Vortex-like state observed in ferromagnetic contacts
2010 (English)In: Journal of Physics: Conference Series, ISSN 1742-6588, Vol. 200, no 5, 1-4 p.Article in journal (Refereed) Published
Point-contacts (PC) oﬀer a simple way to create high current densities, 109 A/cm 2and beyond, without substantial Joule heating. We have shown recently (Nano Letters, 7(2007) 927) that conductivity of nanosized PCs between a normal and ferromagnetic metalsexhibits bi-stable hysteretic states versus both bias current and external magnetic ﬁeld – theeﬀect typical for spin-valve structures. Here we report that apart from the bi-stable state athird intermediate-resistance state is occasionally observed. We interpret this state as due toa spin-vortex in the PC, nucleated either by Oersted ﬁeld of the bias current and/or by thecircular geometry of PC. The observed three-level-states in the PC conductivity testify that theinterface spins are both weakly coupled to the spins in the bulk and have depressed exchangeinteraction within the surface layer.
Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP), 2010. Vol. 200, no 5, 1-4 p.
vortex, spin valve, point contact, micromagnetism, spin, magnetic
Nano Technology Condensed Matter Physics Other Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-49331DOI: 10.1088/1742-6596/200/5/052033ISI: 000291321302077ScopusID: 2-s2.0-77957058180OAI: oai:DiVA.org:kth-49331DiVA: diva2:461355
QC 201112122011-12-122011-11-252011-12-12Bibliographically approved