Urbaniak M, Kiphart D, Matczak M, Stobiecki F, Chaves-O'Flynn GD, Kuświk P. Ferrimagnetic Tb/Co multilayers patterned by ion bombardment as substrates for magnetophoresis.
Sci Rep 2024;
14:23771. [PMID:
39390021 PMCID:
PMC11467345 DOI:
10.1038/s41598-024-73203-3]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 09/16/2024] [Indexed: 10/12/2024] Open
Abstract
Ion bombardment with 30 keV Ga+ ions can locally change the magnetic properties of perpendicular magnetic anisotropy ferrimagnetic Tb/Co based multilayers. The induced changes in the effective magnetization create high gradients of magnetic fields in the proximity of the perimeters of the bombarded areas. Superparamagnetic, micrometer-sized beads floating in an aqueous suspension over such a patterned structure respond to the ensuing magnetostatic energy landscape. This landscape, and its associated forces on the beads, can be controlled with a time varying, external, homogeneous magnetic field. It is shown that with a 3.37 kA/m (approx. 4.2 mT) field and switching the direction at 10 Hz frequencies the beads can be driven with average forward velocities reaching 40 μ m/s. This has the potential for use in lab-on-a-chip type assays.
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