Structure and lattice dynamics of heterostructures based on bismuth ferrite and barium strontium titanate on magnesium oxide substrates

Phonon and magnon excitations in Raman spectra of an epitaxial bismuth ferrite film

“…The BFO film studied in this work, apparently, has a monoclinic structure with the space group Cc and four formula units per unit cell, which has been repeatedly suggested in a number of studies dealing with BFO films [16,23,26]. In this case, we should expect the appearance of 14A' + 13A'' optical phonons Frequencies (in cm -1 ) of lines in the Raman spectra of the BFO film according to the data obtained in this work and the data available in the literature [25] …”

“…The latter assumption is confirmed by the difference in the shapes of the spectra measured in the scattering geom etries Y(XZ) and Z(YX) , which should be identical in the case of rhombohedral symmetry [23]. Upon deposition of the BFO film on the (001) face of the cubic crystal (in our case, the MgO layer was prelimi narily coated with SRO/STO perovskite layers, which provided the epitaxial growth of the BFO film), the structure can be distorted to tetragonal or monoclinic symmetry [16,26] with a change in the scheme of rotations of the oxygen octahedra. For the tetragonal symmetry P4mm with one formula unit in the unit cell, we can expect that the Raman spectra will contain the 4A 1 + B 1 + 5E modes.…”

“…In recent years, epitaxial BFO films have been synthesized on various substrates and buffer layers. It has been found that, apart from the rhombohedral phase [6][7][8][9], in epitaxial BFO films, there are different structural distortions not observed in the bulk material, such as tetragonal [5,10,11], orthorhombic [12][13][14], and monoclinic [15][16][17][18] [19] that the antiferromagnetic phase transi tion temperature T N depends weakly on the strain of the film, whereas the ferroelectric phase transition temperature T C significantly decreases with an increase in the strain of the film, which was explained in [19] by the interaction of polar and rotational dis tortions in the BFO lattice. This paper presents the results of the Raman scat tering investigation of a BFO epitaxial film in the tem perature range from 295 to 1100 K. We have performed a comparison of the observed first order Raman spec tra of the film with the spectra of single crystal BFO samples.…”

Nonlinear optical microscopy and spectroscopy of ferroelectric and multiferroic materials

“…The multilayer nanostructures were fabricated by high frequency sputtering on the MgO substrate [6].…”

Processing‐Property Relationships in Electrospun Janus‐Type Biphasic Ceramic Nanofibers

“…Although multiferroic composites can be synthesized from a variety of materials, most consist of ceramic oxides. Bulk materials can be readily synthesized by sintering together commercially available powders of piezoelectric [e.g., lead zirconate titanate (PZT), BaTiO 3 ] and magnetostrictive (e.g., Ni x Zn 1− x Fe 2 O 4 , CoFe 2 O 4 ) materials . Although readily prepared, these bulk or particulate‐based materials exhibit magnetoelectric coupling that is well below theoretical predictions .…”