Abstract:
We have investigated the cleaving behavior of potassium bichromate (K₂Cr₂O₇) crystals using atomic force microscopy. This crystal has a double layered AB
structure along (001). We find that, upon cleavage along the (001) plane in he (100) directions, one side is completely A terminated, while the other is B terminated.
Moreover, the cleavage plane (between an A and a B layer, or between B and A) depends on the imposed direction of cleavage, i.e.. [100] or [(1) over bar 00].
This means that the molecular layer that terminates the crystal surface can be controlled by choosing the macroscopic direction of the cleavage force. One of the two
terminations is metastable and partly reconstructs to the stable termination.