Area Partitions in Magnetic Nanowires

Magnetic domains partitions are identified to be a supply {of electrical} resistance because of the issue for transport electron spins to observe their magnetic texture. This phenomenon holds potential for utilization in spintronic gadgets, the place {the electrical} resistance can range based mostly on the presence or absence of a website wall. A very intriguing class of supplies are half metals reminiscent of La2/3Sr1/3MnO3 (LSMO) which current full spin polarization, permitting their exploitation in spintronic gadgets. Nonetheless the resistance of a single area wall in half metals remained unknown. Now a workforce from Spain, France and Germany has generated a single area wall on a LSMO nanowire and measured resistance modifications 20 occasions bigger than for a traditional ferromagnet reminiscent of Cobalt.

Magnetic delicate PEEM pictures obtained at HZB: a) XAS picture of the crossed nanowires. X-ray beam and magnetic subject are aligned alongside the nanowire(vertical) course (inexperienced arrow). b-f) XMCD pictures of the cross for various utilized fields. Picture Credit score: © HZB

The magnetic area texture inherent to magnetic area partitions holds potential for spintronic purposes. {The electrical} resistance in ferromagnets depends upon whether or not area partitions are or not current. This binary impact (often called area wall magnetoresistance) could possibly be used to encode data in spintronic reminiscence gadgets. But, their exploitation is hindered because of the small modifications in resistance noticed for regular ferromagnets. A very attention-grabbing class of supplies are manganite perovskites reminiscent of La2/3Sr1/3MnO3 (LSMO). These compounds current just one sort of spin (full spin polarization) which might doubtlessly result in area wall magnetoresistance results giant sufficient to be exploited in a brand new technology of spintronic sensors and injectors.

Regardless of this promising perspective, there exist giant discrepancies within the reported values of the area wall magnetoresistance for this technique. The scientists from Spain, France and Germany have fabricated nanowire-based gadgets enabling the nucleation of particular person magnetic area partitions. Magneto transport measurements in these gadgets present that the presence of a website wall results in a rise of {the electrical} resistance of as much as 12%. In absolute phrases, the noticed resistance change is 20 occasions bigger than that reported for Cobalt.

This work is the results of a longstanding collaboration which entails movie development and nanofabrication, transport measurements, contact microscopy (MFM) imaging, theoretical simulations and using superior characterization strategies reminiscent of X-ray photoemission electron microscopy. The mixture of all kinds of various strategies offers a complete multi-facet view of a posh downside which has allowed to succeed in new insights right into a extremely debated open query.


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