Perpendicular Local Magnetization Under Voltage Control in Ni Films on Ferroelectric BaTiO₃ Substrates

Abstract

High‐resolution magnetoelectric imaging is used to demonstrate electrical control of the perpendicular local magnetization associated with 125 nm‐wide magnetic stripe domains in 100‐nm‐thick Ni films. This magnetoelectric coupling is achieved in zero magnetic field using strain from ferroelectric BaTiO3 substrates to control perpendicular anisotropy imposed by the growth stress. These findings may be exploited for perpendicular recording in nanopatterned hybrid media.

Cautions to predicate multiferroic by atomic force microscopy

“…To get more detailed information on atomic magnetic moments and local magnetic domains, X-ray magnetic circular dichroism (XMCD) and X-ray magnetic linear dichroism (XMLD) techniques [14][15][16] are usually used individually or combined with photoemission electron microscopy (PEEM) to provide a credible evidence. [17][18][19] Scanning Kerr Microscopy (SKM) based on magneto-optical Kerr effect (MOKE) 20,21 has also been utilized to detect electrically induced changes in local magnetic domains.…”

“…As a useful variant of AFM, magnetic force microscopy (MFM) 19,22 can be used to collect the local magnetic signal through the magnetic interaction between magnetic probe and the sample, so the distribution of the magnetic domains could be directly imaged. Compared to other methods, MFM takes the advantages of higher resolution due to the nanoscaled tip radius and 23 The influence of the disturbance is often eliminated by two-pass technique or electrostatic modulation.…”

Magnetically correlated anisotropic resistive switching manipulated by electric field in Co/PMN-PT heterostructures

“…With strong magnetoelectric coupling between the ferroelectric substrates and ferromagnetic layers, the control of magnetic and electronic transport properties by applying an electric field to the insulating ferroelectric substrate in multiferroic heterostructures has aroused great interests recently [1][2][3][4][5][6][7][8][9][10][11][12][13]. Several work have introduced the strain mediated variations of magnetic properties [6-8, 10, 12-16], electronic transport [17][18][19][20], Verway transition [21] and even spin-orbital coupling [22] in magnetoelectric heterostructures.…”

“…Several work have introduced the strain mediated variations of magnetic properties [6-8, 10, 12-16], electronic transport [17][18][19][20], Verway transition [21] and even spin-orbital coupling [22] in magnetoelectric heterostructures. The electric-field-controlled reversible magnetization rotation, which is important for practical applications in a wide range of low-power magnetic and spintronic devices [1,12], has been reported in Ni/0.7Pb(Mg 1/3 Nb 2/3 )O 3 -0.3PbTiO 3 [8,10,23] (Ni/PMN-PT) and CoFeB/PMN-PT [24] as well as the phase field simulations [8,12]. These magnetization rotations should naturally affect the electronic transport behaviors in the magnetic films [25][26][27][28].…”

Fast 180° magnetization switching in a strain-mediated multiferroic heterostructure driven by a voltage

“…Given that a time-invariant voltage cannot break the time-reversal symmetry of a magnetization, applying voltage alone typically induces an at most 90° magnetization switching. For example, piezostrain mediated6810 and exchange coupling mediated13 voltage-driven 90° magnetization switching have both been observed experimentally in multiferroic heterostructures at zero magnetic field. Such 90° switching provides basis for the design of low-power spintronic devices such as magnetoelectric random access memories (MeRAM), which integrate a magnetic tunnel junction (MTJ) on top of a ferroelectric/piezoelectric layer181920.…”