Silicon-containing multidecker organometallic complexes and nanowires: A density functional theory study

Silicon-containing multidecker organometallic complexes and nanowires, Cr _n(SiBz) _m and V _n(SiBz) _m (SiBz = 1,3,5-silicon-substituted benzene), are predicted to possess novel electronic, magnetic, and electron transport properties by using density functional theory and nonequilibrium Greens function calculations. The multidecker complexes and nanowires are stabilized by the strong Cr-Si and V-Si interaction. It is found that the Cr _n(Bz) _m nanowire exhibits an antiferromagnetic ground state, while the V _n(SiBz) _m nanowire exhibits properties of a diluted magnetic semiconductor, contrary to the known quasi-half-metallic properties of the carbon analogue, V _n(Bz) _m complexes and nanowires. Between two metal electrodes, the finite-size V ₃(SiBz) ₄ complex not only possesses higher conductivity than Cr ₃(SiBz) ₄ but also exhibits a distinctive feature of negative differential resistance (NDR). In general, the minority spin channel of V ₃(SiBz) ₄ is the main transport channel at a relatively low voltage bias (<1.4 V), whereas under a relatively high bias (>1.6 V), both the majority and minority spin channels of V ₃(SiBz) ₄ become the main channel for electron transport. For the [V(SiBz)] _∞ nanowire, however, the majority spin channel becomes the main channel for electron transport.