Low Temperature Physics: 35, 693 (2009); https://doi.org/10.1063/1.3224728 (9 pages)
Fizika Nizkikh Temperatur: Volume 35, Number 8-9 (August 2009), p. 879-890    ( to contents , go back )

Nonstationary magnetization dynamics in point contacts with single ferromagnetic film

O.P. Balkashin, I.K. Yanson, V.V. Fisun, L.Yu. Triputen

B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Lenin Ave., Kharkov 61103, Ukraine
E-mail: Balkashin@ilt.kharkov.ua

A. Konovalenko and V. Korenivski

Nanostructure Physics, Royal Institute of Technology, Stockholm SE-10691, Sweden
pos Анотація:

Received March 5, 2009

Abstract

The electrical conduction of point nanocontacts between ferromagnetic cobalt films 5, 10 and 100 nm thick and a nonmagnetic metal (copper or silver) needle has been investigated. Two fundamentally different mechanisms of response to microwave irradiation have been detected for the first time. One mechanism is the effect of rectification of HF alternating current on the nonlinearity of the I–V characteristic due to the transport direct current through the contact. The other is related to the external HF field-induced excitation of the resonant magnetization precession at the main frequency and its harmonics. The experimental results support our previous conclusion [Nano Letters 7, 927 (2007)] that a «surface spin valve» is realized in the investigated F–N nanocontacts and has statical and dynamical properties similar to those of the standard spin valve F1–N–F2.

PACS: 72.25.–b Spin polarized transport;
PACS: 73.40. Jn Metal-to-metal contacts;
PACS: 75.75.+a Magnetic properties of nanostructures;
PACS: 85.75.–d Magnetoelectronics; spintronics.

Key words: point contact, spin-torque transfer, magnetization precession, microwave irradiation.

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