Spin Interactions of On-surface Grown Metal Organic Structures Studied Using Scanning Tunneling Microscopy

On-surface synthesis attracts much attention because it provides a facile way to prepare various molecular structures such as graphene nano-ribbons, chiral supramolecular networks, and metal-organic structures in ultrahigh vacuum. The metal organic molecular structures often have spin-spin interactions that can be used for molecular spintronics and quantum information science, but were rarely probed at the atomic level. Here, we report on the atomic, electronic, and spin structures of metal-organic structures of 2,3,6,7,10,11-Hexahydroxytriphenylene (HHTP) and Ni studied using scanning tunneling microscopy (STM). The metal-organic structures were prepared by on-surface synthesis on Au(111) and showed several different structures that can be explained by O – Ni – O bonds. Strong zero bias peaks were observed implying spin-spin interactions between d-orbitals of Ni and conduction electrons of surfaces. Our study shows that on-surface grown metal-organic structures provide excellent platform for studying spin-spin interactions.