Raman study of an electric-field-induced phase transition inPb(Zn1/3Nb2/3

Abstract

Electric-field-induced structural transition of a single crystal Pb(Zn 1/3 Nb 2/3 )O 3 -8%PbTiO 3 grown in the ͑001͒ direction was studied by use of Raman scattering spectroscopy. By comparing the changes in Raman spectra induced by the electric field with the temperature-dependent changes, we could confirm that the structural transition to tetragonal phase is initiated at a threshold electric field E c1 and completed at higher transition field E c2 . In the electric-field range from E c1 to E c2 , it is found that rhombohedral and tetragonal phases coexist. The lower threshold field E c1 is found to coincide with the field at which the strain rises abruptly in the strain electric-field hysteresis loop while the upper threshold field E c2 corresponds to the electric field where a slope change is observed in the high-field saturation region beyond the hysteresis loop.

Probing the Nanodomain Origin and Phase Transition Mechanisms in (Un)Poled PMN-PT Single Crystals and Textured Ceramics

“…The Raman spectra of both poled and unpoled PMN-29%PT single crystal and PMN-34.5%PT highly textured ceramic look at a first view very similar to those usually observed for relaxor ferroelectric samples [54,60,61,62,63,70,73,74,94,95,96]. They consist of a number of broad bands observed over the whole measured temperature range.…”

“…Among the most studied perovskite solid solutions , one can easily place the different relaxor ferroelectric solid solutions [45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74] such as PbZr 1−x Ti x O 3 (PZT) [48,53,54], (Pb,La)Zr 1−x Ti x O 3 (PLZT) [55,56], (1−x)Pb(Mg 1/3 Nb 2/3 )O 3 –xPbTiO 3 (PMN-PT) [57,58,59,60,61,62,63,64,65,66,67] and (1−x)Pb(Zn 1/3 Nb 2/3 )O 3 −xPbTiO 3 (PZN-PT) [67,68,69,70,71,72,73,74]. Note that we will use solid solutions formula in this article as is general in the literature; however, one should use this with caution, since as we will show, the studied materials are not really solid solutions at the scale determining most of their properties!…”

“…Despite intensive studies, the physical and electrochemical properties directly connected with the relaxor ferroelectric solid solutions are still not fully understood. Since the physics of these systems takes place mainly on the nanoscale, the Raman spectroscopy that probes the local structure at the very short range is one of the most useful techniques to study these compounds [14,15,16,17,54,60,61,62,63,70,73,74]. Moreover, this technique studies directly the chemical bond anharmonicity, which allows—especially if coupled with the thermal expansion measurements as we will show below—detection of any very subtle structural modifications that are overlooked by many studies.…”

Study of field-induced phase transitions in 0.68PbMg1/3Nb2/3O3–0.32PbTiO3 relaxor single crystal by polarized micro-Raman spectroscopy

“…[8][9][10][11][12][13][14][15][16] The anomalies of Raman active-mode are strongly associated with phase transitions. Moreover, the light couples directly with the ferroelectric polarization make it useful in study of lattice dynamics.…”

“…This effect is probably ascribed to the existence of micropolar domains, which partly influences the vibrational properties, as well as the Raman selection rules. 8,18 To better ascertain the locations and the number of Raman modes, the Raman spectra are decomposed into Lorentzian-shaped peaks. The deconvoluted spectrum is displayed in the VV geometry and ten modes are discernible in the frequency range of 100-1000 cm À1 .…”