Doping surface segregation

Experimentally, surface-segregation effects were shown by Ghosal et al. (2000) who studied the surfaces of bromine-doped NaCl solids (the Br/Cl ratio was 33 times higher than that of seawater) by X-ray photoelectron spectroscopy. They found that bromine was predominantly present at the surface. Zangmeister et al. (2001) confirmed this result by using a variety of experimental techniques and a range of Br/Cl ratios that covers that of seawater. However, both experiments were performed on solid salts. 

Ghosal S., Shbeeb A., and Hemminger J. C. (2000) Surface Segregation of Bromine doped NaCl implications for the seasonal variations in Arctic ozone. Geophys. Res. Lett. 27, 1879-1882. 

Szezuka, D.,Werner, X, Oswald, S., Behr, G. and Wetzing, K. (2001) XPS investigations of surface segregation of doping elements in SnOf, Appl. Surf Sci., 179, 301-6. 

Spanos, C. G. Ebbens, S. J. Badyal, J. P. S., Surface Segregation and Plasma Oxidation of Poly(dimethylsiloxane)-Doped Polyolefins. Macromolecules 2001, 34, 8149-8155. 

Femandez-Serra MV, Adessi C, Blase X (2006) Surface segregation and backscattering in doped silicon nanowires. Phys Rev Lett 96 166805... 

Nishibori M, Shin W, Tajima K, Houlet LF, Izu N, Itoh T, Matsubara I (2008) Long-term stability of Pt/alumina catalyst combustors for micro-gas sensor application. J Eur Ceram Soc 28 2183-2190 Nowotny J (1988) Surface segregation of defects in oxide ceramic materials. Solid State Ion 28-30 1235-1243 Oudet F, Vejux A, Courtine P (1989) Evolution during thermal treatment of pure and lanthanum-doped Pt/Al O, and Pt-Rh/AljO, automotive exhaust catalysts transmission electron microscopy studies on model samples. Appl Catal 50 79-86... 

Zhang Y, Duan Z, Xiao C, Wang G (2011) Density functional theory calculation of platinum surface segregation energy in PtsNi (111) surface doped with a third transition metal. Surf Sei 605 1577-1582... 

Meyer R, Waser R, Hehnbold J, Borchardt G (2002) Cationic surface segregation in donor-doped SrTiOs under oxidizing conditions. J Electroceram 9 101-110... 

A poly(styrenesulfonate)-doped poly(3,4-ethylenedioxythiophene) (PEDOT-PSS) film, which had been spun-cast from a water suspension, was used in a certain polymer-emitting diode device configuration. The results of the measurements performed on this sample, combined with those of the studies outlined above, have indicated that several important parameters can affect device performance. PSS surface segregation has been identified, with phase segregation occurring on a single grain of PEDOT-PSS [56]. 

A modification of the pseudo-sol-gel method based on the thermal decomposition of metallic propionates, was used to synthesize ceria oxides doped with 10 mol% of Zr, Zn, and Fe. Briefly, calculated amounts of Ge(lll) acetate, Zr(lV), Zn(ll), and Fe(III) acetyl acetonates were dissolved in propionic acid. After mixing by stirring, the propionic acid excess was evaporated until a kind of resin was obtained that was calcined at 500 °G for 2h. The formation of a solid solution was observed after doping with Zr and Fe, and there was ZnO surface segregation with Zn. It is interesting to consider the differing effects of the dopants. Doping with Zr enhances the... 

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