Formation and Kinetics of Self-Assembled Structures of Magnetic Microparticles in Rotating Fields

• Published in: IEEE transactions on magnetics Vol. 49; no. 8; pp. 4725 - 4728
• Main Authors: Llera, Maria, Codnia, Jorge, Jorge, Guillermo A.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.08.2013; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Biaxial fields; Coils; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; image analysis; Iron; magnetic particles; Magnetic resonance imaging; Magnetism; Magnetoelasticity; Materials science; Nickel; Other topics in materials science; Perpendicular magnetic anisotropy; Physics; self-assembled structures; Image analysis; Magnetic powder; Magnetic field effects; Kinetics; Biaxial fields; Magnetic fields; magnetic particles; self-assembled structures; Magnetic properties
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2013.2257166

We study the formation of self-assembled structures of magnetic microparticles subjected to the action of a biaxial alternating field. The used device comprises a set of two nested orthogonal Helmholtz coils that can produce rotating fields in the horizontal plane by applying proper alternating currents to the coils. In this way, it is possible to induce a planar organization in a set of magnetic micrometer-size Fe and Ni particles dispersed in a liquid. We investigate, by means of video-microscopy image analysis performed in the MATLAB environment, the time evolution of topological parameters, as the number of objects detected. We also investigate the circularity of the dominant object at different stages of the structure formation and the region of power-law behavior of the time evolution. We compare the characteristic times for pattern formation under different field configurations.