Nearly Perfect Spin Filter, Spin Valve and Negative Differential Resistance Effects in a Fe4-based Single-molecule Junction

• Published in: Scientific reports Vol. 4; no. 1; p. 4838
• Main Authors: Zu, Fengxia, Liu, Zuli, Yao, Kailun, Gao, Guoying, Fu, Huahua, Zhu, Sicong, Ni, Yun, Peng, Li
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 02-05-2014; Nature Publishing Group
• Subjects: 147/136; 147/143; 639/301/1005/1007; 639/766/1130/2798; 639/925/927/998; Humanities and Social Sciences; Ligands; multidisciplinary; Science
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep04838

The spin-polarized transport in a single-molecule magnet Fe
4
sandwiched between two gold electrodes is studied, using nonequilibrium Green's functions in combination with the density-functional theory. We predict that the device possesses spin filter effect (SFE), spin valve effect (SVE) and negative differential resistance (NDR) behavior. Moreover, we also find that the appropriate chemical ligand, coupling the single molecule to leads, is a key factor for manipulating spin-dependent transport. The device containing the methyl ligand behaves as a nearly perfect spin filter with efficiency approaching 100% and the transport is dominated by transmission through the Fe
4
metal center. However, in the case of phenyl ligand, the spin filter effect seems to be reduced, but the spin valve effect is significantly enhanced with a large magnetoresistance ratio, reaching 1800%. This may be attributed to the blocking effect of the phenyl ligands in mediating transport. Our findings suggest that such a multifunctional molecular device, possessing SVE, NDR and high SFE simultaneously, would be an excellent candidate for spintronics of molecular devices.