  Aspects of transmission electron goniometry are discussed. Combined with high
resolution phase contrast transmission electron microscopy (HRTEM) and atomic
resolution scanning TEM (STEM) in the atomic number contrast (Z-STEM) or the
phase contrast bright field mode, transmission electron goniometry offers the
opportunity to develop dedicated methods for the crystallographic
characterization of nanocrystals in three dimensions. The relationship between
transmission electron goniometry and electron tomography for materials science
applications is briefly discussed. Internet based java applets that facilitate
the application of transmission electron goniometry for cubic crystals with
calibrated tilt-rotation and double-tilt specimen holders/goniometers are
mentioned. The so called cubic-minimalistic tilt procedure for the
determination of the lattice parameters of sub-stoichiometric WC1-x
nanocrystals with halite structure is demonstrated. The freely (openly)
accessible, Internet based, Crystallography Open Database (COD) is briefly
discusses because the ability to determine the lattice parameters of
nanocrystals opens up the possibility of identifying unknown phases by
comparing these lattice constants to the entries of comprehensive databases.
Correspondingly, a search of the determined lattice parameters in the COD is
shown as part of a screen shot. The enhanced viability of transmission electron
goniometry in TEMs (and STEMs) with aberration corrected electron optics is
illustrated on the WC1-x model system.
