Landau-Lifshitz theory, phase transitions

Landau-Ginzbuig coefficients 282 Landau-Ginzburg Hamiltonian, critical 303 Landau-Khalatnikov mechanism 564 Landau-Lifshitz theory, phase transitions 366 Landau-Peierls instabilities 285, 647 Langmuir-Blodgett film, atomistic simulations 85 Laplace equation 445... 

The fundamental problem of the theory of ferroelectricity is the origin of stmc-tural phase transition, when the spontaneous polarization appears or disappears. At first, we will describe such phase transition from the thermodynamic point of view. Phenomenological ferroelectricity theory is based on the works of Landau and Lifshitz (1974) and Devonshire (1949,1951). Starting point of the theory is the elastic Gibbs potential G, where we would select polarization P (except of electric displacement D) as an independent variable. Therefore the Gibbs potential is... 

A new look at the thermodynamics of structural phase transitions has been provided by the Landau theory (Landau and Lifshitz, 1980 Toledano and Toledano, 1987). Its principal element is a Gibbs free energy expansion in the form of a Taylor series in an order parameter Q. As the value of Q cannot be directly assessed, the coefficients of the power series... 

Holyst and Schick [339] study the phase diagram and scattering of AB symmetric diblock copolymers diluted with A and B homopolymers (in equal concentrations) having the same chain length NA = NB = N as the copolymers. Constructing a Landau expansion, they show that the wave vector q vanishes at a critical copolymer concentration ordering transition there as that of a Lifshitz tricritical point, where the disordered phase, lamellar phase, A-rich and B-rich separated phases can coexist. The critical behavior near this point is expected to deviate strongly from mean field theory [339]. 

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