Charge-Transfer-Based Mechanism for Half-Metallicity and Ferromagnetism in One-Dimensional Organometallic Sandwich Molecular Wires

摘要

We present a systematic theoretical study on the mechanism of half-metallicity and ferromagnetism for one-dimensional (1-D) sandwich molecular wires (SMWs) constructed with altering cyclopen-tadienyl (Cp) and first-row transition metal (Mt). It is unveiled for the first time that, in (MtCp)_∞, one valence electron would transfer from the Mt to the Cp ring, forming Cp~- and Mt~+ altering structures. This electron transfer not only makes them more stable than the benzene analogues (MtBz)_∞ but also leads to completely different half-metallic and ferromagnetic mechanisms. We analyze such unusual half-metallicity and ferromagnetic behaviors and explain each SMW magnetic moment quantitatively. Finally, we indicate that a Peierls transition does not occur in these 1-D SMWs.