Magnetic Nanowires


National Science Foundation Award #DMR-0906957


Devices based on manipulating and sensing both the charge and spin of electrons in a nanoscale system offer the combined advantages of high density, high speed, and non-volatility. The realization of these advantages have spurred research in the field of nanomagnetism, which is focused on understanding the complex behavior of electron spins, magnetic domains, and reversal in nanometer scale magnetic materials and devices. Towards the goal of understanding magnetism in confined dimensions, we have synthesized and characterized single-crystal Ni(001) nanowires fabricated by chemical vapor deposition. We have developed a single-step route for the reduction-type synthesis of nanostructured Ni materials. By tuning the CVD growth parameters, we can controllably synthesize morphologically dissimilar Ni products including single-crystal cubes and horizontally- and vertically-oriented NW arrays which form atop untreated amorphous SiO2||Si substrates. Micromagnetic simulations reveal that the competing anisotropies in single-crystal Ni nanowires result in surprising and complex domain structures, interesting magneto-transport properties and novel reversal modes not typically observed in magnetic nanowires. Experimental verification of these predicted structures is offered through magnetometry, transport measurements, and magnetic imaging through synchrotron radiation techniques.

Nanostructured Magnetic Materials_051311 Thesis on magnetic nanowires