PREPARATION BY ION MILLING AND TEM INVESTIGATION OF EMBEDDED NEEDLE-SHAPED CRYSTALS OF H-NB2O5

A method for preparing needle-shaped and platelike crystals for electron microscopical investigation was elaborated. Crystals of H-Nb2O5 were embedded in a synthetic resin and disks were cut off perpendicular to the desired direction of observation. The thickness of the sample was reduced by planar grinding and then by using a dimple grinder and furthermore by ion milling with argon ions. With the precision ion milling system small crystal areas were selected and subsequently irradiated. The TEM investigations showed that the desired crystallographic orientation was reached and that the crystal structure has been preserved. The contrast of highly resolved images was reduced by an amorphous surface layer which was not removable.