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EN13.08.10 : Relaxor-Ferroelectric Behaviors on Rare Earth Modified Lead Zirconate Titanate

5:00 PM–7:00 PM Apr 5, 2018

PCC North, 300 Level, Exhibit Hall C-E

Description
Mohan Bhattarai1 Alvaro Instan1 Karuna Mishra1 Ram Katiyar1

1, University of Puerto Rico, Rio Piedras, San Juan, Puerto Rico, United States

Dielectric, ferroelectric ordering and phonons in a mixed doped La3+ and Sc3+ (1-y) [PbZr0.53Ti0.47] y[LaxSc1-x]O3-δ for samples with 0.0≤ x≤ 0.08 and fixed y = 0.1 are investigated using dielectric, polarization, and Raman spectroscopic measurements as a function of temperature. The system is stabilized at tetragonal phase for pure (1-y) [PbZr0.53Ti0.47] y[Sc]O3-δ and the tetragonality is reduced when Sc3+ is partially substituted by La3+ (0.0≤ x≤ 0.08 ). The stochiometric of the chemical compositions are examined using energy dispersive x-ray analysis results. A uniform distribution of grains on the surface of the sample is observed from scanning electron micrographs recorded on pellets. For mixed crystal, the temperature dependent dielectric constant exhibits a broad feature in the T-range 100-600 K, measured at different frequencies (102-106 Hz). Upon increasing x, the values of dielectric constant are found to be monotonically increased and lie in the range 280-1800. Well-defined hysteresis loops are found to saturate above 1000 V. However, the loops are found to be progressively slimmer (remnant polarization remain low) with increasing La-composition x. To begin with the Raman spectra are found to be broad at ambient temperature and the presence of several Raman peaks at elevated temperature indicates the existence of disorder activated Raman bands. Based on the broad dielectric features, slim polarization loops, and disorder activated forbidden Raman scattering; the dopant samples are understood on the basis of formation polar nanoregions, which essentially manifested in relaxor behavior.

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