Criticaldislocation

A function to predict the disordering behavior of crystalline materials on milling using the critical dislocation density model.

Criticaldislocation

Author - Mustafa Bookwala (Wildfong Lab, Duquesne University)

This function estimates the critical dislocation density (Dd) using the critical dislocation model and compares it with the prohibitive dislocation density (PDd) and gives a prediction based on the model. This code is developed to work for all materials. First all the inputs are asked in the units which are readily available and then converts in to units that are required for the calculation. Then it runs a for loop to estimate at which dislocation density does the dislocation free energy (dGd) and free energy of amorphous form (dGam) become equal and if that density is reached then the loop breaks. Also, within the for loop if the value for Y becomes negative (meaning a solution cannot be reached), the for loop breaks so as to save computation time. This is followed by PDd calculation. Finally after calculations are complete, a new matrix of different Dd is made and dGd is calculated at each Dd so that a for loop can be used to plot the relationship between dGd Vs. Dd. The PDd and Dd are ultimately compared and a decision is made.

References

1) Wildfong PLD, Hancock BC, Moore MD, Morris KR. Towards an understanding of the structurally based potential for mechanically activated disordering of small molecule organic crystals. Journal of pharmaceutical sciences. 2006 Dec 1;95(12):2645-56.

2) Lin Y, Cogdill RP, Wildfong PLD. Informatic calibration of a materials properties database for predictive assessment of mechanically activated disordering potential for small molecule organic solids. Journal of pharmaceutical sciences. 2009 Aug 1;98(8):2696-708.

3) Tromans D, Meech JA. Enhanced dissolution of minerals: stored energy, amorphism and mechanical activation. Minerals engineering. 2001 Nov 1;14(11):1359-77.