Molecular Dynamics Study of Dielectric Response in a Relaxor Ferroelectric

Grinberg, Ilya; Shin, Young‐Han; Rappe, Andrew M.

doi:10.1103/physrevlett.103.197601

Cited by 63 publications

(43 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Contrary to what is believed, we show that behavior of PMN can be explained without the presence of PNRs. Recent MD simulations were able to describe the dielectric response of the relaxor PMN-0.25PT without PNRs [17], so both results raise the question about the precise role played by PNRs in the relaxor behavior [25], 0.1 [6], 0.2 [26], 0.3 [5], 0.39 [5], 0.5 [12], 0.65 [12] and 1 [27], and LDA results from PMN and PT. [55].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

First-principles based atomistic modeling of phase stability in PMN–xPT

Sepliarsky¹,

Cohen²

2011

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Abstract.We have performed molecular dynamics simulations using a shell model potential developed by fitting first principles results to describe the behavior of the relaxorferroelectric (1-x)PbMg 1/3 Nb 2/3 O 3 -xPbTiO 3 (PMN-xPT) as function of concentration and temperature, using site occupancies within the random site model. In our simulations, PMN is cubic at all temperatures and behaves as a polar glass. As a small amount of Ti is added, a weak polar state develops, but structural disorder dominates, and the symmetry is rhombohedral. As more Ti is added the ground state is clearly polar and the system is ferroelectric, but with easy rotation of the polarization direction. In the high Ti content region, the solid solution adopts ferroelectric behavior similar to PT, with tetragonal symmetry. The ground state sequence with increasing Ti content is R-M B -O-M C -T. The high temperature phase is cubic at all compositions. Our simulations give the slope of the morphotropic phase boundaries, crucial for high temperature applications. We find that the phase diagram PMN-xPT can be understood within the random site model.

show abstract

Section: Discussionmentioning

confidence: 99%

“…[13] The existence of PNRs in relaxors is a basic assumption of several models describing relaxor behavior [14][15][16]. Recent results, however, show that some essential features of the dielectric response in relaxors can be driven by local phenomena without the requirement of PNRs [17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

First-principles based atomistic modeling of phase stability in PMN–xPT

Sepliarsky¹,

Cohen²

2011

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

show abstract

“…Ferroelectric (FE) and related materials are of great importance for many device applications 1 . For some of these applications and for fundamental reasons, the dynamical properties of these materials need to be determined and understood, especially when realizing that surprises can be in store when they are investigated [2][3][4][5][6][7][8][9] . For instance, some recent studies discovered that BaTiO 3 has two (rather than one, as believed for more than 30 years) modes contributing to its dielectric response in the THz range, both in the paraelectric and FE tetragonal phases 2,3 .…”

Section: Jirka Hlinkamentioning

confidence: 99%

Dynamical coupling inPb(Zr,Ti)O3solid solutions from first principles

et al. 2011

View full text Add to dashboard Cite

“…We study an 8640-atom supercell of PMN-PT with bond-valence (BV) MD simulations [12,13] in this work. .…”

mentioning

confidence: 99%

Anisotropic Local Correlations and Dynamics in a Relaxor Ferroelectric

2013

Self Cite

View full text Add to dashboard Cite

Relaxor ferroelectrics have been a focus of intense attention due to their anomalous dielectric characteristics, diffuse phase transitions, and strong piezoelectricity. Understanding the structure and dynamics of relaxors has been one of the long-standing challenges in solid-state physics, with the current model of polar nanoregions in a non-polar matrix providing only a qualitative description of the relaxor phase transitions. In this paper, we investigate the local structure and dynamics in 75%PbMg 1/3 Nb 2/3 O3-25%PbTiO3 (PMN-PT) using molecular dynamics simulations and the dynamic pair distribution function technique. We show for the first time that relaxor transitions can be described by local order parameters. We find that structurally, the relaxor phase is characterized by the presence of highly anisotropic correlations between the local cation displacements. These correlations resemble the hydrogen bond network in water. Our findings contradict the current polar nanoregion model; instead, we suggest a new model of a homogeneous random network of anisotropically coupled dipoles.

show abstract

Molecular Dynamics Study of Dielectric Response in a Relaxor Ferroelectric

Cited by 63 publications

References 17 publications

First-principles based atomistic modeling of phase stability in PMN–xPT

First-principles based atomistic modeling of phase stability in PMN–xPT

Dynamical coupling inPb(Zr,Ti)O3solid solutions from first principles

Anisotropic Local Correlations and Dynamics in a Relaxor Ferroelectric

Contact Info

Product

Resources

About