title: Joining Chemical Pressure and Epitaxial Strain to Yield Y-doped BiFeO3 Thin Films with High Dielectric Response.
abstract: BiFeO3 is one of the most promising multiferroic materials but undergoes two major drawbacks: low dielectric susceptibility and high dielectric loss. Here we report high in-plane dielectric permittivity (ε' ∼2500) and low dielectric loss (tan δ < 0.01) obtained on Bi0.95Y0.05FeO3 films epitaxially grown on SrTiO3 (001) by pulsed laser deposition. High resolution transmission electron microscopy and geometric phase analysis evidenced nanostripe domains with alternating compressive/tensile strain and slight lattice rotations. Nanoscale mixed phase/domain ensembles are commonly found in different complex materials with giant dielectric/electromechanical (ferroelectric/ relaxors) or magnetoresistance (manganites) response. Our work brings insight into the joined role of chemical pressure and epitaxial strain on the appearance of nanoscale stripe structure which creates conditions for easy reorientation and high dielectric response, and could be of more general relevance for the field of materials science where engineered materials with huge response to external stimuli are a highly priced target.
authors.affiliation: National Institute for Laser, Plasma and Radiation Physics, 077125 Magurele, Romania.
authors.forename: N D
authors.initials: ND
authors.lastname: Scarisoreanu
authors.affiliation: CNR-ISC, Istituto dei Sistemi Complessi, Area della Ricerca di Roma-Tor Vergata, Via del Fosso del Cavaliere 100, I-00133 Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Craciun
authors.affiliation: National Institute for Laser, Plasma and Radiation Physics, 077125 Magurele, Romania.
authors.forename: R
authors.initials: R
authors.lastname: Birjega
authors.affiliation: National Institute for Laser, Plasma and Radiation Physics, 077125 Magurele, Romania.|Faculty of Physics, University of Bucharest, 077125 Magurele, Romania.
authors.forename: V
authors.initials: V
authors.lastname: Ion
authors.affiliation: National Institute of Material Physics, 077125, Magurele, Romania.
authors.forename: V S
authors.initials: VS
authors.lastname: Teodorescu
authors.affiliation: National Institute of Material Physics, 077125, Magurele, Romania.
authors.forename: C
authors.initials: C
authors.lastname: Ghica
authors.affiliation: National Institute of Material Physics, 077125, Magurele, Romania.
authors.forename: R
authors.initials: R
authors.lastname: Negrea
authors.affiliation: National Institute for Laser, Plasma and Radiation Physics, 077125 Magurele, Romania.
authors.forename: M
authors.initials: M
authors.lastname: Dinescu