Formation of Defects at High Temperature Plastic Deformationof Gallium ArsenideDISSERTATIONZur Erlangung des akademischen Gradesdoctor rerum naturalium (Dr. rer. nat.)vorgelegt derMathematisch-Naturwissenschaftlich-Technischen Fakultät(Mathematisch-naturwissenschaftlicher Bereich)der Martin-Luther-Universität Halle-WittenbergvonDipl. Phys. Vladimir V. Mikhnovichgeb. am 03. Oktober 1978 in Voskresensk, RusslandGutachterin/Gutachter1. PD Dr. Hartmut S. Leipner2. Prof. Dr. Nikolai Bagraev3. Prof. Dr. Jörg WeberHalle (Saale), den 14 März 2006urn:nbn:de:gbv:3-000010038[http://nbn-resolving.de/urn/resolver.pl?urn=nbn%3Ade%3Agbv%3A3-000010038]CONTENTS21. Introduction……………………………………………………………...42. Plastic Deformation…………………………………………………….1.1 Deformation curve during stretching ………………………………………….. 41.2 Movement of dislocations ……………………………………………………… 51.3 Multiplication of dislocations …………………………………………………. 91.4 Kinetics of movement of dislocations …………………………………………. 111.5Formation of point defects……………………………………………………… 162.5.1 Models………………………………………………………………….. 162.5.2. Kinetics of formation of point defects…………………………………. 171.6Dislocations in the diamond structure…………………………………………. 22253. Positron Annihilation Spectroscopy……………………………………..3.1Positronium in vacuum…………………………………………………………. 253.2Positronium in crystals………………………………………………………….. 263.3Annihilation of Fre Positrons …………………………………………………. 283.4Positron annihilation on defects…………………………………………………. 303.4.1.