Effect of Low Dimensionality and Encapsulation on the Magnetic and Hyperfine Properties of Iron Nanowires

Ab initio calculations were performed for a very thin iron nanowire, both free-standing and enclosed in a carbon nanotube with the same size and structure of available experiments. Our interest was to study the effects of low dimensionality and the influence of the Fe C interaction on the magnetic and hypefine properties of these systems. Our main finding was that the interfacial region between the nanowire and the carbon nanotube is of fundamental importance, as an iron atom close to the carbon atoms has a magnetic moment and a local hyperfine field very different from that at the surface of a free-standing iron nanowire. In fact, the properties of the calculated iron nanowire, of only 1 nm in diameter, when encapsulated inside a carbon nanotube result close to those of bulk iron.