Initial results from an ultrahigh-vacuum (UHV) third-order spherical
aberration (Cs) corrector for a dedicated scanning transmission electron
microscopy, installed at the National Institute for Materials Science,
Tsukuba, Japan, are presented here. The Cs corrector is of the dual
hexapole type. It is UHV compatible and was installed on a UHV column. The
Ronchigram obtained showed an extension of the sweet spot area, indicating
a successful correction of the third-order spherical aberration Cs. The
power spectrum of an image demonstrated that the resolution achieved was
0.1 nm. A first trial of the direct measurement of the fifth-order
spherical aberration C5 was also attempted on the basis of a
Ronchigram fringe measurement.