Solid-state ionic materials

Watanabe, M. In Solid State Ionics Materials and Applications-, Chowdari, B. V. R., Ed. World Scientific Publishing Co. Singapore, 1992 p 149. 

A defining feature of the models discussed in the previous section, regardless of whether they are implemented via matrix inversion, iterative techniques, or predictive methods, is that they all treat the polarization response in each polarizable center using point dipoles. An alternative approach is to model the polarizable centers using dipoles of finite length, represented by a pair of point charges. A variety of different models of polarizability have used this approach, but especially noteworthy are the shell models frequently used in simulations of solid-state ionic materials. 

In the shell model, as mentioned above, the short-range repulsion and van der Waals interactions are taken to act between the shell particles. This finding has the effect of coupling the electrostatic and steric interactions in the system in a solid-state system where the nuclei are fixed at the lattice positions, polarization can occur not only from the electric field generated by neighboring atoms, but also from the short-range interactions with close neighbors (as, e.g., in the case of defects, substitutions, or surfaces). This ability to model both electrical and mechanical polarizability is one reason for the success of shell models in solid-state ionic materials. 

In spite of the great promise solid state ionic devices offer, few commercial successes have been reported to date. The major problems faced today in the field of solid state ionic devices are still material related. At present, the key technical challenge is development of reliable and cost-efficient techniques to synthesize solid state ionic materials to serve as solid electrodes and electrolytes. On the other hand, these materials are not used in isolation, but in an electrochemical system and must be in contact with each other. The response of solid state ionic materials in solid state ionic devices is highly... 

According to the previous discussion, a PEVD process relies on mass and charge transport in two solid state ionic materials of a PEVD system, i.e., the solid electrolyte (E) and the product (D). Since mass and charge transport occur in solid state ionic materials, the conductivity mechanism imposes some restrictions, and fundamental considerations in a PEVD system can be obtained through the local equilibrium approach. In the following, mass and charge transport in both phases will be discussed. 

The ability of PEVD to deposit thin solid state ionic materials can be expressed by the ratio of the Y to X direction growth length, y/x, which can be written as... 

During the last 20 years, we have witnessed the active development of solid state ionics associated with the study of ionic and electronic processes in solid state ionic materials. The investigation of energy converting applications to use ionic transport in solid state ionic materials is booming. The present availability of numerous types of solid state ionic materials allows for electrochemical reactions to be carried... 

Delmas, C. Saadune, I. Auradou, H. Menetrier, M. Hagenmuller, P. Solid State Ionics Materials and Applications Chowdari, B.V., et al., Eds. World Scientific Singapore, 1992 255. 

The present account of the computational techniques will be brief since comprehensive reviews are given elsewhere.In general, three classes of techniques have been employed in the study of solid state ionic materials atomistic (static lattice), molecular dynamics (MD) and ab initio quantum mechanical methods. 

Chowdari BVR, Chandra S, Singh S, Srivastava PC (eds) (1992) Solid state ionics, materials and applications, World Scientific, Singapore... 

Chandra, S. and Chandra, A. Rroceedings of National Academy of Sciences, India, SectionA, RartlE Solid state ionics materials aspect, pp. 141-181 (1994). 

A. D Epifanio, B. Mecheri, F.C. Weise, S. Greenbaum, E. Traversa, S. Licoccia, SPEEK-based composite membranes for direct methanol fuel cells, in E. Traversa, T.R. Armstrong, K. Eguchi, M.R. Palacin (Eds.), Solid-State Ionics, Materials Research Society, Warrendale, PA, USA, 2009, pp. 93-98. 

Some selectivity of Si3N4 to other ions (e.g., Li, K, AF ) can be promoted by the method of ion implantation of these ions [76, 77]. A variety of inorganic layers, mainly for H, Na, and K sensing, including transition-metal oxides, has been investigated [78-81]. Other solid-state ionic materials such as jS and jS" alumina or NASICON (Na3Zr2Si2POi2) have also been explored as ion-selective materials. 

Defect Chemistry in Solid State Ionic Materials... 

Defect Chemistry in Solid State Ionic Materials, Fig. 1 Defect structure of Mi 60 versus oxygen activity at fixed temperature, as calculated assuming Ki >> Ks (not to scale). The triangles represent the oxygen exponents m of the piecewise solutions... 

Defect Chemistry in Solid State Ionic Materials, Fig. 3 Defect structure of E2O3 doped, stoichiometric MO with the Frenkel disorder as the majority, not to scale. Small triangles denote the slopes. Note the intrinsic regime at the high temperatures and extrinsic regime at the low temperatures... 

Conductivity of Electrolytes Defect Chemistry in Solid State Ionic Materials Defects in Solids Dynamic Methods in Solid-State Electrochemistry Electrolytes, Classification... 

Weppner W (2000) Concepts and materials aspects of developing solid state ionic devices. In Chowdari BVR, Wang W (eds) Proceedings of the 7th Asian conference on solid state ionics materials and devices. Word Scientific, River Edge, NJ, pp 3-12... 

Owing to participation of Latvian and Swedish scientists in the field of chemically sensitive FET and MOS structures it was possible to utilize the technological facilities of the Microelectronics enterprise in Latvia in making an integrated smart sensor as a matrix of chemically sensitive FETs by using silicon based microtechnology Thereby the first steps of pTAS in Latvia are made in the direction of integration of solid state ionic materials with FET and MOS structures to develop new chemically sensitive structures and systems... 

As materials for sensing elements different catalytic metals, metal oxides and their composites are used in the form of thin and/or thick films obtained by different deposition, evaporation or sol-gel technologies. The electronic and ionic properties of the surfaces (interfaces) and bulk of such materials are sensitive to different gas molecules in the environment. The gas sensitivity is based on physical and chemical phenomena on the catalytic metals and solid state ionic materials. 

Chowdary, B.V.R., Chandra, S., and Shri Singh, Eds., Solid State Ionics. Materials and Applications, World Scientific, Singapore, 1992. 

II. Applications of Solid State Ionic Materials to Batteries... 

---