Interfacial morphology of low-voltage anodic aluminium oxide

2013 ◽  
Vol 46 (5) ◽  
pp. 1386-1396 ◽  
Author(s):  
Naiping Hu ◽  
Xuecheng Dong ◽  
Xueying He ◽  
Sandip Argekar ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Low Voltage ◽  
Scattering Length ◽  
Aluminium Oxide ◽  
Current Control ◽  
Native Oxide ◽  
Pure Aluminium ◽  
Constant Voltage ◽  
X Ray ◽  
Film Density ◽  
Anodic Aluminium Oxide

X-ray reflectivity (XRR) and neutron reflectivity (NR), as well as ultra-small-angle X-ray scattering (USAXS), are used to examine the in-plane and surface-normal structure of anodic films formed on aluminium alloy AA2024 and pure aluminium. Aluminium and alloy films up to 3500 Å thick were deposited on Si wafers by electron beam evaporation of ingots. Porous anodic aluminium oxide (AAO) films are formed by polarizing at constant voltage up to 20 V noble to the open circuit potential. The voltage sweet spot (5 V) appropriate for constant-voltage anodization of such thin films was determined for both alloy and pure Al. In addition, a new concurrent voltage- and current-control protocol was developed to prepare films with larger pores (voltages higher than 5 V), but formed at a controlled current so that pore growth is slow enough to avoid stripping the aluminium substrate layer. USAXS shows that the pore size and interpore spacing are fixed in the first 10 s after initiation of anodization. Pores then grow linearly in time, at constant radius and interpore spacing. Using a combination of XRR and NR, the film density and degree of hydration of the films were determined from the ratio of scattering length densities. Assuming a chemical formula Al2O3·xH2O, it was found thatxvaries from 0.29 for the native oxide to 1.29 for AAO grown at 20 V under concurrent voltage and current control. The average AAO film density of the porous film at the air surface is 2.45 (20) g cm−3. The density of the `barrier' layer at the metal interface is 2.9 (4) g cm−3, which indicates that this layer is also quite porous.

A new approach to nickel electrolytic colouring of anodised aluminium

2009 ◽  
Vol 63 (1) ◽  
Author(s):  
Matilda Zemanová ◽  
Marta Chovancová ◽  
Pavol Krivošík
Keyword(s):  
Aluminium Oxide ◽  
Anodic Process ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Nickel Deposition ◽  
New Approach ◽  
X Ray ◽  
Anodic Aluminium Oxide ◽  
Anodised Aluminium ◽  
Off Time

AbstractEnergy dispersive X-ray spectroscopy and scanning electron microscopy were used to analyse nickel on anodic aluminium surfaces after stripping the anodic aluminium oxide. The metal was electroplated at the bottom of the pores of anodised aluminium during electrolytic colouring in solutions without (Watts) and with (citrate) complexing agents, respectively. A relation between the anodic-cathodic processes, changes of the structure and composition of the coating in dependence on the used solution were studied. A morphology study performed after stripping the anodic aluminium oxide revealed the crucial influence of the anodic process/cycle and the complexing agent on the nickel structure on the aluminium surface. Off-time of half-way rectified current influenced the nickel deposition in the pores of anodic alumina negatively.

INFLUENCE OF NANOWIRE DIAMETER ON STRUCTURAL AND OPTICAL PROPERTIES OF Cu NANOWIRE SYNTHESIZED IN ANODIC ALUMINIUM OXIDE FILM

2016 ◽  
Vol 23 (01) ◽  
pp. 1550093 ◽  
Author(s):  
A. CETINEL ◽  
Z. ÖZCELIK
Keyword(s):  
Aluminium Oxide ◽  
Sem Analysis ◽  
Optical Measurements ◽  
X Ray Diffraction ◽  
Nanowire Diameter ◽  
X Ray ◽  
Cu Nanowires ◽  
Anodic Aluminium Oxide ◽  
Aluminium Oxide Film

Copper (Cu) nanowire arrays embedded in anodic aluminium oxide films (AAO) on aluminium substrate have been synthesized by alternating current electrochemical deposition. Two-step anodization process has been performed to get the through-hole AAO with ordered nanochannels in 0.3[Formula: see text]M oxalic acids at DC voltages 30, 40, 50 and 60[Formula: see text]V, respectively. Structural characterization of the Cu nanowires has been analyzed by scanning electron microscopy (SEM) and X-ray diffraction (or) X-ray diffractometer (XRD). Our SEM analysis has revealed that the diameters of vertically oriented Cu nanowires are 15, 25, 45 and 60[Formula: see text]nm and the length of Cu nanowires having high packing density is about 15[Formula: see text][Formula: see text]m. XRD measurement has indicated that polycrystalline Cu nanowires prefer growth orientation along the (111) direction. Optical measurements show that reflection of the Cu nanowires/AAO on aluminium reduces with decreasing diameter of the Cu nanowires. This effect can be associated with increased light scattering from metal nanoparticles near their localized plasmon resonance frequency depending on the size and shape of the nanoparticles.

Nanoscale carbon tubules deposited in anodic aluminium oxide template: a study of soft x-ray transmission

2004 ◽  
Vol 13 (11) ◽  
pp. 1922-1926 ◽  
Author(s):  
Liu Li-Feng ◽  
Zhou Wei-Ya ◽  
Zhu Pei-Ping ◽  
Cui Ming-Qi ◽  
Zheng Lei ◽  
...  
Keyword(s):  
Aluminium Oxide ◽  
X Ray ◽  
Anodic Aluminium Oxide ◽  
Anodic Aluminium Oxide Template

Low-voltage EDS of magnesium ferrite Dendrites in a FEG-SEM

1996 ◽  
Vol 54 ◽  
pp. 478-479
Author(s):  
Matthew T. Johnson ◽  
Ian M. Anderson ◽  
Jim Bentley ◽  
C. Barry Carter
Keyword(s):  
Monte Carlo ◽  
Quantitative Analysis ◽  
Monte Carlo Simulations ◽  
Cross Section ◽  
Spatial Resolution ◽  
Low Voltage ◽  
Magnesium Ferrite ◽  
X Ray ◽  
Interaction Volume ◽  
Ferrite Spinel

Energy-dispersive X-ray spectrometry (EDS) performed at low (≤ 5 kV) accelerating voltages in the SEM has the potential for providing quantitative microanalytical information with a spatial resolution of ∼100 nm. In the present work, EDS analyses were performed on magnesium ferrite spinel [(MgxFe1−x)Fe2O4] dendrites embedded in a MgO matrix, as shown in Fig. 1. spatial resolution of X-ray microanalysis at conventional accelerating voltages is insufficient for the quantitative analysis of these dendrites, which have widths of the order of a few hundred nanometers, without deconvolution of contributions from the MgO matrix. However, Monte Carlo simulations indicate that the interaction volume for MgFe2O4 is ∼150 nm at 3 kV accelerating voltage and therefore sufficient to analyze the dendrites without matrix contributions.Single-crystal {001}-oriented MgO was reacted with hematite (Fe2O3) powder for 6 h at 1450°C in air and furnace cooled. The specimen was then cleaved to expose a clean cross-section suitable for microanalysis.

scholarly journals Great advantages of using low voltage HR-SEM in spatial resolution and sensitivity for low energy X-ray analyses

2016 ◽  
pp. 913-914
Author(s):  
Asahina Shunsuke ◽  
Takahashi Hideyuki ◽  
Takakura Masaru ◽  
Ferdi Schüth ◽  
Terasaki Osamu
Keyword(s):  
Spatial Resolution ◽  
Low Voltage ◽  
Low Energy ◽  
X Ray

scholarly journals Low Voltage Scanning Electron Microscopy

2002 ◽  
Vol 10 (2) ◽  
pp. 22-23 ◽  
Author(s):  
David C Joy ◽  
Dale E Newbury
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Spatial Resolution ◽  
Low Voltage ◽  
Incident Beam ◽  
Operational Mode ◽  
X Ray ◽  
Rapid Fall ◽  
Voltage Scanning ◽  
Scanning Electron

Low Voltage Scanning Electron Microscopy (LVSEM), defined as operation in the energy range below 5 keV, has become perhaps the most important single operational mode of the SEM. This is because the LVSEM offers advantages in the imaging of surfaces, in the observation of poorly conducting and insulating materials, and for high spatial resolution X-ray microanalysis. These benefits all occur because a reduction in the energy Eo of the incident beam leads to a rapid fall in the range R of the electrons since R ∼k.E01.66. The reduction in the penetration of the beam has important consequences.

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