A statistical theory of nucleation in the presence of uncharacterised impurities
Sear, RP (2004) A statistical theory of nucleation in the presence of uncharacterised impurities Physical Review E v70, 021605 (2004) .
First order phase transitions proceed via nucleation. The rate of nucleation varies exponentially with the free-energy barrier to nucleation, and so is highly sensitive to variations in this barrier. In practice, very few systems are absolutely pure, there are typically some impurities present which are rather poorly characterized. These interact with the nucleus, causing the barrier to vary, and so must be taken into account. Here the impurity-nucleus interactions are modelled by random variables. The rate then has the same form as the partition function of Derrida's random energy model, and as in this model there is a regime in which the behavior is non-self-averaging. Non-self-averaging nucleation is nucleation with a rate that varies significantly from one realization of the random variables to another. In experiment this corresponds to variation in the nucleation rate from one sample to another. General analytic expressions are obtained for the crossover from a self-averaging to a non-self-averaging rate of nucleation.
|Divisions:||Faculty of Engineering and Physical Sciences > Physics|
|Deposited By:||Mr Adam Field|
|Deposited On:||27 May 2010 15:06|
|Last Modified:||20 Sep 2012 13:19|
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