Elastic responses to different electric-field directions in relaxor ferroelectric Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 single crystals

Abstract

Micro-Brillouin scattering was applied to relaxor-based complex perovskite Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 (PZN–9% PT) single crystals during a polarization switching under two different electric-field directions along 〈111〉 and 〈101〉. Brillouin spectra consisted of one longitudinal and two transverse acoustic modes, and the Brillouin shift and the full width at half maximum of these modes showed clear changes near the coercive field (Ec) where the polarization reversal occurred. In particular, the lowest transverse mode was the most sensitive to Ec. In the case of 〈111〉-poled crystals the Brillouin spectrum exhibited an asymmetric shape in a narrow electric-field range near Ec due to a coupling between the lowest transverse mode and a central peak. In the case of 〈101〉-poled crystals, the lowest transverse mode showed an abrupt softening at Ec and a slow recovery to the initial value upon further increasing the electric field. This may indicate the appearance of the monoclinic symmetry where the polarization can rotate freely toward the orthorhombic phase in the MB plane under the electric field along the 〈101〉 direction. The observation of no changes in the Brillouin spectra with decreasing the electric field seems to indicate that the PZN–9% PT crystal, poled under the field along 〈101〉, does not become rhombohedral, but remains in the induced orthorhombic phase upon the removal of the field.

Field-induced successive phase transitions of Pb(Zn1/3Nb2/3)O3-x%PbTiO3 crystals

“…They showed that a successive C → T → Mc transitions occurred on the field-cooling process and unknown phase X, which is a different new phase, appeared on the zero-field cooling [11]. Brillouin scattering has been performed on PZN, PZN-4.5%PT and PZN-9%PT with near the MPB composition [12,13].…”

Microstructures and electrical properties of lead zinc niobate–lead titanate–lead zirconate ceramics using microwave sintering

“…[1][2][3] The PZN has not only very good dielectric properties but also excellent piezoelectric properties. [4][5][6][7][8][9][10][11] However, synthesizing perovskite PZN or Pb(Zn 1/3 Nb 2/3 )O 3 -PbTiO 3 (PZN-PT) ceramics near morphotropic phase boundary (MPB) using a conventional ceramic process is difficult, because pyrochlore phases form easily. [12][13][14][15] Perovskite PZN and 0.9PZN-0.1PT crystals have been reported to be thermodynamically unstable over the wide range of temperatures 600-1400 • C. 13 Lim et al 14 investigated that the perovskite PZN-PT single crystals decomposed to the pyrochlore phase, PbO and ZnO during high temperature annealing, even in PbO-rich environments.…”

Micro-Brillouin scattering study of ferroelectric relaxor Pb[(Zn1∕3Nb2∕3)0.91Ti0.09]O3 single crystals under the electric field along the [001] direction

“…10 Detailed phase diagrams of PZN-x % PT and PMN-x % PT single crystals near MPB have been studied resently based on synchrotron x-ray measurements. [17][18][19] Since there has been no systematic investigation into the FC effects on PZN-9%PT single crystals, we examined the elastic properties of this composition in a large temperature range. These two phase transitions are known to be first-order phase transitions with noticeable thermal hysteresis.…”