  A model for nucleation of second phase at or around dislocation in a
crystalline solid is considered. The model employs the Ginzburg-Landau theory
of phase transition comprising the sextic term in order parameter in the Landau
free energy. The ground state solution of the linearized time-independent
Ginzburg-Landau equation has been derived, through which the spatial variation
of the order parameter has been delineated. Moreover, a generic phase diagram
indicating a tricritical behavior near and away from the dislocation is
depicted. The relation between the classical nucleation theory and the
Ginzburg-Landau approach has been discussed, for which the critical formation
energy of nucleus is related to the maximal of the Landau potential energy. A
numerical example illustrating the application of the model to the case of
nucleation of hydrides in zirconium alloys is provided.
