Giant magnetoelectric coupling interaction in BaTiO{sub 3}/BiFeO{sub 3}/BaTiO{sub 3} trilayer multiferroic heterostructures

Journal Article · Mon Aug 24 00:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4929729· OSTI ID:22489170

Gupta, Rekha ^[1]; Chaudhary, Sujeet ^[2]

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1. CSIR-National Physical Laboratory, New Delhi 110012 (India)
2. Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India)

Multiferroic trilayer thin films of BaTiO{sub 3}/BiFeO{sub 3}/BaTiO{sub 3} were prepared by RF-magnetron sputtering technique at different thicknesses of BiFeO{sub 3} layer. A pure phase polycrystalline growth of thin films was confirmed from X-ray diffraction results. The film showed maximum remnant electric polarization (2P{sub r}) of 13.5 μC/cm{sup 2} and saturation magnetization (M{sub s}) of 61 emu/cc at room temperature. Thermally activated charge transport dominated via oxygen vacancies as calculated by their activation energy, which was consistent with current–voltage characteristics. Magnetic field induced large change in resistance and capacitance of grain, and grain boundary was modeled by combined impedance and modulus spectroscopy in the presence of varied magnetic fields. Presence of large intrinsic magnetoelectric coupling was established by a maximum 20% increase in grain capacitance (C{sub g}) with applied magnetic field (2 kG) on trilayer having 20 nm BiFeO{sub 3} layer. Substantially higher magnetoelectric coupling in thinner films has been observed due to bonding between Fe and Ti atoms at interface via oxygen atoms. Room temperature magnetoelectric coupling was confirmed by dynamic magnetoelectric coupling, and maximum longitudinal magnetoelectric coupling of 515 mV/cm-Oe was observed at 20 nm thickness of BiFeO{sub 3}. The observed magnetoelectric properties are potentially useful for novel room temperature magnetoelectric and spintronic device applications for obtaining higher voltage at lower applied magnetic field.

• OSTI ID: 22489170
• Journal Information: Applied Physics Letters, Vol. 107, Issue 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATOMS
CAPACITANCE
CHARGE TRANSPORT
COUPLING
ELECTRIC POTENTIAL
GRAIN BOUNDARIES
MAGNETIC FIELDS
MAGNETIC PROPERTIES
MAGNETIZATION
MAGNETRONS
OXYGEN
POLARIZATION
POLYCRYSTALS
SPECTROSCOPY
SPUTTERING
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
TITANATES
X-RAY DIFFRACTION