Doping heterogeneous

One consequence of the modified defect chemistry being restricted to the boundary is readily seen in Fig. 27. Unlike in the case of homogeneous doping, in heterogeneous doping the transition from interstitial to vacancy type does not show up as a knee in the conductivity curves, since, as soon as the boundary zone becomes less conductive, the bulk which is in parallel, dominates.113... 

Oxide admixtures also proved beneficial (see, e.g. reference116) in the case of ion conducting polymers. Even though mobility effects occur, too, the separation of an ion pair in the rather covalent matrix by adsorbing one partner is possible, an effect that can be subsumed under the phenomenon of heterogeneous doping.37... 

In situ generation of metal, metal salt and metal oxide produces materials with distributions of particles that would be difficult to achieve via heterogeneous doping. Surface metal or metal oxide coatings can also be obtained that would not result from conventional heterogeneously modified polymers. The chemistry and response of these microcomposite polymers to process conditions need to be explored further. As the structure and properties of the systems that have been herein described are better understood and new metal/polymer systems are explored, their application in electronic, adhesive and composite systems should emerge. 

Litzelman, S.J. (2008) Modification of space charge transport in nanocrystalline ceriiun oxide by heterogeneous doping. Ph.D. thesis, Massachusetts Institute... 

Modulation of mixed conductivity in nanocrystalline electrolytes by heterogeneous doping, in Electrochemical Society Transactions, Vol. 16, Solid State Ionic Devices 6 - Nano-Ionics Electrochemical Society Meeting, 12-17 October 2008, Honolulu, HI (eds E. Wachsman, J. Weidner, K. Abraham, E. Traversa, S. Yamaguchi, K. Zaghib, R. Mukundan, and S. Minteer), Electrochemical Society, pp. 3-12. 

Litzelman, S.J., De Souza, R.A., Butz, B Tuller, H.L., Martin, M and Gerthsen, D. (2008) Heterogeneously doped nanocrystaUine ceria films by grain boundary diffusion Impact on transport properties. J. Electroceram.,... 

PcFe(pyz)]p or [OEPRu(pyz)]n yields stable compounds with the stoichiometries [PcFe(pyz)Iy] (y=0-2.6) [71] and [OEPRu(pyz)Iy]n (y=0-6) respectively [89]. The doped compounds [PcFe(pyz)Iy]p are obtained either by heterogenous doping or by precipitating the polymer from a solution of PcFe(pyz)2 containing iodine. 

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