title: Heterogeneous grain-scale response in ferroic polycrystals under electric field.
abstract: Understanding coupling of ferroic properties over grain boundaries and within clusters of grains in polycrystalline materials is hindered due to a lack of direct experimental methods to probe the behaviour of individual grains in the bulk of a material. Here, a variant of three-dimensional X-ray diffraction (3D-XRD) is used to resolve the non-180° ferroelectric domain switching strain components of 191 grains from the bulk of a polycrystalline electro-ceramic that has undergone an electric-field-induced phase transformation. It is found that while the orientation of a given grain relative to the field direction has a significant influence on the phase and resultant domain texture, there are large deviations from the average behaviour at the grain scale. It is suggested that these deviations arise from local strain and electric field neighbourhoods being highly heterogeneous within the bulk polycrystal. Additionally, the minimisation of electrostatic potentials at the grain boundaries due to interacting ferroelectric domains must also be considered. It is found that the local grain-scale deviations average out over approximately 10-20 grains. These results provide unique insight into the grain-scale interactions of ferroic materials and will be of value for future efforts to comprehensively model these and related materials at that length-scale.
authors.affiliation: School of Materials Science and Engineering, UNSW Australia, Sydney NSW 2052, Australia.
authors.forename: John E
authors.initials: JE
authors.lastname: Daniels
authors.affiliation: NEXMAP, DTU Physics, 2800 Kgs. Lyngby, Denmark.
authors.forename: Marta
authors.initials: M
authors.lastname: Majkut
authors.affiliation: School of Materials Science and Engineering, UNSW Australia, Sydney NSW 2052, Australia.
authors.forename: Qingua
authors.initials: Q
authors.lastname: Cao
authors.affiliation: NEXMAP, DTU Physics, 2800 Kgs. Lyngby, Denmark.
authors.forename: Søren
authors.initials: S
authors.lastname: Schmidt
authors.affiliation: European Synchrotron Radiation Facility, Grenoble 38000, France.
authors.forename: Jon
authors.initials: J
authors.lastname: Wright
authors.affiliation: School of Mechanical and Advanced Materials Engineering, UNIST, Ulsan, Republic of Korea.
authors.forename: Wook
authors.initials: W
authors.lastname: Jo
authors.affiliation: NEXMAP, DTU Physics, 2800 Kgs. Lyngby, Denmark.
authors.forename: Jette
authors.initials: J
authors.lastname: Oddershede