Dr. Prasad, you may consult the following references. These are related to heterogeneous non-reciprocal nucleation.

1.Southin and Chadwick Acta Met 26(1978)223, 2.Biswell and Chadwick Acta Met. 28(1980)209. 3. Cantor and Doherthy Acta Met. 17(1979) 33

Thanks a lot Professor Ojha.

This paper may be useful: B. A. Mueller, J. H. Perepezko. Undercooling of aluminum, Metallurgical And Materials Transactions A. 1987 ,18A, 1143-1150.

Dear Dr. Prasada,

you should also consult the following paper by Royset, which investigated freezing out the diffusion and thus the nucleation in AA6xxx alloys by cooling down to -40°C. 

There, no age-hardening is happening and thus no diffusion of added elements. 

You could also consult our publications showing the same effect but with different methods

With best regards

Torsten Staab

@ARTICLE{royset:06, AUTHOR = {J. Royset and T. Stene and J.A. Saeter and O. Reiso}, TITLE = {The Effect of Intermediate Storage Temperature and Time on the Age Hardening Response of Al-Mg-Si Alloys}, JOURNAL = {Mater.~Sci.~Forum}, YEAR = {2006}, VOLUME = {519-521}, NUMBER = {}, PAGES = {239}, KEYWORDS = {Confernce proceedings: Aluminium Alloys 2006 - ICAA10} }

@ARTICLE{klobes:08a, AUTHOR = {B. Klobes and T.E.M. Staab and E. Dudzik}, TITLE = {Early stages of decomposition in {Al} alloys investigated by {X-ray} absorption}, JOURNAL = {phys.~stat.~sol.~(RRL)}, YEAR = {2008}, VOLUME = {2}, NUMBER = {4}, PAGES = {182-184}, KEYWORDS = { } }

@ARTICLE{klobes:08b, AUTHOR = {B. Klobes and T.E.M. Staab and M. Haaks and K. Maier and I. Wieler}, TITLE = {The role of quenched-in vacancies for the decomposition of aluminium alloys}, JOURNAL = {phys.~stat.~sol.~(RRL)}, YEAR = {2008}, VOLUME = {2}, NUMBER = {5}, PAGES = {224--226}, KEYWORDS = { } }