Current induced vortices in multi-nanocontact spin-torque devices
2011 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 109, no 7, 07C913- p.Article in journal (Refereed) Published
We demonstrate spin transfer torque (STT) switching in multi-nanocontact STT devices fabricated using hole mask colloidal lithography. We also study the STT device resistance and switching properties as a function of applied magnetic field and nanocontact current. At low nanocontact current, magnetoresistance measurements show sharp, single-step switching at low switching fields. When the current is increased, the switching becomes multistep, and the switching field increases dramatically. We explain these results as arising from a transition from a predominantly single domain like switching to switching involving a vortex state. Micromagnetic simulations corroborate this picture, indicating that a single magnetic vortex nucleates in between the nanocontacts through the influence from the total Oersted field generated by the nanocontact ensemble.
Place, publisher, year, edition, pages
2011. Vol. 109, no 7, 07C913- p.
IdentifiersURN: urn:nbn:se:kth:diva-35134DOI: 10.1063/1.3556960ISI: 000289952100158ScopusID: 2-s2.0-79955442839OAI: oai:DiVA.org:kth-35134DiVA: diva2:426429
QC 201106232011-06-232011-06-202013-05-27Bibliographically approved