Dielectric Measurements on SBN:Ce

Low-temperature transverse dielectric and pyroelectric anomalies of uniaxial tungsten bronze crystals

“…10,14 Consistent with previous results, we also observed transverse dielectric anomalies and field-induced pyroelectric responses along the directions perpendicular to the polar c axis in all examined TB crystals. Considering our results and the previous reports 9-13 these low-temperature anomalies seem to be universal in the tetragonal TB family.…”

“…From the x-ray powder diffraction and the remanent polarization measurement along several crystallographic axes, they concluded that the examined TB crystals experienced structural phase transitions from tetragonal to monoclinic symmetry due to polarization tilting away from the c axis toward the ͓110͔ direction in the tetragonal structure. 9 Thereafter, similar observations on the low-temperature anomalies of several TB compounds have been reported by dielectric measurements [10][11][12][13] and Raman spectroscopy. 14 These low-temperature anomalies appeared to have no relation to the high-temperature tetragonal-to-tetragonal and tetragonal-to-orthorhombic transitions in the case of ͑Sr 2Ϫx Ca x ) 2 Na 2 Nb 10 O 30 .…”

Charge‐Compensating Defect in Ceria‐Doped Strontium Barium Niobate by Electron Energy‐Loss Spectroscopy and X‐ray Photoelectron Spectroscopy

“…For CeO 2 -doped SBN, the valence state of the cerium ion has been determined as 3ϩ based on electron paramagnetic resonance (EPR) spectra. 9,11 Although Niemann et al 16 have suggested that the cerium ion occurs mainly in the 3ϩ valence state, they have not completely excluded the presence of Ce 4ϩ because they used a low concentration of cerium ion that led to the low signal to noise ratio in the XPS spectrum. Therefore, in the current investigation, we also have used XPS but with a high concentration of cerium ion to confirm that Ce 4ϩ indeed does not exist, as shown in Fig.…”