Full text loading...
Structure and microstructure of 0.25 mol. % Cu-doped KNN 50/50 ceramics. (a) XRD pattern. The inset shows the region where secondary phases would be expected with enhanced magnification. Peaks are indexed according to JCPDS 71-2171. (b) SEM micrograph of the polished and chemically etched surface.
Binding energies of the defect complexes and vs. Fermi energy calculated with DFT. VBM and CBM denote the valence band maximum and conduction band minimum, respectively.
Q-band (34.1 GHz) EPR-spectrum of a 0.25 mol. % copper-doped KNN 50/50 ceramic, recorded at a temperature of 20 K. The two different quartet hyperfine structures for two different types of Cu2+ centers are indicated. The two observed centers indicate the formation of mutually compensating and defect complexes.
and defect complexes, showing only the B-sites (solid circles) and the oxygen (open circles) ions, as well as oxygen vacancies (red squares). (a) Electric dipole with indicated orientations for spontaneous (PS ) and defect polarization (PD ). (b) Elastic dipole with anticipated lattice deformation.
Interaction between the defect complex with two types of domain walls. The orientation of spontaneous polarization is represented by a bold blue arrow. (a) Ferroelectric and defect-induced strain parallel on one side of the domain wall and perpendicular on the other. (b) Ferroelectric and defect-induced strain parallel on both sides of the domain wall.
Article metrics loading...