Probing the local strain-mediated magnetoelectric coupling in multiferroic nanocomposites by magnetic field-assisted piezoresponse force microscopy

Abstract

The magnetoelectric effect that occurs in multiferroic materials is fully described by the magnetoelectric coupling coefficient induced either electrically or magnetically. This is rather well understood in bulk multiferroics, but it is not known whether the magnetoelectric coupling properties are retained at nanometre length scales in nanostructured multiferroics. The main challenges are related to measurement difficulties of the coupling at nanoscale, as well as the fabrication of suitable nano-multiferroic samples. Addressing these issues is an important prerequisite for the implementation of multiferroics in future nanoscale devices and sensors. In this paper we report on the local measurement of the magnetoelectric coefficient in bilayered ceramic nanocomposites from the variation in the longitudinal piezoelectric coefficient of the electrostrictive layer in the presence of a magnetic field. The experimental data were analyzed using a theoretical relationship linking the piezoelectric coefficient to the magneto-electric coupling coefficient. Our results confirm the presence of a measurable magnetoelectric coupling in bilayered nanocomposites constructed by a perovskite as the electrostrictive phase and two different ferrites (cubic spinel and hexagonal) as the magnetic phases. The reported experimental values as well as our theoretical approach are both in good agreement with previously published data for bulk and nanostructure magnetoelectric multiferroics.

Fundamentals of Multiferroic Materials and Their Possible Applications

“…In most cases however, common requirements that must be strictly observed for applications are: (a) multiferroic materials must display large magneto-electric coupling effects, preferably at room temperature; (b) multiferroic materials and devices must be easy to manufacture and preferably consisting of cheap chemical elements and compounds; (c) multiferroic structures must be suitable for large scale production and integration at chip / wafer level; (d) multiferroic structures must be suitable for fabrication at micro-and nano-scale sizes, without loss of functionality. In fact, there is already experimental evidence that multiferroic magneto-electric coupling is 24 M. M. VOPSON preserved even at nano-scale, 164 suggesting that nano-technologies based on these materials are indeed possible.…”

1D core–shell magnetoelectric nanocomposites by template-assisted liquid phase deposition

“…A similar behavior also was observed in bilayered perovskite-spinel ferrite nanocomposites in which the mag-netic layers possessed both negative and positive magneto-striction coefficients and the variation of the piezoelectric coefficients is positive and negative, respectively. 37 We stress out here that positive/negative variation of the piezoelectric coefficient of the multiferroic nanocomposite in the presence of the magnetic field is dictated by negative/positive sign of the magnetostriction coefficient.…”

“…This systematic variation in the piezoelectric coefficient of the sample originates from a strain-mediated ME coupling between the two ferroic phases of the nano composite material. 37…”

Magnetoelectric coupling in nanoscale 0–1 connectivity

“…A classical butterfly shape of the displacement and 180˚ change in the phase confirms a fully reversible PE dynamic, which is explained by the bias-induced di-polarization process of a PE material. [32][33][34] The amplitude displacement at positive biases regime (10~25V) is less than that at negative biases regime (-10~-25V), resulting in larger left wing of the butterfly loops in comparison to the right wing. This unique PE dynamic was also observed in our earlier work on regenerated cellulose, indicating cellulose's amplitude displacement is more sensitive to negative biases stimulation.…”