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The parameters affecting the growth of small crystallites within the anodic oxide film formed on aluminum during anodization in an 85°C aqueous ammonium dihydrogen phosphate electrolyte have been investigated. The degree of crystallinity of the anodic oxide was observed to increase with decreasing anodization current density and increasing voltage. The more crystalline films had a higher capacitance, were thinner, and contained less phosphorus than largely amorphous films anodized to the same voltage. A short thermal treatment of the aluminum foil at 600°C produced tiny platelets of γ‐Al2O3 , which acted as effective nucleation sites for the growth of crystalline anodic oxide. Nucleation of crystalline anodic oxide also occurred on electropolished foil; however, the deposition of a thin amorphous oxide film on the electropolished aluminum prevented crystal growth during subsequent anodization. The crystalline anodic oxide has the γ′‐Al2O3 crystal structure and shows a strong preferred orientation related to the orientation of the aluminum substrate. A much smaller number of crystal growth sites was observed in the anodic oxide grown on (100) aluminum grains than in the oxide grown on any other substrate orientation.

The growth of crystalline anodie aluminum oxide during anodization in an aqueous ammonium citrate electrolyte has been investigated. Crystalline sites were observed to nucleate only during the early growth of the oxide film, and their number was dependent upon the electrolyte temperature and the crystallographic orientation of the electropolished aluminum substrate. As anodization continued, the crystalline sites grew larger but did not increase in number; eventually, the individual sites grew together to form a continuous crystalline sheet. It is postulated that the initial crystalline sites grow radially outward by field-assisted transformation of the surrounding amorphous oxide into crystalline oxide. Transition layers observed between the amorphous and crystalline areas of the film are interpreted as intermediate stages of the amorphous to crystalline transformation.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.114.34.22 ABSTRACTThe development of an anodic oxide dielectric film has made possible the fabrication of mesa stripe geometry PbEuSeTe single quantum well diode lasers operating up to 174 K CW. This anodic oxide is grown electrolytically from a glycerol-rich solution of water, ethanol, and potassium hydroxide through an anodization]dissolution process. The dissolution rate is controlled by the glycerol concentration. This makes it possible to grow a relatively thick native oxide reproducibly. The oxide appears to be uniform, pinhole free, and electrically insulating. This oxide growth technique has been successfully used for dielectric passivation of mesa stripe geometry diode lasers consisting of a number of PbTe-rich alloys, such as PbSnTe, PbEuSeTe, and PbSnYbTe. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.114.34.22 Downloaded on 2015-04-02 to IP

N-Halosuccinimides and quaternary ammonium halides form both 1:1 and 2:1 complexes. Where two different halogen atoms are involved, the complex, in every case studied, has the more electronegative halogen atom associated with the quaternary ammonium ion and the less electronegative halogen atom bonded to the imide nitrogen. Where necessary a halogen interchange reaction occurs to satisfy this requirement. A mechanism for this halogen interchange reaction is proposed.

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