J. MATER. CHEM., 1991,1(3),487-488 BOOK REVIEWS Cambridge Topics in Mineral Physics and Chemistry Vol. 1. Phase Transitions in Ferroelastic and Co-elastic Crystals. Ed. E. K. H. Salje. Cambridge University Press, Cambridge, 1990. Pp. xvi +366+ xlviii +iii. Price €50.00 (Hardback) One of the great problems in the mineralogical sciences is the complexity of the phase-transition behaviour shown by very common natural materials such as the feldspars. Our under- standing of such transitions has been revolutionised over the last few years by the application of Landau theory to these systems. It has become apparent that the different ordering and distortional processes involved in the transitions, their interactions, and even the pressure and temperature variation of properties such as heat capacity and birefringence away from the transition point, can be readily rationalised and accurately modelled. The concepts involved are more familiar in solid-state chemistry and physics than in classical mineralogy.This timely book is therefore divided into two parts. The first 12 chapters (Salje) constitute an extended review of the necessary theory. The second half is a collection of case studies by various authors, illustrating the application of the theory to different problems. The title of the book is perhaps unfortunate, making it appear rather more specialized than it actually is. However, many observed phase transitions, probably the majority of them, can be described in terms of symmetry change from group to subgroup or vice versa.As Hatch and Stokes state (ch. 19), ca. 8 1YOof all possible space group-subgroup tran-sitions can exhibit some form of associated elastic behaviour, bringing them within the scope of this book. The solid-state science is undeniably good. The systems discussed range from the petrologically important (plagioclase, leucite) to the technologically important (high- T, supercon-ductors) to simple molecular materials (SFs, CHBr,). The two main aspects of the book which invite comment are the presentation and the intended audience. The first 12, didactic chapters are bracketed by helpful introduction and summary paragraphs. However, they are marred by careless proof-reading. For instance, Equation 10.19, featuring a 24th degree polynomial, is derived from ‘Equations 10.4.5 and 10.4.6‘ which do not exist as such! They are certainly not to be found further on, in Section 10.4.They are in fact Equations 10.12 and 10.13, in Section 10.3. Indexing and referencing problems abound. Chapter 13 (Giittler) discusses the application of infrared spectroscopy to the transitions in the important minerals cordierite and albite. No mention of cordierite is to be found in the index, and albite does not appear in this context. Appendix Table2 is an extensive compilation of phases showing ferro- and co- elastic transitions, with references. Although useful, it is clearly not comprehensive since it does not include HCN, reviewed by Dove (ch. 18).It is asserted in the preface that Part 1 ‘essentially forms a textbook on the subject and can thus be used for teaching or learning at mainly an undergraduate level’. Unfortunately, it cannot be said that this aim is entirely satisfied by the present edition. There is a general tendency to pull equations out of thin air (or to give references to journals) in Part 1, with minimal in situ explanation of fundamentals. This is further compounded by the proof-reading errors noted above, the whole generally militating against use as a textbook by second-year undergraduates. There is also the problem of which undergraduate course could best assimilate this subject matter. Physics or chemistry students are likely to be confused by the structurally complex mineralogical systems on which the book concentrates.Earth scientists will wonder at the assumed prior knowledge of group theory and elastic theory. No attempt has been made to discuss geological ramifications of the mineral behaviour that is described. Above all, one is forced to question whether the time required to master phase transitions at this level is wisely spent during a 3-year degree course, at the expense of a broader overview of a discipline. All that said (mainly, it must be confessed, owing to an unguarded claim in the preface), the fact remains that this is a most welcome addition to the tertiary solid-state literature. The book deals expertly with complex issues that are all too commonly avoided, and which deserve wider exposure.This book will undoubtedly provide the basis for stimulating interdisciplinary postgraduate courses, and should also be a welcome addition to any Physics, Chemistry, Earth Science or Materials Science library. In the long term its influence is likely to be considerable. D. M. Adams A. G. Christy Received 27th March, 1991 Introduction to Polymer Dynamics. by P. G. de Gennes. Cambridge University Press, Cambridge, 1990. Pp. vi +58. Price p/b S6.95, h/b €20.00. This is a gem of a book and is recommended reading for all who are interested in a fundamental understanding of polymer behaviour. The book is based on a course of lectures given at the Polytechnic of Milan in 1986 and focuses attention on basic concepts in the behaviour of polymers without involving the more advanced mathematical formalism found in the larger, established texts.It is short, containing only some 58 pages, including the index, and the choice of material is clearly highly selective, reflecting some of Professor de Gennes’ own special interests. Nevertheless, the author is able to illustrate the rich variety of behaviour in these practically important materials and to show that many of the properties can be at least qualitatively understood with fairly simple ideas. Potential readers should, however, not take the title too literally: it is not so much an introduction as a short and highly stimulating overview. A newcomer to the field will find it useful to keep one of the more established texts (such as the same author’s Scaling Concepts in Polymer Physics) close to hand for frequent reference. What makes the book so stimulating (and successful) is not rigorous theoretical treat- ment but the stamp of Professor de Gennes’ own unique style, seeking wherever possible to explain complex phenomena in the most straightforward and transparent way.Each chapter ends on an up-beat, emphasising the oppor- tunities for new research that remain in polymer dynamics. References are provided at the end of the book. Chapter 1 is concerned with general concepts as applied to the motions of polymer chains in solvents and in melts such as diffusion and internal deformation modes, and there are also brief mentions of viscoelasticity, reptatation and chemical kinetics in entangled media.The treatment is brief but critical. Chapter 2 is concerned with the application of simple statistical ideas to examine the possible conformations of proteins around an active site. In a protein the hydrophilic amino acids can act as specific receptors at an active site, but of course they are linked together by relatively long loops of the peptidic chain. There is considerable interest in estimating the minimum size required for these loops for a given active site. Chapter 3 is not specifically concerned with polymers but does feature a discussion of the dynamics of dry spreading of liquids on solids. Polymers and 4He are picked out as special cases of fluids where there are still important questions concerning spreading properties! It is well known that flexible polymers in dilute solution can reduce turbulent losses in a flowing fluid.This is quite a complex phenomenon, however, involving the coupling between hydrodynamic aspects of turbulence and the visco- elastic behaviour of polymer chains. In Chapter 4, which is the longest, the author shows that many features of the problem can be understood by emphasising the elastic and not the viscous response of a polymer chain. Again the approach is fairly qualitative, but presents useful insights for the guidance of future experiments. J. H. R. Clarke Received 1lth April, 1991 Springer Proceedings in Physics. Ed. H. K. V. Lotsch. Vol 51:The Physics and Chemistry of Organic Superconductors.Proceedings of the ISSP International Symposium, Tokyo, Japan, August 28-30,1989. Ed. G. Saito and S. Kagoshima. Spri nger-Verlag, Berlin-Heidel berg-New York-London-Paris-Tokyo-Hong Kong, 1990. Pp. xxii +476. Price DM 114.00. ~~ ~~ The field of superconductivity waxes and wanes. The organic molecular variety, comprising modest-sized components (ET adducts and the like) have not exceeded the elemental or elemental-alloy systems in the critical transition temperature T,, but they have provided a vast increase in scope for the study of superconductivity. Complexes with the DMIT ligand form a companion group. These acronyms are not helpful to the neophyte but then this is not an introduction to the subject, it is the proceedings of an international symposium.The conference title had clearly been chosen before Bednorz and Muller upstaged the particular area named, with T, in the low teens, by introducing the ceramic oxocuprate class with Tc>125K, and the introductory contributions to the proceedings cope with this by comparative reviews of the organic and inorganic systems. To quote, ‘the nature of the pairing interaction remains an open question in organic superconductors .... However, a non-phonon-mediated pairing mechanism [is] quite plausible.’ The several reviews are excellent in providing the contexts for the papers that follow. The papers, reprinted from camera- J. MATER. CHEM., 1991, VOL. 1 ready copy, are a mixture of research with extensive review material of the contributors’ own work.Theoretical and experimental work leads to predictions of desiderata which can only be deemed ‘hopeful’. This rnklange is again not for the neophyte. Many papers cover systems which should, or might, be superconductive; some comprise organic prep- arations only. However, a final summary by Ishiguro makes a useful framework and I, for one, benefited by reading this early rather than last, even if it does provide more of an index than a conflation of views. The conference sections were: I, Organic Superconductors- Overview and Comparison with Oxide Superconductors (three papers); 11, Metal Coordinated Organic Conductors and Related Materials (nine papers); 111, TMTSF Family- Superconductivity and Spin-Density Waves (11 papers); IV, BEDT-TTF Family-Superconductivity (1 6 papers); V, BEDT-TTF Family -Fermiology and Related Subjects (10 papers); VI, DMET Salts and their Families (five papers); VII, Crystal and Electronic Structures (18 papers); VIII, Structural Design of Organic Superconductors (four papers); IX, New Molecules and Materials (17 papers); X, Theory (nine papers).The authorship is suitably international, some two-thirds being of host-country origin. It was intriguing to see work on, for example, Langmuir-Blodgett films included. Many of the systems reported were ‘might have beens’, a fair fraction are metallic rather than superconducting, and some not even that. What is to be said by way of special commendation? This is another milestone (of many) on the route to ever increasing understanding of the solid state, particularly superconduc- tivity; to cite particular names would be invidious, but the expected workers from both East and West have contributed.In a generalisation on the field, one must say that not a great deal of the development of superconductivity studies on the organic systems was responsible for leading directly to the discovery of the inorganic oxocuprate superconductors; how- ever, with hindsight, parallels can be drawn in the behaviour of the two classes. Following Day’s review, these are the importance of low dimensionality and the proximity of mag- netic and superconducting states tunable by pressure or chemical composition, consequences of both classes being narrow-band systems. For those interested and practising in the field, this is an interesting read in parts; clearly, to learn about the oxocuprate systems, one must read elsewhere. Three groups of superconductive materials have now been established: elemental metals and their alloys, organic adducts and most recently the oxides. What next? All I can say is: watch this space (or the adjoining). D. R. Rosseinsky Received 1lth April, 1991