This distance could not be obtained from
HRTEM images because the high vacuum could decrease the
distance. Thus the distance from the HRTEM image was taken
as the first approximation and then the PXRD pattern was
calculated with the aid of the Debye formula and compared
with the experimental one. This was repeated for several
values of the parameter until a reasonable match was
achieved. The distance between walls was changed in the
model in order to obtain a good match of the first diffraction
peak position. This peak corresponds to the direction of
stacking walls as can be seen in Fig. 2.