Direct measurement of the remanent polarization of high quality (001)-oriented epitaxial BiFeO3 thin films shows a strong strain dependence, even larger than conventional (001)-oriented PbTiO3 films. Thermodynamic analysis reveals that a strain-induced polarization rotation mechanism is responsible for the large change in the out-of-plane polarization of (001) BiFeO3 with biaxial strain while the spontaneous polarization itself remains almost constant.

We have studied the stability of domains and domain walls in multiferroic BiFeO3 thin films using a combination of piezoelectric force microscopy and phase-field simulations. We have discovered that a film-substrate misfit strain may result in a drastically different thermodynamic stability of two parallel domain walls with the same orientation. A fundamental understanding of the underlying physics, the stress distribution in a domain structure, leads to a novel approach to control the ferroelastic domain stability in the multiferroic BiFeO3 system.

Effect of Pt bottom electrode texture selection on the tetragonality and physical properties of Ba0.8Sr0.2TiO3 thin films produced by pulsed laser deposition J. Appl. Phys. 112, 044105 (2012) Relationship between dielectric coefficient and Urbach tail width of hydrogenated amorphous germanium carbon alloy films Appl. Phys. Lett. 101, 042109 (2012) Interfacial oxide re-growth in thin film metal oxide III-V semiconductor systems A single-domain thermodynamic theory is employed to predict the spontaneous polarizations of ͑001͒ c , ͑101͒ c , and ͑111͒ c oriented epitaxial BiFeO 3 thin films grown on dissimilar substrates. The effects of various substrate-induced strains on the spontaneous polarization were studied. The dependences of the spontaneous polarization on film orientations and the types of substrate-induced strains were analyzed.

Articles you may be interested inElectric-field-controlled interface strain coupling and non-volatile resistance switching of La1-xBaxMnO3 thin films epitaxially grown on relaxor-based ferroelectric single crystals Adjustable magnetoelectric effect of self-assembled vertical multiferroic nanocomposite films by the in-plane misfit strain and ferromagnetic volume fraction Electric-field-induced magnetization reversal in 1-3 type multiferroic nanocomposite thin films A phase-field model was developed for studying the magnetoelectric coupling effect in epitaxial ferroelectric and magnetic nanocomposite thin films. The model can simultaneously take into account the ferroelectric and magnetic domain structures, the electrostrictive and magnetostrictive effects, substrate constraint, as well as the long-range interactions such as magnetic, electric, and elastic interactions. As an example, the magnetic-field-induced electric polarization in BaTiO 3 -CoFe 2 O 4 nanocomposite film was analyzed. The effects of the film thickness, morphology of the nanocomposite, and substrate constraint on the degree of magnetoelectric coupling were discussed.

No abstract