 Consequently, a relation of formula_15 in terms of the diffusion coefficient is obtainedformula_23.Further considerations can be made in order to study temperature dependence.Therefore, Einstein-Stokes relation is introduced under the consideration of a spherical shapeformula_24, where formula_25 is the material's viscosity.Considering the last two expressions, it is seen that formula_15 formula_27.If formula_28, being formula_29 the melting temperature, the ensemble gains high velocity and makes formula_15 and formula_5 to increase and hence, formula_1 decreases.