Tuning the spin-related transport properties of FePc on Au(111) through single-molecule chemistry

Abstract

Tuning the spin-dependent electron transport through molecules is of fundamental importance in single-molecule spintronics. Here, the transport properties of iron phthalocyanine on Au(111) was investigated by a combination of scanning tunneling microscopy and density functional theory calculations. Using high-resolution scanning tunneling spectroscopy performed at 0.5 K, a Kondo resonance was observed on FePc. After removing its eight outermost hydrogen atoms, the spectroscopic feature changed into a double-step structure, which reflected inelastic transitions of molecular spin states. The density functional theory calculations revealed that the coupling between Fe and Au(111) became much weaker after cutting the hydrogen atoms. This explained the change of the spin-related fingerprints in the differential spectra.

Precise Control of π-Electron Magnetism in Metal-Free Porphyrins

“…The rich functionalities of porphyrin complexes orginate from the center macrocycle, which can stablize a variety of elements inside and thus gives rise to distinct structural, electronic, magnetic, optoelectronic, and transport properties [4][5][6][7][8][9][10][11][12][13] . Magnetic metalloporphyrins have been extensively studied by various techniques, exhiting kondo and spin excitation effects, Yu-Shiba bound states, and spin-state switching [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] . Recently, hybridized graphene and metalloporphyrin nanostructures have been achieved, hosting combined intriguing electronic and magnetic properties [28][29][30][31][32][33] .…”

Chemical Synthesis at Surfaces with Atomic Precision: Taming Complexity and Perfection

“…A clear Kondo resonance and a high Kondo temperature of 200 K were observed. The dehydrogenation threshold voltage applied was found in the range of 3.3 V to 3.5 V. In the case of a FePc molecule adsorbed on Au(111), cutting away its eight outermost hydrogen atoms by applying a −3.5 V voltage pulse turned off the Kondo effect . The formation of the chemical bonds between the dehydrogenated CoPc molecule and Au atoms of the surface increased the distance between the Fe 2+ ion and the Au atoms, thereby weakening the Fe–Au coupling.…”

“…Thedehydrogenation threshold voltage applied was found in the range of 3.3 Vto3.5 V. In the case of aF ePc molecule adsorbed on Au(111), cutting away its eight outermost hydrogen atoms by applying a À3.5 Vv oltage pulse turned off the Kondo effect. [59] Thef ormation of the chemical bonds between the dehydrogenated CoPc molecule and Au atoms of the surface increased the distance between the Fe 2+ ion and the Au atoms,thereby weakening the Fe-Au coupling.C onsequentially,t he molecule changed from the Kondo state to the magnetic triplet state.K im et al demonstrated that the spin state of Co-porphyrin on Au(111) could be reversibly switched by binding and releasing the NO molecule. [60] TheK ondo effect was switched off by the formation of the coordination complex NO-Co-porphyrin, and could be switched back on by removing the NO by local manipulation or thermal desorption (at 500 K).…”

Endohedral Fullerene Fe@C28 Adsorbed on Au(111) Surface as a High-Efficiency Spin Filter: A Theoretical Study

“…Molecular spintronics has attracted tremendous attentions due to its promising applications in nanoelectronics in the past few years [1,2,3,4,5,6]. The conductance can be directly controlled by the spin degrees of freedom in a single molecule.…”