CBED (convergent beam electron diffraction) is known as one of the most sensitive techniques for local lattice parameter determination using electrons. I have no doubts regarding the precision of this technique, but as far as I understand CBED the most important input is the electron energ since from this the electron wavelength and, thus, the lattice parameter will be derived. In other words, to me it seems that the accuracy is more restricted by the believe of the high voltage shown by the TEM, not even mention the local sample heating. If this is right: How accurate is CBED? If somebody is writing 4.466873261 Å...down to which decimal place this number is credible?
It is not so convinced to use that number. The accuracy of CBED is not that excellent. The variation in lattice parameters of +/-0.005 A could be resolved by CBED (see the paper: http://www.minersoc.org/pages/Archive-MM/Volume_51/51-359-33.pdf)
The sensitivity of lattice parameter measurement using CBED is on the order of 10^(−4). The method is also used for strain mapping.
@ A. Lotnyk: thinking about your answer, I have the impression that this matches to a RELATIVE change (precision) and not to the absolute lattice parameter determination (accuracy) I was asking for. Your comment also matches to the statement given by D. T. Ngo, right? delta a/a ? On the other hand: how suitable is a strain mapping applied on a material which only consists of "surface" ? Isn't there a really huge impact of lattice relaxation which cannot be excluded or even estimated?
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