Study on the spin-crossover transition in [Fe(cis-/trans-stpy)4(X)2] (stpy: styrylpyridine, X: NCS, NCBH3) under high pressure toward ligand-driven light-induced spin change

Transport property of ligand-driven light-induced spin-change Fe-based spin crossover complexes

The Fe-based spin-crossover (SCO) complexes, especially the ligand-driven light-induced spin-change (LD-LISC) systems with high spin-transition temperature, are considered as the most promising building blocks for designing molecular spintronic devices due to their bistability between the high-spin (HS) and low-spin (LS) states. Here, we explore the transport properties of Fe(stpy)₄(NCS)₂ LD-LISC SCO complexes with the trans and cis configurations sandwiched between Au electrodes by performing extensive density functional theory calculations combined with the non-equilibrium Green's function method. As for the trans configuration, the current through the molecular junction with the HS state is significantly larger than that of the LS state, which indicates that this Fe-based LD-LISC SCO complex with the trans configuration could act as a molecular switch when the spin transition is triggered by external stimuli. Remarkably, we observe the nearly perfect spin-filtering effect and obvious negative differential resistance feature in the Fe(stpy)₄(NCX)₂ junctions with the trans and cis configurations, which is attributed by the dramatically different electronic structures of two spin channels and the bias-dependent transmission spectra, respectively. These obtained theoretical findings suggest that the examined Fe-based LD-LISC SCO complexes hold great potential in molecular spintronics.

The transport properties of LD-LISC Fe-based SCO complexes with the trans and cis configuration exhibit robust spin-filtering and NDR features, which highlight them for promising applications in molecular devices.

Study of pressure influence on thermal transition in spin-crossover nanomaterials

The thermal transition accompanied by the variation of the molecular volume in nanoparticles of spin-crossover materials has been studied on the basis of microscopic Ising-like model solved using Monte Carlo methods. For considered model, we examined the spin-crossover phenomenon with applied hydrostatic pressure and thus was shown the possibility to shift transition temperature toward its room value. The obtained results of numerical simulations are in agreement with the experimental ones.