Elastic anomalies are signatures of phase transitions in condensed matters and have traditionally been studied using various techniques spanning from neutron scattering to static mechanical testing. Here, using band-excitation elastic/piezoresponse spectroscopy, we probed sub-MHz elastic dynamics of a tip bias-induced rhombohedral-tetragonal phase transition of strained (001)-BiFeO3 (rhombohedr...

Solid-state sintering method was used to prepare ceramic materials based on bismuth ferrite, i.e., (BiFeO3)1 - x -(BaTiO3) x and Bi1 - x Nd x FeO3 solid solutions and the Aurivillius Bi5Ti3FeO15 compound. The structure of the materials was examined using X-ray diffraction, and the Rietveld method was applied to phase analysis and structure refinement. Magnetoelectric coupling was registered in ...

The connection between noncentrosymmetric materials’ structure, electronic structure, and bulk photovoltaic performance remains not well understood. In particular, it is still unclear which photovoltaic (PV) mechanisms are relevant for the recently demonstrated visible-light ferroelectric photovoltaic (K,Ba)(Ni,Nb)O3−δ . In this paper, we study the bulk photovoltaic effect (BPVE) of (K,Ba)(Ni,N...

Experiments demonstrate that under large epitaxial strain a coexisting striped phase emerges in BiFeO3 thin films, which comprises a tetragonal-like (T') and an intermediate S' polymorph. It exhibits a relatively large piezoelectric response when switching between the coexisting phase and a uniform T' phase. This strain-induced phase transformation is investigated through a synergistic combinat...

Elastic and anelastic properties of a member of the BiFeO3-CaFeO2.5 perovskite solid solution (BCFO), which is known to have multiple instabilities, have been investigated by resonant ultrasound spectroscopy. This phase, with 64% Bi and 36% Ca on the A site, is antiferromagnetic (TN ∼650 K) and has an ordered arrangement of oxygen vacancies with tetragonal lattice geometry. The inverse mechanic...

The surface of BiFeO3 single crystals has been characterized at the local level using several AFM-based techniques. We have observed the presence of two different epilayers showing electrical and mechanical properties different from those of the bulk: a ferroelectrically “dead” outer skin of 5 nm sitting upon a subsurface layer that displays an extremely fine pattern of hierarchical self-ordere...

The thin-film heterostructures or nanocomposites exhibit vastly different properties from those observed in bulk systems. Herein, a nanocomposite of reduced graphene oxide (RGO) and BiFeO3 (BFO), the remnant ferroelectric polarization is found to follow nonmonotonic magnetic field dependence at room temperature as applied swept across 0–20 kOe on pristine sample. Bulk BiFeO3, contrast, exhibits...