Thermoelectrical manipulation of nanomagnets

Scientific paper - Original scientific paper

• Author: Anatoli Kadigrobov
• Author: Sebastian Andersson
• Author: Danko Radić
• Author: Robert Shekhter
• Author: Mats Jonson
• Author: Vladislav Korenivski
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

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.

• Keywords (english): exchange-spring; Curie temperature; ferromagnetic materials; ferromagnetic-paramagnetic transitions; magnetic multilayers; magnetoresistance; nanomagnetics; GMR; self-excited oscillations
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Journal of Applied Physics
• Numbering: vol. 107, 123706
• p-ISSN: 0021-8979
• e-ISSN: 1089-7550
• DOI: https://doi.org/10.1063/1.3437054
• URN:NBN: urn:nbn:hr:217:269812
• Publication: 2010
• Project: Number: 119-1191458-1023; Title (croatian): Sustavi s prostornim i dimenzijskim ograničenjima: korelacije i spinski efekti; Leader: Amir Hamzić; Jurisdiction: Croatia; Funding stream: ZP
• Document URL: http://dx.doi.org/10.1063/1.3437054
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright (2010) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
• Created on: 2019-11-01 19:09:13