Field emission and ion microscopy about cloverleaf pattern

The cloverleaf patterns could be observed in both FEM and FIM measurements. With pentacene, only two-lobe appeared. On the other hand, four-lobe patterns could be observed with both CuPc and GRANN. And especially in the case of FIM, image gases landed the on surface at first and were ionized by an electric field, so that FIM images must reflect surface electron state such as tunneling probability or electron states, molecules orbits and so on. This paper submitted the important facts to solve the origin of cloverleaf patterns formation mechanism. Unfortunately, they were not enough to clear perfectly. It was still remained mysterious how to form the clover leaf patterns in FEM and FIM.