Nonvolatile, reversible electric-field controlled switching of remanent magnetization in multifunctional ferromagnetic/ferroelectric hybrids

Abstract

In spin-mechanics, the magnetoelastic coupling in ferromagnetic/ferroelectric hybrid devices is exploited in order to realize an electric-voltage control of magnetization orientation. To this end, different voltage-induced elastic strain states are used to generate different magnetization orientations. In our approach, we take advantage of the hysteretic expansion and contraction of a commercial piezoelectric actuator as a function of electrical voltage to deterministically select one of two electro-remanent elastic strain states. We investigate the resulting magnetic response in a nickel thin film/piezoelectric actuator hybrid device at room temperature, using simultaneous magnetooptical Kerr effect and magnetotransport measurements. The magnetic properties of the hybrid can be consistently described in a macrospin model, i.e., in terms of a single magnetic domain. At zero external magnetic field, the magnetization orientation in the two electro-remanent strain states differs by 15 , which corresponds to a magnetoresistance change of 0.5%. These results demonstrate that the spin-mechanics scheme indeed enables a nonvolatile electrically read-and writable memory bit where the information is encoded in a magnetic property.

Understanding and designing magnetoelectric heterostructures guided by computation: progresses, remaining questions, and perspectives

“…37,38,41,116,[180][181][182][183][184][185][186][187][188][189][190][191][192] We term these four types of converse magnetoelectric coupling mechanisms as 'charge densities', 'interfacial oxidation', 'exchange coupling', and 'strain transfer', respectively. Note that the change of magnetization (ΔM) can be global (that is, average of an entire heterostructure), which can be measured directly using, for example, a superconducting quantum interference device or indirectly from the Hall transport measurement; the ΔM can also represent the magnetization change within a local surface area (precisely, including surface regions within the probe depth) of the sample, which can be measured through various magnetic domain imaging techniques (see a summary in ref.…”

Converse magnetoelectric effects in Fe3O4/BaTiO3multiferroic hybrids

“…[1][2][3] The presence of such a cross-coupling between ordered magnetic and dielectric states in socalled multiferroic systems allows for the development of a new family of devices, where the spin degree of freedom is controlled by electric instead of magnetic fields. [4][5][6][7][8][9][10] It has been shown that a robust electric field control of magnetism can be realized by using extrinsic multiferroic hybrid structures consisting of ferroelectric and ferromagnetic materials. [11][12][13][14][15] In these systems, the extrinsic magnetoelectric effects rely on either electric field effects 16 using carrier mediated ferromagnets, 17 or employing exchange coupling effects between antiferromagnetic, ferroelectric and ferromagnetic compounds.…”

Optimization of indirect magnetoelectric effect in thin-film/substrate/piezoelectric-actuator heterostructure using polymer substrate

“…Artificial magnetoelectric systems seems to be a promising route for such control. The easiest artificial architecture for a magnetization voltage control in those kinds of materials appears to be the piezoelectric/magnetostrictive bilayers presenting a good strainmediated coupling at the interface [4][5][6][7][8][9][10][11][12]. However, in these systems, clamping effects due to the substrate limits the strain applicable by the piezoelectric environment to the magnetization and therefore reduces perspective on applications.…”