文档介绍：S. Singh / Physics Reports 324 (2000) 107}269 107
PHASE TRANSITIONS IN LIQUID CRYSTALS
Shri SINGH
Department of Physics, Banaras Hindu University, Varanasi - 221 005, India
AMSTERDAM } LAUSANNE } NEW YORK } OXFORD } SHANNON } TOKYO
Physics Reports 324 (2000) 107}269
Phase transitions in liquid crystals
Shri Singh
Department of Physics, Banaras Hindu University, Varanasi-221 005, India
Received March 1999; editor: . Mills
Contents
1. Introduction 110 6. Re-entrant phase transitions (RPT) in liquid
. Liquid crystals: an overview 110 crystals 204
. Classi"cation of liquid crystals: symmetry . Examples of single re-entrance 205
and structures 114 . Examples of multiple re-entrance 208
2. Order parameters 120 . Theories for the RPT 209
. De"nition of microscopic order parameters 122 7. Uniaxial nematic}biaxial nematic (NN")
. De"nition of a macroscopic order phase transition 215
parameters 125 8. Phase transitions involving smectic phases 221
. Relationship between macroscopic and . Smectic A}smectic C transition 221
microscopic order parameters 126 . Nematic}smectic A}smectic C (NS S!)
3. Phase transitions in liquid crystals 126 multicritical point 223
. Thermodynamics of phase transitions 129 . Transitions involving hexatic smectic
. Order of phase transition 130 phases 225
. Experimental determination of some 9. Computer simulations of phase transitions in
phase transition properties: a critical liquid crystals 226
comment 131 . Lebwohl}Lasher model 227
4. Nematic}isotropic phase transition 133 . Hard-core models 228
. Landau}de Gennes theory of the uniaxial . Gay}Berne model 232
nematic}isotropic (NI) phase transition 135 10. Phase transitions in liquid crystal polymers
. The hard particle or Onsager-type theories 151 (LCPs) 234
. The Maier}Saupe (MS) type theories 158 . Nematic order in polymer solutions 235
. The van der Waals (vdW) ty