i already have data concerning solid fraction at various temperatures. Suggestions in the form of papers or books will also be helpful. I am using SPH to solve the problem.
Which material are you actually working with? A very convenient way of modelling release of latent heat is to adjust the cp value in the solidification interval. You Can derive this adjusted value from your data on solid fraction as a function of temperature.
You can actually avoid iterating for the non- linearity introduced by the adjusted cp value if you use the so called push back algorithm.
Modelling solidification this way is simple, numerically efficient and robust, however it cannot account for e.g. undercooling. In this case you need to apply a real source term in the heat conduction equation.
The above mentioned method is described in detail in: Fundamentals of Numerical modelling of Casting processes, edited by Jesper Hattel