  Cleaving crystals in a vacuum chamber is a simple method for obtaining
atomically flat and clean surfaces for materials that have a preferential
cleaving plane. Most in-situ cleavers use parallel cutting edges that are
applied from two sides on the sample. We found in ambient experiments that
diagonal cutting pliers, where the cleavage force is introduced in a single
point instead of a line work very well also for hard materials. Here, we
incorporate the diagonal cutting plier principle in a design compatible with
ultra-high vacuum requirements. We show optical microscopy (mm scale) and
atomic force microscopy (atomic scale) images of NiO(001) surfaces cleaved with
this device.
