Tailoring ergodicity through selective A-site doping in the Bi1/2Na1/2TiO3–Bi1/2K1/2TiO3 system

Abstract

Articles you may be interested inSolid-state conversion of (Na1/2Bi1/2)TiO3-BaTiO3-(K1/2Na1/2)NbO3 single crystals and their piezoelectric properties Appl. Phys. Lett. 104, 222910 (2014) The morphotropic phase boundary composition Bi 1/2 Na 1/2 TiO 3 -20 mol. % Bi 1/2 K 1/2 TiO 3 was chosen as initial material to do selective A-site aliovalent doping replacing Na and K by 1 at. % La, respectively. The materials were studied macroscopically by measuring dielectric and electromechanical properties. The Na-replaced material has a lower freezing temperature T fr , lower remanent polarization and remanent strain, and thus a higher degree of ergodicity than the K-replaced material. These results are contrasted with local poling experiments and hysteresis loops obtained from piezoresponse force microscopy. The faster relaxation of the tip-induced local polarization and the lower remanent state in bias-on and -off loops confirm the higher degree of ergodicity of the Na-replaced material. The difference in functional properties is attributed to small variations in chemical pressure achieved through selective doping. Raman results support this working hypothesis. V C 2015 AIP Publishing LLC.[http://dx

Yttrium Iron Garnet/Barium Titanate Multiferroic Composites

“…Nevertheless, the A 1 (TO) (~250 cm −1 ) for BT shifts toward lower frequencies, which may be indicative of residual strain. This is due to the local scale of the Raman probe, compared to the average picture given by XRD . Nevertheless, it is worth to mention that the XRD reflections for 30 wt% composite are asymmetric, which is also consistent with residual strain.…”

“…Moreover, no additional modes due to parasitic phases are observed. Nevertheless, the A 1 (TO) (~250 cm −1 ) for BT shifts toward lower frequencies, which may be indicative of residual strain …”

Revealing the core-shell interactions of a giant strain relaxor ferroelectric 0.75Bi1/2Na1/2TiO3-0.25SrTiO3

“…Complete processing details of this material can be found elsewhere32. The sample preparation processing for PFM measurements followed a protocol reported elsewhere27.…”

“…After removing the field, the core remains poled, whereas the shell reversibly relaxes to the initial state2734. We thus propose a model for the polarisation evolution of the core-shell region in the poling experiment (Fig.…”

“…Both the in-plane and out-of-plane polarisation can be mapped on the sample surface2527. The domain distribution and evolution strongly depend on the variability of the polarisation beneath the surface.…”