Electrodeposition phosphorous acid

Summary. An STM study has been initiated to investigate the various processes associated with electrodeposition of Cu-Ni multilayers on Cu(100). The substrates were prepared by electropolishing in phosphoric acid followed by immersion in 10 mmol/1 HCl. A (V2 x V2)R45° adlattice of oxidatively adsorbed chlorine is formed under these conditions. The adlayer stabilizes the surface steps in the <100> direction which corresponds to the close packed direction of the chloride adlattice. In dilute (millimolar) solutions of cuprous ion, reduction occurs under mass transport control with the electrocrystallization reaction proceeding by step flow in the <100> direction. At more negative potentials chloride is partially desorbed. Coincidentally, the highly kinked metal steps become Mzzy and move towards adopting the close-packed <110> orientation of the metal lattice. Preliminary experiments on heteroepitaxial nickel deposition reveal regions where electrocrystallization on Cu(100) occurs via step flow in the <110> direction. 

The synthesis of these polymers is carried out using standard methods, and is described in detail elsewhere [6]. In order for a polymer to be electrodepositable, it must contain a distribution of ionizable groups along its molecular chain. Polymers may be cationic, containing basic sites such as amino groups, or they may be anionic, containing acidic sites such as carboxylic, sulphonic or phosphoric acid groups. 

Recently, the electrodeposition of amorphous silicon was achieved using EG and FA/EG solutions of HF and tetraethyl orthosilicate or silicic acid as the silicon sources The conductivity changes from p- to n-type, when doping with phosphorous. This is possible by the addition of triethyl phosphate to an EG solution of HF containing 10 M tetraethyl orthosilicate... 

Semiconducting nanowires, nanorods, nanodots, nanocones, nanopins, etc. are interesting due to their broad range of applications. Electrochemically, the most easily fabricated semiconductors are Il-Vl semiconductors, for example, CdS, CdSe. There are three approaches for electrodeposition of semiconductors. The first method [131] is deposition of metal in alumina nanopores, followed by etching of alumina surface by phosphoric/chromic acid to access metallic surface for sulphur or arsenic vapour to attain metal sulphide or arsenide nanostructures. The second method deals with electrolysis of sulphuric acid, causing the sulphide atoms to be deposited in pores. 

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