30 sec. Wenn positive Photoresist verwendet wird, wird der Teil des Photoresist von der Maske freigelegt wird weggewaschen werden, während der Teil, der abgedeckt bleibt. Beachten Sie, dass die Dauer der Entwicklungsschritt entscheidend genau zu steuern Photoresist Abmessungen und Qualität (Abbildung 2b). </li><li> Bereiten Sie eine Lösung von Kaliumiodid, Salzsäure und Wasser von 1:1:1. Verwenden Sie Kunststoff-Pinzette t spülener Probe in der Säure für ca. 10 Sekunden. Die ungeschützten Teil des dünnen Films wird weggeätzt werden. Sofort ausspülen die Probe in reinem Wasser für 60 Sekunden. Überprüfen Sie mit einem optischen Mikroskop zu sehen, ob der dünne Film hat völlig geätzt worden. Wenn nicht, fügen Sie 2 bis 3 Sekunden in der Säureätzung und sofort mit reinem Wasser abspülen, dann klicken Sie hier mit einem optischen Mikroskop. Wiederholen Sie diesen Vorgang, bis alle die ungeschützte Film weggeätzt wird. Dieser Prozess wird durch das Ätzmittel Stärke und Schichtdicke geregelt. Typische Ätzgeschwindigkeiten für viele Manganiten sind etwa 1-4 nm / Sekunde für den 01.01.01 Lösungs-Verhältnis beschrieben. </li><li> Spülen Sie die Probe in Aceton für 20 sec, um die verbleibende Fotolack entfernen. Prüfen Sie die Qualität der Probe mit Mikroskop (Abbildung 2c und 2d). </li></ol> 3. Draht-Bonding-Anschluss <ol><li> Mit einer Foto-Maske, wiederholen Sie die Schritte 2.1-2.3 oben unter Verwendung eines Lithographie-Maske, die offenen Bereiche auf den Drähten für den Kontakt verlassenPads. Dampft 5 nm Ti und 100 nm Au auf die Probe und spülen in Aceton. Dadurch wird der Fotolack und lassen Sie nur den gewünschten Kontakt Pad-Geometrie (Abbildung 3a). </li><li> Verwenden GE Lack, um die Probe auf die Probe Puck montieren. Erlauben Sie 15 min zu heilen. </li><li> Befestigen Sie die Probe Position auf Drahtbonders Bühne und verwenden den Draht Bonder zu Al-Drähte aus der Probe Puck Ti / Au Kontakte (3b) zu verbinden. Dann führen Sie elektrische Messungen. </li></ol>

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Keine Interessenskonflikte erklärt.

Anders als einzelnes Element Halbleitermaterialien wie Si, kann die Herstellung komplexer Materialien erschwert durch die Tatsache, dass die komplexe Struktur und mehrere Elemente alle berücksichtigt werden. Die Verwendung von Photolithographie, um komplexe Oxid Geräte herzustellen ist relativ kostengünstig und schnell Prototypen zu anderen Techniken gegenüberliegende Begrenzung. Es gibt jedoch einige wichtige Einschränkungen zu verstehen. Photolithographie hat eine räumliche Beschränkung auf Schaffung von Strukt...

Der erste und einer der wichtigsten Schritte zur hochwertigen Geräten ist das Wachstum der epitaktischen Oxiddünnschichten. Einkristall-Substrat als &quot;Vorlage&quot;, um die Target-Materialien abzuscheiden. Unter den verschiedenen Methoden Abscheidung ist Pulsed Laser Deposition (PLD) eine der besten Möglichkeiten, um gute Qualität Dünnschichten 4,5 erwerben. Die Wachstumsprozesse das Erhitzen des Substrats auf etwa 800 ° C in einer sauerstoffarmen Umgebung und mit Laserimpulsen, um die Target-Material getroffen und erzeugen ein Flußmittel auf das Substrat aufgebracht werden. Das typische System ist in Abbildung 1 dargestellt. Während unstrukturierten Filme gezeigt wurde, zeigen exotische neue Physik 6, wodurch Film Dimension bietet mehr Möglichkeiten, neue Phänomene und Bauelementherstellung erkunden. Photolithographie verwendet werden, um die in der Ebene Probendimensionsmessung unten verkleinert, um in der Größenordnung von 1 um. Das detaillierte Protokoll der Photolithographie-Prozess wirdnachfolgend diskutiert. Diese Technik ist kompatibel mit den meisten verbreiteten Substraten, die für Untersuchungen der Entbindung Auswirkungen auf Epitaxialfilme bei anderen Stamm Staaten gehalten werden kann. Da viele komplexe Oxide interessante Eigenschaften bei niedrigen Temperaturen und / oder hoher Magnetfelder haben, ist die elektrische Verbindung zwischen dem Gerät und Messgeräte sehr wichtig. Hochwertige Kontakte können durch Verdampfen Au Kontaktflächen in einem 4-Sonden-Geometrie und unter Verwendung eines Drahtbonders um Verbindungen zwischen den Pads und Messvorrichtung zu bilden. Wenn es richtig gemacht, können diese Verbindungen leicht widerstehen extremen Messumgebungen in weiten Temperaturbereichen von 4 K bis 400 K und Magnetfeld Reichweiten von bis zu ± 9 T.

<table border="1">
 <tbody>
 <tr>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>Reagent/Material</td>
 </tr>
 <tr>
 <td>SrTiO3(001) &amp; LaAlO3(100) substrates</td>
 <td>CrysTec GmbH</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Microposit S1813 Photoresist</td>
 <td>Shipley</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>CD-26 Developer</td>
 <td>Shipley</td>
 <td>38490</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>GE varnish</td>
 <td>Lakeshore</td>
 <td>VGE-7031</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>Equipment</td>
 </tr>
 <tr>
 <td>Reflected High Energy Electron Diffraction (RHEED)</td>
 <td>Staib Instruments</td>
 <td>&nbsp;</td>
 <td>35 kV TorrRHEED</td>
 </tr>
 <tr>
 <td>Mask Aligner</td>
 <td>ABM</td>
 <td>Model 85-3 (350 W) Lightsource</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Resistivity Puck</td>
 <td>Quantum Design</td>
 <td>P102</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Wire Bonder</td>
 <td>Kulicke &amp; Soffa</td>
 <td>04524-0XDA-000-00</td>
 <td>&nbsp;</td>
 </tr>
 </tbody>
</table>

fabrication of spatially confined complex oxides

Komplexe Materialien wie High Tc Supraleitern Multiferroika und kolossale Magnetowiderstände haben elektronische und magnetische Eigenschaften, die von den inhärenten starken elektronischen Korrelationen, die in ihnen wohnen entstehen. Diese Materialien können auch über elektronische Phasentrennung in welchen Regionen sehr unterschiedliche ohmsche und magnetische Verhalten innerhalb eines Einkristall-Legierungsmaterial koexistieren können. Eine Verringerung des Umfangs dieser Materialien Längenskala an und unterhalb der inhärenten Größe der elektronischen Domänen können neue Verhalten ausgesetzt werden. Aus diesem Grund und der Tatsache, dass Spin-Ladungs-Gitter-Orbital-Parameter um jeweils um Korrelationslängen, räumlich Reduzierung dieser Materialien für Transport-Messungen ist ein entscheidender Schritt zum Verständnis der grundlegenden Physik, die komplexe Verhaltensweisen treibt. Diese Materialien bieten auch ein großes Potenzial, um die nächste Generation von elektronischen Geräten 1-3 geworden. Somit wird die Herstellung von niederdimensionalen nano-oderMikrostrukturen ist äußerst wichtig, um neue Funktionen zu erreichen. Diese umfasst mehrere steuerbare Prozesse von hoher Qualität Dünnschicht Wachstum um genaue elektronische Eigenschaft Charakterisierung. Hier präsentieren wir Herstellung Protokolle von hoher Qualität für komplexe Mikrostrukturen Oxid Manganit Geräte. Detaillierte Beschreibungen und erforderliche Ausrüstung von Dünnschicht-Wachstum, Photolithographie und Draht-Bonding werden vorgestellt.

Dieser Beitrag konzentriert sich vor allem auf die Photolithographie und Draht-Bonding-Aspekte der Probenvorbereitung. Weitere Details auf Filmwachstum Prozeduren können in unseren anderen neueren Publikationen 8 gefunden werden. Die Photolithographie ist ein wichtiges Verfahren zur Räumlichkeit in komplexen Oxiden zur Untersuchung von Elektronenstrahlen Korrelationslängen und elektronische Phasentrennung 9-13 zu steuern. 2 zeigt optische Bilder von ...

Watch this Scientific Journal Video about Fabrication of Spatially Confined Complex Oxides at JoVE.com

Fabrication of Spatially Confined Complex Oxides

Wir beschreiben die Verwendung von Pulsed Laser Deposition (PLD), Photolithographie und Draht-Bonding-Techniken, um komplexe Oxide Mikrometerskala Geräte zu erstellen. Die PLD wird genutzt, um epitaktischen dünnen Schichten wachsen. Photolithographie und Draht-Bonding-Techniken eingeführt, um praktische Geräte zur Messung Zwecke erstellen.

Herstellung von räumlich getrennter komplexe Oxide

Complex materials such as high Tc superconductors, multiferroics, and colossal magnetoresistors have electronic and magnetic properties that arise from ...

fabrication-of-spatially-confined-complex-oxides

Research

JoVE Journal

Engineering

9.4K Aufrufe.  Oak Ridge National Laboratory. Wir beschreiben die Verwendung von Pulsed Laser Deposition (PLD), Photolithographie und Draht-Bonding-Techniken, um komplexe Oxide Mikrometerskala Geräte zu erstellen. Die PLD wird genutzt, um epitaktischen dünnen Schichten wachsen. Photolithographie und Draht-Bonding-Techniken eingeführt, um praktische Geräte zur Messung Zwecke erstellen.

Serie: Fabrication of Spatially Confined Complex Oxides

Measuring Spatially- and Directionally-varying Light Scattering from Biological Material

Light interacts with an organism's integument on a variety of spatial scales. For example in an iridescent bird: nano-scale structures produce color; the milli-scale structure of barbs and barbules largely determines the directional pattern of reflected light; and through the macro-scale spatial structure of overlapping, curved feathers, these directional effects create the visual texture. Milli-scale and macro-scale effects determine where on the organism's body, and from what viewpoints and under what illumination, the iridescent colors are seen. Thus, the highly directional flash of brilliant color from the iridescent throat of a hummingbird is inadequately explained by its nano-scale structure alone and questions remain. From a given observation point, which milli-scale elements of the feather are oriented to reflect strongly? Do some species produce broader "windows" for observation of iridescence than others? These and similar questions may be asked about any organisms that have evolved a particular surface appearance for signaling, camouflage, or other reasons.
In order to study the directional patterns of light scattering from feathers, and their relationship to the bird's milli-scale morphology, we developed a protocol for measuring light scattered from biological materials using many high-resolution photographs taken with varying illumination and viewing directions. Since we measure scattered light as a function of direction, we can observe the characteristic features in the directional distribution of light scattered from that particular feather, and because barbs and barbules are resolved in our images, we can clearly attribute the directional features to these different milli-scale structures. Keeping the specimen intact preserves the gross-scale scattering behavior seen in nature. The method described here presents a generalized protocol for analyzing spatially- and directionally-varying light scattering from complex biological materials at multiple structural scales.

We present a non-destructive method for sampling spatial variation in the direction of light scattered from structurally complex materials. By keeping the material intact, we preserve gross-scale scattering behavior, while concurrently capturing fine-scale directional contributions with high-resolution imaging. Results are visualized in software at biologically-relevant positions and scales.

Mess-und Richtungs räumlich variierenden Lichtstreuung aus biologischem Material

Light interacts with an organism's integument on a variety of spatial scales. For example in an iridescent bird: nano-scale structures produce color; the ...

Forschung

Ingenieurwesen

Fabrication of Nano-engineered Transparent Conducting Oxides by Pulsed Laser Deposition

Nanosecond Pulsed Laser Deposition (PLD) in the presence of a background gas allows the deposition of metal oxides with tunable morphology, structure, density and stoichiometry by a proper control of the plasma plume expansion dynamics. Such versatility can be exploited to produce nanostructured films from compact and dense to nanoporous characterized by a hierarchical assembly of nano-sized clusters. In particular we describe the detailed methodology to fabricate two types of Al-doped ZnO (AZO) films as transparent electrodes in photovoltaic devices: 1) at low O2 pressure, compact films with electrical conductivity and optical transparency close to the state of the art transparent conducting oxides (TCO) can be deposited at room temperature, to be compatible with thermally sensitive materials such as polymers used in organic photovoltaics (OPVs); 2) highly light scattering hierarchical structures resembling a forest of nano-trees are produced at higher pressures. Such structures show high Haze factor (&gt;80%) and may be exploited to enhance the light trapping capability. The method here described for AZO films can be applied to other metal oxides relevant for technological applications such as TiO2, Al2O3, WO3 and Ag4O4.

We describe the experimental method to deposit nanostructured oxide thin films by nanosecond Pulsed Laser Deposition (PLD) in the presence of a background gas. By using this method Al-doped ZnO (AZO) films, from compact to hierarchically structured as nano-tree forests, can be deposited.

Herstellung von transparenten leitenden Oxide durch Pulsed Laser Deposition Nano-engineered

Nanosecond Pulsed  Laser Deposition (PLD) in the presence of a background gas allows the deposition  of metal oxides with tunable morphology, structure, ...

Experimental Measurement of Settling Velocity of Spherical Particles in Unconfined and Confined Surfactant-based Shear Thinning Viscoelastic Fluids

An experimental study is performed to measure the terminal settling velocities of spherical particles in surfactant based shear thinning viscoelastic (VES) fluids. The measurements are made for particles settling in unbounded fluids&#160;and fluids between parallel walls. VES fluids over a wide range of rheological properties are prepared and rheologically characterized. The rheological characterization involves steady shear-viscosity and dynamic oscillatory-shear measurements to quantify the viscous and elastic properties respectively. The settling velocities under unbounded conditions are measured in beakers having diameters at least 25x the diameter of particles. For measuring settling velocities between parallel walls, two experimental cells with different wall spacing are constructed. Spherical particles of varying sizes are gently dropped in the fluids and allowed to settle. The process is recorded with a high resolution video camera and the trajectory of the particle is recorded using image analysis software. Terminal settling velocities are calculated from the data.
The impact of elasticity on settling velocity in unbounded fluids is quantified by comparing the experimental settling velocity to the settling velocity calculated by the inelastic drag predictions of Renaud et al.1&#160;Results show that elasticity of fluids can increase or decrease the settling velocity. The magnitude of reduction/increase is a function of the rheological properties of the fluids and properties of particles. Confining walls are observed to cause a retardation effect on settling and the retardation is measured in terms of wall factors.

This paper demonstrates the experimental procedure to measure terminal settling velocities of spherical particles in surfactant-based shear thinning viscoelastic fluids. Fluids over a wide range of rheological properties are prepared and settling velocities are measured for a range of particle sizes in unbounded fluids and fluids between parallel walls.

Experimentelle Messung der Settling Velocity von sphärischen Partikeln in unbeschränkten und geschlossenen Tensid-basierten Scherdünnungsviskoelastischen Flüssigkeiten

An experimental study is performed to measure the terminal settling velocities of spherical particles in surfactant based shear thinning viscoelastic ...

Fabrication and Testing of Microfluidic Optomechanical Oscillators

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including microresonators. However, because of the increased acoustic radiative losses during direct liquid immersion of optomechanical devices, almost all published optomechanical experiments have been performed in solid phase. This paper discusses a recently introduced hollow microfluidic optomechanical resonator. Detailed methodology is provided to fabricate these ultra-high-Q microfluidic resonators, perform optomechanical testing, and measure radiation pressure-driven breathing mode and SBS-driven whispering gallery mode parametric vibrations. By confining liquids inside the capillary resonator, high mechanical- and optical- quality factors are simultaneously maintained.

Parametric optomechanical excitations have recently been experimentally demonstrated in microfluidic optomechanical resonators by means of optical radiation pressure and stimulated Brillouin scattering. This paper describes the fabrication of these microfluidic resonators along with methodologies for generating and verifying optomechanical oscillations.

Herstellung und Prüfung von Mikrofluidik-Optomechanische Oszillatoren

Cavity optomechanics experiments that parametrically couple the phonon modes and photon modes have been investigated in various optical systems including ...

Atomically Traceable Nanostructure Fabrication

Reducing the scale of etched nanostructures below the 10 nm range eventually will require an atomic scale understanding of the entire fabrication process being used in order to maintain exquisite control over both feature size and feature density. Here, we demonstrate a method for tracking atomically resolved and controlled structures from initial template definition through final nanostructure metrology, opening up a pathway for top-down atomic control over nanofabrication. Hydrogen depassivation lithography is the first step of the nanoscale fabrication process followed by selective atomic layer deposition of up to 2.8 nm of titania to make a nanoscale etch mask. Contrast with the background is shown, indicating different mechanisms for growth on the desired patterns and on the H passivated background. The patterns are then transferred into the bulk using reactive ion etching to form 20 nm tall nanostructures with linewidths down to ~6 nm. To illustrate the limitations of this process, arrays of holes and lines are fabricated. The various nanofabrication process steps are performed at disparate locations, so process integration is discussed. Related issues are discussed including using fiducial marks for finding nanostructures on a macroscopic sample and protecting the chemically reactive patterned Si(100)-H surface against degradation due to atmospheric exposure.

We report a protocol for combining the atomic metrology of the Scanning Tunneling Microscope for surface patterning with selective Atomic Layer Deposition and Reactive Ion Etching. Using a robust process involving numerous atmospheric exposures and transport, 3D nanostructures with atomic metrology are fabricated.

Atomar Traceable Nanostrukturen

Reducing the scale of etched nanostructures below the 10 nm range eventually will require an atomic scale understanding of the entire fabrication process ...

Fabrication and Characterization of Superconducting Resonators

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors (MKIDs) for the detection of faint astrophysical signatures, as well as for quantum computing applications and materials characterization. In this paper, procedures are presented for the fabrication and characterization of thin-film superconducting microwave resonators. The fabrication methodology allows for the realization of superconducting transmission-line resonators with features on both sides of an atomically smooth single-crystal silicon dielectric. This work describes the procedure for the installation of resonator devices into a cryogenic microwave testbed and for cool-down below the superconducting transition temperature. The set-up of the cryogenic microwave testbed allows one to do careful measurements of the complex microwave transmission of these resonator devices, enabling the extraction of the properties of the superconducting lines and dielectric substrate (e.g., internal quality factors, loss and kinetic inductance fractions), which are important for device design and performance.

Superconducting microwave resonators are of interest for detection of light, quantum computing applications and materials characterization. This work presents a detailed procedure for fabrication and characterization of superconducting microwave resonator scattering parameters.

Herstellung und Charakterisierung von Superconducting Resonators

Superconducting microwave resonators are of interest for a wide range of applications, including for their use as microwave kinetic inductance detectors ...

Fabrication of Periodic Gold Nanocup Arrays Using Colloidal Lithography

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing in combination with new nanofabrication techniques. A plasmon is a quantum of charge density oscillation that lends nanoscale metals such as gold and silver unique optical properties. In particular, gold and silver nanoparticles exhibit localized surface plasmon resonances-collective charge density oscillations on the surface of the nanoparticle-in the visible spectrum. Here, we focus on the fabrication of periodic arrays of anisotropic plasmonic nanostructures. These half-shell (or nanocup) structures can exhibit additional unique light-bending and polarization-dependent optical properties that simple isotropic nanostructures cannot. Researchers are interested in the fabrication of periodic arrays of nanocups for a wide variety of applications such as low-cost optical devices, surface-enhanced Raman scattering, and tamper indication. We present a scalable technique based on colloidal lithography in which it is possible to easily fabricate large periodic arrays of nanocups using spin-coating and self-assembled commercially available polymeric nanospheres. Electron microscopy and optical spectroscopy from the visible to near-infrared (near-IR) was performed to confirm successful nanocup fabrication. We conclude with a demonstration of the transfer of nanocups to a flexible, conformal adhesive film.

We demonstrate the fabrication of periodic gold nanocup arrays using colloidal lithographic techniques and discuss the importance of nanoplasmonic films.

Herstellung von periodischen Gold Nanocup Arrays mit kolloidalen Lithographie

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing ...

Simultaneous Multi-surface Anodizations and Stair-like Reverse Biases Detachment of Anodic Aluminum Oxides in Sulfuric and Oxalic Acid Electrolyte

After reporting on the two-step anodization, nanoporous anodic aluminum oxides (AAOs) have been widely utilized in the versatile fields of fundamental sciences and industrial applications owing to their periodic arrangement of nanopores with relatively high aspect ratio. However, the techniques reported so far, which could be only valid for mono-surface anodization, show critical disadvantages, i.e., time-consuming as well as complicated procedures, requiring toxic chemicals, and wasting valuable natural resources. In this paper, we demonstrate a facile, efficient, and environmentally clean method to fabricate nanoporous AAOs in sulfuric and oxalic acid electrolytes, which can overcome the limitations that result from conventional AAO fabricating methods. First, plural AAOs are produced at one time through simultaneous multi-surfaces anodization (SMSA), indicating mass-producibility of the AAOs with comparable qualities. Second, those AAOs can be separated from the aluminum (Al) substrate by applying stair-like reverse biases (SRBs) in the same electrolyte used for the SMSAs, implying simplicity and green technological characteristics. Finally, a unit sequence consisting of the SMSAs sequentially combined with SRBs-based detachment can be applied repeatedly to the same Al substrate, which reinforces the advantages of this strategy and also guarantees the efficient usage of natural resources.

A protocol for fabricating nanoporous anodic aluminum oxides via simultaneous multi-surfaces anodization followed by stair-like reverse biases detachments is presented. It can be applied repeatedly to the same aluminum substrate, exhibiting a facile, high-yield, and environmentally clean strategy.

Gleichzeitige Multi-Oberfläche Anodizations und Treppe-wie umgekehrte Vorurteile Ablösung der anodische Aluminium Oxide in Schwefelsäure und Oxalsäure-Elektrolyten

After reporting on the two-step anodization, nanoporous anodic aluminum oxides (AAOs) have been widely utilized in the versatile fields of fundamental ...

Fabrication of Superhydrophobic Metal Surfaces for Anti-Icing Applications

Several ways to produce superhydrophobic metal surfaces are presented in this work. Aluminum was chosen as the metal substrate due to its wide use in industry. The wettability of the produced surface was analyzed by bouncing drop experiments and the topography was analyzed by confocal microscopy. In addition, we show various methodologies to measure its durability and anti-icing properties. Superhydrophobic surfaces hold a special texture that must be preserved to keep their water-repellency. To fabricate durable surfaces, we followed two strategies to incorporate a resistant texture. The first strategy is a direct incorporation of roughness to the metal substrate by acid etching. After this surface texturization, the surface energy was decreased by silanization or fluoropolymer deposition. The second strategy is the growth of a ceria layer (after surface texturization) that should enhance the surface hardness and corrosion resistance. The surface energy was decreased with a stearic acid film.
The durability of the superhydrophobic surfaces was examined by a particle impact test, mechanical wear by lateral abrasion, and UV-ozone resistance. The anti-icing properties were explored by studying the ability to repeal subcooled water, freezing delay, and ice adhesion.

We illustrate several methodologies to produce superhydrophobic metal surfaces and to explore their durability and anti-icing properties.

Herstellung von Superhydrophob Metalloberflächen für Anti-Icing-Anwendungen

Several ways to produce superhydrophobic metal surfaces are presented in this work. Aluminum was chosen as the metal substrate due to its wide use in ...

Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides

Here, we present a procedure for the synthesis of bulk and thin film multicomponent (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O (Co variant) and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O (Cu variant) entropy-stabilized oxides. Phase pure and chemically homogeneous (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O (x = 0.20, 0.27, 0.33) and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O (x = 0.11, 0.27) ceramic pellets are synthesized and used in the deposition of ultra-high quality, phase pure, single crystalline thin films of the target stoichiometry. A detailed methodology for the deposition of smooth, chemically homogeneous, entropy-stabilized oxide thin films by pulsed laser deposition on (001)-oriented MgO substrates is described. The phase and crystallinity of bulk and thin film materials are confirmed using X-ray diffraction. Composition and chemical homogeneity are confirmed by X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. The surface topography of thin films is measured with scanning probe microscopy. The synthesis of high quality, single crystalline, entropy-stabilized oxide thin films enables the study of interface, size, strain, and disorder effects on the properties in this new class of highly disordered oxide materials.

The synthesis of high quality bulk and thin film (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O entropy-stabilized oxides is presented.

Bulk- und Dünnschicht-Synthese von kompositorisch Variante Entropie-stabilisierten Oxide

Here, we present a procedure for the synthesis of bulk and thin film multicomponent (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O (Co variant) and ...