First Principles Based Simulations of Relaxor Ferroelectrics

Published

January 16, 2006

Author(s)

Benjamin P. Burton, Eric J. Cockayne, Silvia Tinte, U Waghmare

Abstract

The phenomenology of Pb(B,B$ {\prime}$)O$_{3}$, perovskite based relaxor ferroelectrics is reviewed, with emphasis on the relationship between chemical short-range order and the formation of polar nanoregions in the temperature range between the freezing temperature, $T_{f}$, and the Burns temperature, $T_$. Results are presented for first-principles based effective Hamiltonian simulations of $Pb(Sc_1⁄2 ) O_3$ (PSN), and simulations of $Pb (Mg_{1/3}Nb_{2/3} ) O_3$ (PMN), that wer done via empirical modifications of the PSN Hamiltonian. Increasing the magnitudes of local electric fields, caused {\it e.g.} by an increase in chemical disorder, broadens the dielectric peak, and reduces the ferroelectric transition temperature. Sufficiently strong local fields suppress the transition. Similar, but more dramatically glassy results are obtained by using the PSN dielectric model with a distribution of local fields that is appropriate for PMN. The results of these simulations, and reviewed experimental data, strongly support the view that within the range $T_{f} ~

Citation

Phase Transitions

Volume

79

Pub Type

Journals

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Keywords

$Pb (Mg_{1/3}Nb_{2/3} ) O_3$, phase transitions, polar nano-regions, PSN, relaxor ferroelectrics, short range order

Citation

Burton, B. , Cockayne, E. , Tinte, S. and Waghmare, U. (2006), First Principles Based Simulations of Relaxor Ferroelectrics, Phase Transitions, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=850911 (Accessed April 26, 2024)