DISCUSSIONS OF THE FARADAY SOCIETY No. 23, 1957 MOLECULAR MECHANISM OF RATE PROCESSES IN SOLIDS THE FARADAY SOCIETY A g e n t s for the Society’s Publications : The Aberdeen University Press Ltd. 6 Upper Kirkgate AberdeenThe Faraciay Society I-esei-ves the copyright OJ all Coinmunications published iri the L' Discrtssions '' PUBLISHED . . . 1957 PRINTED IN GREAT BRITAIN AT THE UNIVERSITY PRESS A B E K D E E NA GENERAL DISCUSSION ON MOLECULAR MECHANISM QF RATE PROCESSES IN SOLIDS A GENERAL DISCUSSION on the Molecular Mechanism of Rate Processes in Solids was held at the invitation of, and in conjunction with the Koninklijke Nederlandse Chemische Vereniging at the Koninklijke Institut voor de Tropen, Amsterdam, during April 15th-l8th, 1957. Members and visitors, who included scientists from America, Australia, Belgium, France, Germany, Italy, Netherlands, Sweden, Switzerland and the United Kingdom were welcomed at an official re- ception given by the Burgomaster of Amsterdam at the Rijksmuseum and at Koninklijke Institut by the President of the Faraday Society, Mr. R.P. Bell, F.R.S., and the President of the Koninklijke Nederlandse Chemische Vereniging, Mr. Gerding, who shared the duties of Chairman during the Discussion. 3A GENERAL DISCUSSION ON MOLECULAR MECHANISM QF RATE PROCESSES IN SOLIDS A GENERAL DISCUSSION on the Molecular Mechanism of Rate Processes in Solids was held at the invitation of, and in conjunction with the Koninklijke Nederlandse Chemische Vereniging at the Koninklijke Institut voor de Tropen, Amsterdam, during April 15th-l8th, 1957.Members and visitors, who included scientists from America, Australia, Belgium, France, Germany, Italy, Netherlands, Sweden, Switzerland and the United Kingdom were welcomed at an official re- ception given by the Burgomaster of Amsterdam at the Rijksmuseum and at Koninklijke Institut by the President of the Faraday Society, Mr. R. P. Bell, F.R.S., and the President of the Koninklijke Nederlandse Chemische Vereniging, Mr. Gerding, who shared the duties of Chairman during the Discussion. 3CONTENTS PAGE INTRODUCTION. By C. J. F. Bottcher . . 7 A. RELAXATION PROCESSES- A Mechanical and Thermodynamical Theory of Non-Linear Re- By H. C. Brinkman and F. Schwarzl laxation Behaviour of Solids. 1 1 The Mechanism of Low Temperature Mechanical Relaxation in Deformed Crystals.By A. Seeger, H. Donth and F. Pfaff . . 19 Dielectric Relaxation in Solid Hydrogen Halides. By R. H. Cole and S. Havriliak, Jr. . . 31 Dielectric Relaxation Processes in Lithium, Sodium and Potassium Halides. By J. S. Dryden and R. J. Meakins . . 39 Dielectric Relaxation and the Electrical Conductivity of Ice Crystals. By H. Granicher, C. Jaccard, P. Scherrer and A. Steinemann . 50 Dielectric Loss in Insulating Solids caused by Impurities and Colour Centres. By J. Volger . . 63 GENERAL DrscussIoN.--Dr. Y. Haven, Dr. H. C. Brinkman and MI-. F. Schwarzl, Dr. J. Wood and Dr. A. Suddaby, Prof. A. R. Ubbelohcie, Prof. F. C. Frank, Prof. J. S. Koehler, Dr. A. Seegzr, Dr. J. Volger, Dr. J. S. Dryden, Prof. J. H. de Boer, Dr.H. Granicher, Prof. F. G. Fumi, Dr. A. B. Lidiard, Dr. R. A. Sack, Dr. A. Steinemann, Prof. R. M. Barrer, Dr. M. Eigen, Dr. J. L. Meijering, Dr. J. Meinnel . . 72 B. STEADY-STATE PROCESSES NOT INVOLVrNG LATTICE --ARRANGEMENT- Introduction. By J. S. Koehler and F. Seitz . . 85 Lattice Calculations on Point Imperfections in the Alkali Halides. By F. G. Funii and M. P. Tosi . . 92 Diffusion Coefficients in Solids, Their Measurement and Significance. By J. Crank . . 99 Some Fundamental Aspects of the Mechanism of Diffusion in Crystals. By I<. Conipaan and Y . Haven . . 105 Thermoelectric Power of Ionic Crystals. By R. E. Howard and A. B. Lidiard . . 113 Dislocations and Point Defects. By F. C . Frank . . 122 56 CONTENTS Abnormal Values of A and E in Migration Processes.By A. R. Ubbelohde . . 12s Diffusion of Nickel-63 in Nickel Oxide (NiO). By R. Lindiier and A. akerstrom . . 133 Diffusion in Tonic Crystals and the Process of Sintering. By W. Jost and H. J. Oel . . 137 Point Defects Produced by Irradiation and their Annealing in Tonic and Covalent Crystals. By F. P. Clarke . . 141 GENERAL DIscuSSIoN.--Prof. F. G. Fumi, Prof. R. M. Barrer, Prof. R. A. W. Haul, Dr. J. Crank, Dr. L. E. J. Roberts, Dr. Y. Haven, Dr. A. Seeger, Prof. J. S. Koehler, Dr. P. Ruetschi, Prof, W. Jost, Dr. A. B. Lidiard, Prof. A. R. Ubbelohde, Prof. J. H. de Boer, Prof. F. C. Frank, Dr. G. Saloman, Mr. J. F. Laurent, Dr. D. A. Young, Dr. A. G. Maddock, Mr. F. P. Clarke, Mr. G. N. Walton 155 C. STEADY-STATE PROCESSES INVOLVING LATTICE RE-ARRANGEMENT- Tntroduction. By J. H. de Boer . . 171 Mechanism and Kinetics of the Allotropic Transformation of Tin. By W. G. Burgers and L. J. Groen . , 183 Orientational Effects in the Polymorphic Transformations of Sulphur. By C. Briske and N. K. Hartshorne . . 196 Azide Decompositions. By F. C. Tompkins and D. A. Young . . 202 The Chemical Effects of Radiative Thermal Neutron Capture. Part .?.-The Kinetics of a Radical Recombination Process of Solids. By M. M. de Maine, A. G. Maddock and K. Taiigbd . . 211 GENERAL DIscussIoN.-~r. P. W. M. Jacobs, Dr. K. H. Lieser, Dr. J. Meinnel, Dr. R. P. Rastogi, Dr. L. J. Groen, Dr. W. J. Dunning, Dr. N. E-I. Hartshorne, Dr. G. Salomon, Prof. J. H. de Boer, Dr. F. C. Tompkins and Dr. D. A. Young, Dr. J. Y . Macdonald, Dr. T. C . Waddington and Dr. Peter Gray, Dr. A. B. Lidiard, Dr. F. S . Stone 220