Naslov
Field dependence of the magnetic switching induced by a spin polarized current: a probe for theoretical models

Autori
Grollier, Julie ; Cros, Vincent ; Jaffres, Henry ; Hamzić, Amir ; George, Jean-Marie ; Faini, Giancarlo , Ben Youssef, J. ; Le Gall, H. ; Fert, Albert

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
47th Annual Conference on Magnetism & Magnetic Materials MMM'02, / - Tampa (FL), 2002

Skup
47th Annual Conference on Magnetism & Magnetic Materials

Mjesto i datum
Tampa (FL), Sjedinjene Američke Države, 11.11.2002. - 15.11.2002

Vrsta sudjelovanja
Plenarno

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
spintronics; magnetization reversal mechanisms; magnetic properties of interfaces (multilayers; superlattices; heterostructures); electronic transport in interface structures

Sažetak
We present experimental results on the magnetization reversal driven by a spin polarized current in pillar-shaped Co (15nm)/Cu (10 nm)/Co (2.5 nm) trilayers. Besides experiments performed at zero field in agreement with previous results on similar pillars, we also study the field dependence of the critical currents and clearly evidence the existence of two regimes according to the amplitude of the applied field H_appl compared to an anisotropy field H_an. For H_appl < H_an, the reversals from parallel to antiparallel and vice versa, are sharp as the respective critical currents are reached and the resulting R(I) curve is hysteretic. For H_appl > H_an, the reversals are much smoother and fully reversible. Up to now, two theoretical approaches have been proposed in order to calculate the current induced torque. The model based on a direct interaction between the magnetic moment carried by the conduction electrons and the local magnetization is unable to explain even qualitatively these later results. On the contrary, we are able to interpret them correctly in the frame of the spin transfer model using a diffusive approach. We calculate in detail the spin polarization of the conduction electron using the Valet-Fert model developed for the CPP-GMR and the critical currents extracted from the Landau-Lifschitz-Gilbert equation in presence of an external applied field. The comparison with our experimental results leads us to the conclusion that only the spin transfer approach is able to describe properly the properties of the spin current induced magnetization reversal.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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