Structural and magnetic phase transitions in minerals / Структурные и магнитные фазовые переходы в минералах

Phase transitions in minerals are of interest to a wide spectrum of scientists - geologists, mineralogists, solid state chemists, and physicists. We have now reached the point where mean field theory or Landau Theory of phase transitions as a function of temperature, pressure, or chemical composition can be usefully applied to natural materials, resulting in an improved understanding of the thermodynamics of significant constituents of the earth. Given the chemical complexity of so many silicate solid solutions, there are two distinct approaches to the problems posed by common minerals: one is to concentrate on model compounds which could be synthetic analogs or natural endmembers; the other is to work on typical minerals, with all the disorder and inhomogeneity that this implies. Model compounds provide the elements needed to build up a realistic understanding of the thermodynamic behavior of natural inorganic materials in all their complexity. In the first part of the book, a number of papers are devoted to structural phase transitions in quartz, Na- and Ca- feldspars, MgSi03 perovskite, and PbI2, where Landau Theory and lattice and molecular dynamics have been used to explain or predict thermodynamic behavior. A different thermodynamic approach has been used to understand phase separation and atomic ordering in solid solutions such as olivines, pyroxenes, rhombohedral carbonates and oxides. <...>