Analytic scaling functions for percolative metal-insulator phase transitions fitted to AlxGe1-x data

The definition of the percolation scaling functions and an equation for the conductivity of a binary composite are combined to obtain two percolation scaling functions F+(x(+)) and F-(x(-)). F+(x(+)) is the function valid above the percolation threshold (phi(c)) and F-(x(-)) below. Using numerical simulation, it is then shown that these two functions display the principle properties required for them to be scaling functions. Previously reported experimental data on AlxGe1-x, where phi(c) was determined from superconductivity measurements, is replotted in the scaling form and shown to agree with the "best fit" F+(x(+)) and F-(x(-)). (C) 1998 Elsevier Science B.V. All rights reserved.