Effect of angular dependence of spin-transfer torque on zero-field microwave oscillation in symmetric spin-valves

Seo Won Lee, Kyung Jin Lee

    Research output: Contribution to journalArticlepeer-review

    11 Citations (Scopus)

    Abstract

    We numerically investigate effect of the angular dependence of spin-transfer torque (STT) on current-induced precession mode in symmetric spin-valve structures where two ferromagnets are free to move. Two spin-valve structures with NiFe and Co as ferromagnets are studied, which show considerably different angular dependence of STT. We find that the zero-field microwave oscillation occurs in symmetric spin-valve structures. Precession frequency can reach around 10 GHz and decreases with increasing current. In contrast to a spin-valve structure with a single free layer, the blue shift is not observed due to highly nonlinear coupling of two magnetizations. We find that more symmetric angular dependence of STT allows the magnetic excitation at a lower current and provides a more monotonous increase of output power.

    Original languageEnglish
    Article number5467630
    Pages (from-to)2349-2352
    Number of pages4
    JournalIEEE Transactions on Magnetics
    Volume46
    Issue number6
    DOIs
    Publication statusPublished - 2010 Jun

    Bibliographical note

    Funding Information:
    This work was supported by the Degree of Research Center (DRC) Program funded by the Korea Research Council of Fundamental Science and Technology (KRCF).

    Keywords

    • Diffusive transport
    • Microwave oscillation
    • Spin transfer torque

    ASJC Scopus subject areas

    • Electronic, Optical and Magnetic Materials
    • Electrical and Electronic Engineering

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