Controlling the Spin States of FeTBrPP on Au(111)

Spin-flip excitations of iron porphyrin molecules on Au(111) are investigated with a low-temperature scanning tunneling microscope. The molecules adopt two distinct adsorption configurations on the surface that exhibit different magnetic anisotropy energies. Density functional theory calculations show that the different structures and excitation energies reflect unlike occupations of the Fe 3d levels. We demonstrate that the magnetic anisotropy energy can be controlled by changing the adsorption site, the orientation, or the tip-molecule distance.

Automated summary

Spin-flip excitations of iron porphyrin molecules on Au(111) were investigated using a low-temperature scanning tunneling microscope. The molecules exhibited two distinct adsorption configurations on the surface, with different magnetic anisotropy energies. Density functional theory calculations showed that the different structures and excitation energies were a result of different occupations of the Fe 3d levels. We demonstrated that the magnetic anisotropy energy could be controlled by changing the adsorption site, orientation, or tip-molecule distance.