Ferroelectric-ferromagnetic multilayers: A magnetoelectric heterostructure with high output charge signal

Journal Article · Sun Sep 21 04:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4896189· OSTI ID:22306009

Prokhorenko, S. ^[1]; Kohlstedt, H. ^[2]

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1. Laboratoire Structures, Propriétés et Modélisation des Solides, UMR CNRS—École Centrale Paris, 92295 Châtenay-Malabry (France)
2. Nanoelektronik, Technische Fakultät, Christian-Albrechts-Universität zu Kiel, D-24143 Kiel (Germany)

Multiferroic composites and heterostructures comprising ferroelectric and ferromagnetic materials exhibit room-temperature magnetoelectric (ME) effects greatly exceeding those of single-phase magnetoelectrics known to date. Since these effects are mediated by the interfacial coupling between ferroic constituents, the ME responses may be enhanced by increasing the density of interfaces and improving their quality. A promising material system providing these features is a ferroelectric-ferromagnetic multilayer with epitaxial interfaces. In this paper, we describe theoretically the strain-mediated direct ME effect exhibited by free-standing multilayers composed of single-crystalline ferroelectric nanolayers interleaved by conducting ferromagnetic slabs. Using a nonlinear thermodynamic approach allowing for specific mechanical boundary conditions of the problem, we first calculate the polarization states and dielectric properties of ferroelectric nanolayers in dependence on the lattice mismatch between ferroic constituents and their volume fractions. In these calculations, the ferromagnetic component is described by a model which combines linear elastic behavior with magnetic-field-dependent lattice parameters. Then the quasistatic ME polarization and voltage coefficients are evaluated using the theoretical strain sensitivity of ferroelectric polarization and measured effective piezomagnetic coefficients of ferromagnets. For Pb(Zr₀.₅Ti₀.₅)O₃-FeGaB and BaTiO₃-FeGaB multilayers, the ME coefficients are calculated numerically as a function of the FeGaB volume fraction and used to evaluate the output charge and voltage signals. It is shown that the multilayer geometry of a ferroelectric-ferromagnetic nanocomposite opens the way for a drastic enhancement of the output charge signal. This feature makes biferroic multilayers advantageous for the development of ultrasensitive magnetic-field sensors for technical and biomedical applications.

• OSTI ID: 22306009
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 11 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BORON COMPLEXES
BOUNDARY CONDITIONS
CRYSTAL DEFECTS
DIELECTRIC PROPERTIES
ELECTRICAL PROPERTIES
FERROELECTRIC MATERIALS
FERROMAGNETIC MATERIALS
GALLIUM COMPOUNDS
IRON COMPOUNDS
LATTICE PARAMETERS
LAYERS
LEAD COMPOUNDS
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MONOCRYSTALS
OXYGEN COMPOUNDS
POLARIZATION
TITANATES
ZIRCONATES