Quantitative phase separation in multiferroic Bi0.88Sm0.12FeO3 ceramics via piezoresponse force microscopy

Abstract

BiFeO 3 (BFO) is a classical multiferroic material with both ferroelectric and magnetic ordering at room temperature. Doping of this material with rare-earth oxides was found to be an efficient way to enhance the otherwise low piezoelectric response of unmodified BFO ceramics. In this work, we studied two types of bulk Sm-modified BFO ceramics with compositions close to the morphotropic phase boundary (MPB) prepared by different solid-state processing methods. In both samples, coexistence of polar R3c and antipolar P bam phases was detected by conventional X-ray diffraction (XRD); the non-polar P nma or P bnm phase also has potential to be present due to the compositional proximity to the polar-to-non-polar phase boundary. Two approaches to separate the phases based on the piezoresponse force microscopy measurements have been proposed. The obtained fractions of the polar and non-polar/anti-polar phases were close to those determined by quantitative XRD analysis. The results thus reveal a useful method for quantitative determination of the phase composition in multi-phase ceramic systems, including the technologically most important MPB systems.

Temperature dependent piezoelectric response and strain–electric-field hysteresis of rare-earth modified bismuth ferrite ceramics

“…These regions with visible domains were previously identified as the R3c phase, and the regions exhibiting no PFM contrast (i.e. no visible domains) were identified as the Pbam phase 33,41 . While PFM with its detection limitation (>40 nm) was unable to identify a domain structure in the Pbam phase, previous reports demonstrate that nanosized regions with greyscale contrast are visible with TEM, but are unidentified 33 .…”

Impact of texturing on the phase transitions in sol–gel‐processed Bi(Sm)FeO3 thin films on LaNiO3‐buffered silicon

“…PFM is a suitable method to evaluate local piezoelectric responses, 19,20 and provides quantitative information on the occurrence/distribution of the ferroelectric phase in materials. PFM imaging has been proved to be an effective and reliable method to quantify the phase compositions in rare‐earth‐doped BiFeO 3 , comparable to XRD characterization, as well in other ferroelectrics like Bi 1/2 Na 1/2 TiO 3 ‐BaTiO 3 38,39 . PFM scanning of the nontextured and textured Bi(Sm)FeO 3 films was conducted.…”

Micro‐to‐nano domain structure and orbital hybridization in rare‐earth‐doped BiFeO3 across morphotropic phase boundary

“…A PbZrO 3 ‐type Pnam structure (with doubling unit cell along the c ‐direction) was reported in (Bi 1− x Sm x )FeO 3 ( x = 0.1 and 0.15) ceramics . A coexistence of R 3 c and antipolar PbZrO 3 ‐like orthorhombic Pbam or Pnma symmetries was suggested at x = 0.1‐0.155 . An orthorhombic Pnma symmetry was proposed at x = 0.18 .…”

“…21 A coexistence of R3c and antipolar PbZrO 3 -like orthorhombic Pbam or Pnma symmetries was suggested at x = 0.1-0.155. 4,[22][23][24][25] An orthorhombic Pnma symmetry was proposed at x = 0.18. 23 A polar-to-nonpolar phase transition was suggested at x~0.2, below which a rhombohedral and two orthorhombic modifications were observed.…”