Wzór Scherrera : stulecie błędnych praktyk

We present the sources of uncertainty in the evaluation of grain size in nanomaterial. The calculations are made for the same diffraction pattern using Scherrer and Williamson-Hall methods. As an example we use the CoCr₂O₄ nanocrystal. The comparison of results from different calculations, methods and programs is made just to show how important is the (correct) choice of a method and its internal parameters. The data from well known Scherrer formula, show that the difference in obtained results exceeds 100% up to even about 350%. This indicates that in any case the Scherrer formula could not give the correct and reliable value for crystallite size. As a consequence, the wide use of this formula is a great error providing the incorrect results.