Characterization of nanopores arrangement of anodic alumina layers synthesized on low-(AA1050) and high-purity aluminum by two-step anodizing in sulfuric acid with addition of ethylene glycol at low temperature

ABSTRACTWe investigate implantation of high purity HVPE GaN with Mg, Be, C, Zn, Cd, Ca, N, O, P, As, Ne, and Ar. After annealing at 1300 °C, the material is characterized using low temperature photoluminescence (PL). The Mg acceptors exhibit much better optical activation than Be, C, Zn, Cd, or Ca acceptors implanted and annealed under the same conditions. Acceptor-bound exciton peaks and well-resolved donor-acceptor pair bands are observed for both Mg and Zn. A broad peak centered near 2.78 eV is obtained for Cd, confirming that it is deeper than Zn. Isoelectronic As or P exhibit sharp no-phonon bound exciton lines at 2.952 and 3.200 eV, respectively. Defect-related bands centered at 2.2 and 2.35 eV are studied. Both Be and C strongly enhance the yellow (2.2 eV) PL band, but no other impurities do so, including O.

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Ionic polymerization of mono-olefinic hydrocarbons at low temperature. Characterization of the alpha-methylstyrene–sulfuric acid system

Journal of Polymer Science ◽

10.1002/pol.1951.120060203 ◽

1951 ◽

Vol 6 (2) ◽

pp. 155-164 ◽

Cited By ~ 11

Author(s):

Randall G. Heiligmann

Keyword(s):

Sulfuric Acid ◽

Low Temperature ◽

Acid System

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EBSD and TEM Characterization of Ultrafine Grained High Purity Aluminum Produced by Accumulative Roll-Bonding

Materials Science Forum ◽

10.4028/www.scientific.net/msf.512.91 ◽

2006 ◽

Vol 512 ◽

pp. 91-96 ◽

Cited By ~ 6

Author(s):

Naoya Kamikawa ◽

X. Huang ◽

Nobuhiro Tsuji ◽

Niels Hansen ◽

Yoritoshi Minamino

Keyword(s):

Misorientation Angle ◽

High Purity ◽

Accumulative Roll Bonding ◽

Structural Parameters ◽

Rolling Direction ◽

Structural Features ◽

High Angle ◽

Roll Bonding ◽

High Purity Aluminum

High purity aluminum (99.99% purity) was severely deformed by accumulative roll-bonding (ARB) to a thickness reduction of 98.4%. Quantitative microstructural characterization of the deformed sample was carried out by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). EBSD scans at various locations from the sample surface to the mid-thickness revealed a fairly uniform and equiaxed structure, although a small fraction of an elongated structure parallel to rolling direction (RD) was also observed. Misorientation angle distributions for grain boundaries of which misorientation angle was larger than 2° were evaluated by EBSD, showing that more than 70% of the boundaries were high-angle ones (>15°). More detailed structural features, such as low-angle boundaries (<2°) and dislocations between boundaries were characterized by TEM. The TEM results indicated that about 17% of the boundaries have misorientations <2° and that the fraction of high-angle boundaries is about 52%. An estimated yield strength based on the structural parameters determined by TEM was in good agreement with the measured value.

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The Synthesis and Characterization of Anodic Alumina Oxide Using Sulfuric Acid and Oxalic Acid

Nano Hybrids and Composites ◽

10.4028/www.scientific.net/nhc.31.35 ◽

2021 ◽

Vol 31 ◽

pp. 35-44

Author(s):

Nur Afieqah Md. Ghazazi ◽

Syahida Suhaimi ◽

Muhammad Zamir Othman

Keyword(s):

Sulfuric Acid ◽

Oxalic Acid ◽

Morphological Structure ◽

Anodic Alumina ◽

Electrochemical Anodization ◽

Anodic Alumina Oxide ◽

Alumina Oxide ◽

Average Size ◽

Two Parameters

Anodic Alumina Oxide (AAO) is one of the nanomaterials that have developed as a template in the nanowires, nanodots and nanotubes. This research focuses on synthesizing AAO by two different electrolytic solutions which are using sulfuric acid (H2SO4) and oxalic acid (C2H2O4) by electrochemical anodization method. Two parameters were influencing the anodization process in the experiment; the type and the concentration of the electrolytic solution. The effects of the different type of electrolytic solutions produced different size of pores. When the voltage used is 25 V in H2SO4, the optimum reading size of the nanopores is in the range of 16-22 nm, whereas the AAO pores in C2H2O4 are in the range of 100-200 nm. Meanwhile, the concentration of H2SO4 and C2H2O4 is set to be 0.3 M, 0.4 M and 0.5 M., The results in 0.3 M H2SO4 and C2H2O4, show the optimum concentration of electrolytic solutions which is the key parameter affecting the morphological structure of porous membranes in AAO. The optimum value for these two acidic solutions has produced such highly ordered arrangement of nanopores which are from the average size of nanopores that anodized in sulfuric acid is 19 nm while 120 nm in oxalic acid. The morphological structure properties of AAO templates include the diameter of nanopores, the thickness of membrane and density of nanopores would be examined by Field Emission Scanning Electron Microscope (FESEM) and Energy Dispersive X-ray (EDX). Also, Fourier-transmittance infrared spectroscopy (FTIR) detected the chemical functional group of bonds in AAO. In conclusion, AAO templates have a big potential to be the major contributor in the future for the development of new electronic devices.

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THE EFFECT OF HEAT TREATMENT ON LOW TEMPERATURE INTERNAL FRICTION MAXIMA

Canadian Journal of Physics ◽

10.1139/p58-008 ◽

1958 ◽

Vol 36 (1) ◽

pp. 82-87 ◽

Cited By ~ 7

Author(s):

T. S. Hutchison ◽

G. J. Hutton

Keyword(s):

Heat Treatment ◽

Plastic Deformation ◽

Melting Point ◽

Low Temperature ◽

Internal Friction ◽

High Purity ◽

Temperature Relation ◽

Temperature Range ◽

High Purity Aluminum

Measurements of the attenuation of sound at a frequency of 5 megacycles have been made over the temperature range 100° to 200 ° K. on polycrystalline high purity aluminum subjected to various thermal and mechanical treatments. With samples annealed at 520 °C. a maximum in the attenuation versus temperature relation had been observed at 155 ° K. This maximum was greatly increased by small amounts of plastic deformation of the order of 1.0 to 1.5%.Aluminum initially annealed for extended periods at temperatures much closer to the melting point shows, however, either no increase in the attenuation maximum at 155 ° K. or, in extreme cases, no maximum in this region at all, after plastic deformation of the same order as before. It is believed that this indicates a dependence of the deformation-induced maximum on the distribution and possibly on the number of dislocations in the metal prior to deformation and on the arrangement of the dislocations after deformation.

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