Diameter-modulated nanostructures

 

Controlling the motion of magnetic domain walls might allow for the implementation of a novel data storage platform, a more robust and less energy-intensive one than current hard drives based on magnetization. More specifically, micromagnetic and Monte Carlo simulations have shown the importance of domain wall structure in determining the behavior of the domain wall in regions where the width of the wire varies. Besides, diameter-modulated CoFe nanowires with diameters of 60/120nm were AC-pulse electrodeposited into highly ordered nanoporous anodic aluminium oxide templates. Furthermore, Ieda et al. have studied the influence of the nanowire modulation on DW motion induced by pulsed currents with use of the collective coordinate method. Sulka et al. fabricated various diameter-modulated metallic nanowires (Au, Ag, Ni and Ag-Au) by electrodeposition in the pores of anodic alumina membranes.

 

In this topic, we have investigated by analytical calculations, micromagnetic simulations and FORC curves, the magnetic properties of cylindrical diameter modulated permalloy nanowires [1,2]. In addition, we investigated the mechanism of magnetization reversal of nickel nanowires with modulated diameters [3]. In this last article we could perform the single-object characterization utilizing the magneto-optical Kerr effect magnetometry that showed a strong correlation between geometric parameters and magnetic properties. Finally, by using atomic layer deposition (ALD) we have performed the controlled introduction of diameter modulations in arrayed magnetic iron oxide nanotubes [4].

 

[1] F. Tejo, N. Vidal-Silva, A. P. Espejo, J. Escrig, Angular dependence of the magnetic properties of cylindrical diameter modulated Ni80Fe20 nanowires, Journal of Applied Physics 115, 17D136 (2014).

[2] Mohamed Shaker Salem, Philip Sergelius, Rosa M. Corona, Juan Escrig, Detlef Gorlitz, Kornelius Nielsch, Magnetic properties of cylindrical diameter modulated Ni80Fe20 nanowires: interaction and coercive fields, Nanoscale 5, 3941 (2013).

[3] Kristina Pitzschel, Julien Bachmann, Stephan Martens, Josep M. Montero-Moreno, Judith Kimling, Guido Meier, Juan Escrig, Kornelius Nielsch, Detlef Gorlitz, Magnetic reversal of cylindrical nickel nanowires with modulated diameters, Journal of Applied Physics 109, 033907 (2011).

[4] Kristina Pitzschel, Josep M. Montero-Moreno, Juan Escrig, Ole Albrecht, Kornelius Nielsch, Julien Bachmann, Controlled introduction of diameter modulations in arrayed magnetic iron oxide nanotubes, ACS Nano 3, 3463-3468 (2009).