O Madelung – författare

Vols. III/17a-i and III/22a, b (supplement) on semiconductor physics and technology have been published earlier, the latter covering new data on the technologically important group IV elements and III-V, II-VI and I-VII compounds only. The wealth of further data from the last decade is now being critically evaluated by over 30 well-known experts in the field of semiconductors. To meet the demands of today's scientists and to offer a complete overview on semiconductor data all data available so far are published in the following way: a series of seven subvolumes covers only the supplementary data to volumes III/17 and 22. Enclosed to each subvolume, a CD-ROM contains a complete, revised and update edition of all relevant data. For each individual substance the information is presented in userfriendly documents, containing data, figs. and references. Easy access to the documents is provided via substance and property keywords, listings and full text retrieval.

Sect. 1. 247 We have already stated that the subject of ionic conductivity can be properly regarded as one part of the wider study of imperfections, and it is on account of the coherence and unity of this wider subject that ionic conductors acquire their interest [4J. Thus the ideas of mobile interstitial atoms and vacant lattice sites are relevant to a wide range of phenomena; for example diffusion in solidsl, chemical reactions between two solids and between asolid and agas (e. g. tarnish- 3 ing reactions) 2, and annealing of radiation damage . There are, of course, imper- fections such as dislocations whose properties cannot be studied to any great extent through ionic conductivity measurements. However the existence of charges on the ions and the absence of electronic conduction enables the pro- perties and concentration of the simple localised lattice defects to be studied with greater certainty and more directness than is possible in, say, metals. This is true of the original development of the theory of lattice defects by FRENKEL [2J, SCHOTTKY [3J, [5J and WAGNER [5J, and is also true at the present time. Two examples may be mentioned.Firstly the diffusion of impurity atoms in met als may sometimes involve the formation of relatively stable pairs formed from an impurity atom and a vacan- cy [6]. In NaCl (an ionic conductor), such pairs are readily formed between a 2 Na+ vacancy and a substitutionally dissolved multivalent impurity ion, e. g.