
1^{st} order transition 
Continuous transition 
1^{st} derivatives of G 
Discontinuous at transition point 
Continuous 
Order parameter 
Discontinuous across coexistent curve (except at the critical point) 
Continuous 
Symmetry 
May or may not be broken 
Aways broken 
The GinzburgLandau theory is a mean field
theory that describes an orderdisorder transition. Thus, the low temperature, or ordered, phase
is characterized by a nonzero order parameter η, which vanishes in the high temperature, or disordered phase. In a continuous transition, there is also an
accompanying change of symmetries with the ordered phase having the lower
symmetries. The molar free energy φ is assumed to be analytic (i.e., a
where terms
3.G.1. Continuous Phase Transitions
3.G.2. First Order Transitions