Strain-assisted magnetization reversal in Co/Ni multilayers with perpendicular magnetic anisotropy

Abstract

Multifunctional materials composed of ultrathin magnetic films with perpendicular magnetic anisotropy combined with ferroelectric substrates represent a new approach toward low power, fast, high density spintronics. Here we demonstrate Co/Ni multilayered films with tunable saturation magnetization and perpendicular anisotropy grown directly on ferroelectric PZT [Pb(Zr0.52Ti0.48)O3] substrate plates. Electric fields up to ±2 MV/m expand the PZT by 0.1% and generate at least 0.02% in-plane compression in the Co/Ni multilayered film. Modifying the strain with a voltage can reduce the coercive field by over 30%. We also demonstrate that alternating in-plane tensile and compressive strains (less than 0.01%) can be used to propagate magnetic domain walls. This ability to manipulate high anisotropy magnetic thin films could prove useful for lowering the switching energy for magnetic elements in future voltage-controlled spintronic devices.

Routes to Low-Energy Magnetic Electronics

“…The idea of Strain-assisted Recording, [33][34][35] (called in analogy to Heat-Assisted Magnetic Recording) was to facilitate the writing information in magnetic media by reducing the magnetic anisotropy by strain. This principle can be implemented on the basis of composite magnetoelectric materials 36 : the magnetic layer on piezoelectric substrate [ Fig.…”

Strain engineered domain structure and their relaxation in perpendicularly magnetized Co/Pt deposited on flexible polyimide

“…Miniaturization and flexibility with high speed and low power consumption are the key aspects for developing next generation spintronic devices [1][2][3]. Perpendicular magnetic anisotropic (PMA) systems such as Co/Pt bilayes have shown their importance in increasing thermal stability and developing non-volatile magnetic random access memories (MRAM's) with low current density requirement for magnetization switching at 20 nm bit size level [1,[4][5][6][7][8][9]. The major challenge in further downscaling of devices is the higher power dissipation [10].…”

Electric-Field-Enhanced Bulk Perpendicular Magnetic Anisotropy in GdFe/Pb(Mg1/3Nb2/3)0.7Ti0.3O3 Multiferroic Heterostructure

“…[21][22][23][24][25] Recently, electric-field control of PMA using multiferroic heterostructures has been reported. [26][27][28][29][30][31][32][33][34][35][36][37][38] For example, Sun el al. 34 and Peng et al 35 demonstrated electric-field control of spin reorientation transition (SRT) and interface PMA in (Co/Pt) 3 /PMN-PT (Pb(Mg 1/3 Nb 2/3 ) 0.7 Ti 0.3 O 3 ) multiferroic heterostructure.…”

“…; 32 thus, we measured the AHE under in situ electric fields to study the effect of the ferroelectric substrate with Co/Pt multilayers, 34,35,37,38 CoPd alloy, 26,27 Cu/Ni multilayers, 36 Co/Ni multilayers 33 and so on. Moreover, the magnetic materials in the literature are ferromagnetic, while the GdFe film in the current study is ferrimagnetic.…”