Dynamics of Current Induced Magnetic Superstructures in Exchange-Spring Devices

Abstract

Thermoelectric manipulation of the magnetization of a magnetic layered stack in which a low-Curie temperature magnet is sandwiched between two strong magnets (exchange spring device) is considered. Controllable Joule heating produced by a current flowing in the plane of the magnetic stack (CIP configuration) induces a spatial magnetic and thermal structure along the current flow --- a magneto-thermal-electric domain (soliton). We show that such a structure can experience oscillatory in time dynamics if the magnetic stack is incorporated into an electric circuit in series with an inductor. The excitation of these magneto-thermionic oscillations follow the scenario either of "soft" of "hard" instability: in the latter case oscillations arise if the initial perturbation is large enough. The frequency of the temporal oscillations is of the order of $10^5÷10^7{s}^{-1}$ for current densities $j\sim 10^6÷10^{7}A/c{m}^3$.

8 pages, 5 figures

References in corpus (5)

• Spin Transfer Torques
• Anisotropy Dependence of Irreversible Switching in Fe/SmCo and FeNi/FePt Exchange Spring Magnet Films
• Thermoelectrical manipulation of nanomagnets
• Spectroscopy of phonons and spin torques in magnetic point contacts
• Joule Heating and Current-Induced Instabilities in Magnetic Nanocontacts