Thermoelectrical manipulation of nanomagnets
Artikel i vetenskaplig tidskrift, 2010

We investigate the interplay between the thermodynamic properties and spin-dependent transport in a mesoscopic device based on a magnetic multilayer (F/f/F), in which two strongly ferromagnetic layers (F) are exchange-coupled through a weakly ferromagnetic spacer (f) with the Curie temperature in the vicinity of room temperature. We show theoretically that the Joule heating produced by the spin-dependent current allows a spin-thermoelectronic control of the ferromagnetic-to-paramagnetic (f/N) transition in the spacer and, thereby, of the relative orientation of the outer F-layers in the device (spin-thermoelectric manipulation of nanomagnets). Supporting experimental evidence of such thermally-controlled switching from parallel to antiparallel magnetization orientations in F/f(N)/F sandwiches is presented. Furthermore, we show theoretically that local Joule heating due to a high concentration of current in a magnetic point contact or a nanopillar can be used to reversibly drive the weakly ferromagnetic spacer through its Curie point and thereby exchange couple and decouple the two strongly ferromagnetic F-layers. For the devices designed to have an antiparallel ground state above the Curie point of the spacer, the associated spin-thermionic parallel to antiparallel switching causes magnetoresistance oscillations whose frequency can be controlled by proper biasing from essentially dc to GHz. We discuss in detail an experimental realization of a device that can operate as a thermomagnetoresistive switch or oscillator.

spin-dependent transport

thermomagnetoresistive oscillator

nanomagnets

Författare

Anatoli M. Kadigrobov

Göteborgs universitet

Stefan Andersson

Danko Radic

Göteborgs universitet

Robert I. Shekhter

Göteborgs universitet

Mats Jonson

Göteborgs universitet

V. Korenivski

Journal of Applied Physics

0021-8979 (ISSN) 1089-7550 (eISSN)

Vol. 107 12 123706-

Ämneskategorier

Den kondenserade materiens fysik

DOI

10.1063/1.3437054