Micro-Raman Study of Self-Assembled Nanostructures: (1−x)PZN:xPT Solid Solution

1999 ◽  
Vol 581 ◽  
Author(s):  
S. Gupta ◽  
R. S. Katiyar ◽  
R. Guo ◽  
A. S. Bhalla
Keyword(s):  
Lead Titanate ◽  
Relaxor Ferroelectrics ◽  
Structure Property ◽  
Temperature Dependent ◽  
Property Relations ◽  
Polarization Mechanism ◽  
Raman Study ◽  
Self Assembled ◽  
Polarized Raman ◽  
Temperature Dependent Study

ABSTRACTRelaxor ferroelectrics are one of the important classes of self-assembled nanostructure composite materials. Interesting features associated with the nanoregions give rise to the most interesting device related characteristics and unusual properties in these materials. Besides, they possess the largest property coefficients by themselves or when modified with lead titanate (PT). In this report, a detailed temperature dependent study has been carried out on (1-x)PZN-xPT relaxors with compositions x = 0.05 and 0.085 using polarized Raman scattering under optical and E-field variables and inferred the structure-property relations in order to obtain information to characterize the material for matching the application criteria. In addition, phase transitions associated with the relaxors have also been investigated to understand the polarization mechanism(s) for the unpoled and poled specimens.

Polarized Raman study of self-assembled Ge/Si dots under hydrostatic pressure

2009 ◽  
Vol 246 (3) ◽  
pp. 482-485 ◽  
Author(s):  
J. S. Reparaz ◽  
A. Bernardi ◽  
A. R. Goñi ◽  
M. I. Alonso ◽  
M. Garriga
Keyword(s):  
Hydrostatic Pressure ◽  
Raman Study ◽  
Self Assembled ◽  
Polarized Raman

Nanodomain Size Distribution in Relaxor Ferroelectrics Determined from Temperature Dependent Raman Scattering

2006 ◽  
Vol 966 ◽  
Author(s):  
Sanju Gupta
Keyword(s):  
Phase Transition ◽  
Solid Solution ◽  
Raman Spectroscopy ◽  
Raman Scattering ◽  
Size Distribution ◽  
Raman Spectra ◽  
Structural Phase ◽  
Relaxor Ferroelectrics ◽  
Temperature Dependent ◽  
Polarization Mechanism

ABSTRACTRelaxors (PZN, in particular) is an important class of self-assembled nanostructure composite ferroelectric oxides (or perovskite) materials. The interesting features associated with the nanoregions/nanodomains required to describe these relaxors give rise to the most relevant device related characteristics and peculiar physical properties in these materials. In addition, they possess astronomical property coefficients by themselves or when modified with lead titanate (PT) forming solid solution. In the past, we conducted temperature dependent Raman scattering studies on solid solution (1−x)PZN−xPT relaxors single crystals with varying composition; x = 0.02, 0.085, and 0.11. These studies were performed to obtain relevant information about lattice/phonon dynamics for matching the application criteria such as electromechanical actuators. We showed that the sharp structural phase transition occurs at or near 460 K which is a first-order transition by fitting two spectroscopic variables in Raman spectra for one of the representative bands occurring at 277 cm−1. Besides structural phase transition, polarization mechanism for the unpoled (x = 0.02) and poled (x = 0.05) specimens is also investigated to understand the polarization mechanism in relaxors using Raman spectroscopy. The difference in the case of poled specimen is accounted for by the influence of residual electric field. Poling also suggested an enhanced local ordering and the increase in the volume of the polar nano-regions. In the present report, we attempted to determine the nanopolar region size and distribution using the above mentioned temperature dependent Raman spectra. We discuss the most suitable mathematical form of nanodomain size distribution for such inhomogeneous material is log-normal and it is bimodal depending upon the temperature regime in addition to composition. These studies helped to determine the size distribution of nanoscopic embodiments in relaxor ferroelectrics using Raman spectroscopy as a function of temperature which is a dynamical phenomenon.

Dynamics of the commensurate-incommensurate phase transition in C2O4D ND4, 1/2 D2O: a polarized Raman study under pressure

1993 ◽  
Vol 3 (4) ◽  
pp. 1007-1029 ◽  
Author(s):  
M. Krauzman ◽  
A. Colline ◽  
D. Kirin ◽  
R. M. Pick ◽  
N. Toupry
Keyword(s):  
Phase Transition ◽  
Incommensurate Phase ◽  
Raman Study ◽  
Polarized Raman

Temperature-dependent study of GaAs1−x−y N x Bi y alloys for band-gap engineering: photoreflectance and k · p modeling

2020 ◽  
Vol 13 (9) ◽  
pp. 091005
Author(s):  
Wiktor Żuraw ◽  
Wojciech M. Linhart ◽  
Jordan Occena ◽  
Tim Jen ◽  
Jared. W. Mitchell ◽  
...  
Keyword(s):  
Band Gap ◽  
Temperature Dependent ◽  
Band Gap Engineering ◽  
Temperature Dependent Study
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