arXiv subjects

Vito Puliafito

Publications and source records attributed to Vito Puliafito.

20 records · Page 2Linked to original sources

arXiv2014

Switching Properties in Magnetic Tunnel Junctions with Interfacial Perpendicular Anisotropy: Micromagnetic Study

The role of universal memory can be successfully satisfied by magnetic tunnel junctions (MTJs) where the writing mechanism is based on spin-transfer torque (STT). An improvement in the switching properties (lower switching current density maintaining the thermal stability) has been achieved in MTJs with interfacial perpendicular anisotropy (IPA) at the interface between CoFeB and MgO. In this paper, micromagnetic simulations point out the influence of IPA and saturation magnetization (MS) on the properties of fast magnetization reversal achieved in 5, 10 and 20 ns. Both cases of in-plane and out-of-plane free layer are considered. In addition, the thermal effect is included for the in-plane switching at 20 ns and a complete analysis of energy dissipation during the switching is illustrated. This study can provide useful information for the design of STT-based memories.

cond-mat.mes-hall↗

arXiv2012

Power and linewidth of propagating and localized modes in nanocontact spin-torque oscillators

Integrated power and linewidth of a propagating and a self-localized spin wave modes excited by spin-polarized current in an obliquely magnetized magnetic nanocontact are studied experimentally as functions of the angle $θ_e$ between the external bias magnetic field and the nanocontact plane. It is found that the power of the propagating mode monotonically increases with $θ_e$, while the power of the self-localized mode has a broad maximum near $θ_e = 40$ deg, and exponentially vanishes near the critical angle $θ_e = 58$ deg, at which the localized mode disappears. The linewidth of the propagating mode in the interval of angles $58<θ_e<90$ deg, where only this mode is excited, is adequtely described by the existing theory, while in the angular interval where both modes can exist the observed linewidth of both modes is substantially broadened due to the telegraph switching between the modes. Numetical simulations and an approximate analytical model give good semi-quantitative description of the observed results.

cond-mat.mes-hall↗