Scanning tunneling microscopy investigation of substrate-dependent adsorption and assembly of metallofullerene Gd@C₈₂ on Cu(111) and Cu(100)

The structural and electronic properties of Gd@C₈₂ adsorbed on Cu(111) and Cu(100) surfaces were investigated by scanning tunneling microscopy (STM). STM images showed that the lattice structure of the underlying metal substrates affected the arrangement of the metallofullerene molecules. Preferred adsorption orientations of the molecules were found from STM images with submolecular resolution. Differences in the scanning tunneling spectroscopy of molecules adsorbed on Cu(111) and Cu(100) were observed and attributed to the work function difference between the substrates. In addition, the electronic properties of the fullerene monomer, dimer, and monolayer were characterized and compared, revealing the roles played by the molecule-substrate interaction and the intermolecular interaction.