First-principles free energies and Ginzburg-Landau theory of domains and ferroelectric phase transitions inBaTiO3

2010 ◽  
Vol 82 (5) ◽  
Author(s):  
Anil Kumar ◽  
Umesh V. Waghmare
Keyword(s):  
Phase Transitions ◽  
First Principles ◽  
Ferroelectric Phase ◽  
Landau Theory ◽  
Free Energies ◽  
Ginzburg Landau ◽  
Ferroelectric Phase Transitions

Recent Applications of Landau-Ginzburg Theory to Ferroelectric Superlattices: A Review

2012 ◽  
Vol 189 ◽  
pp. 145-167 ◽  
Author(s):  
Khian Hooi Chew
Keyword(s):  
Phase Transitions ◽  
First Principles ◽  
Type Theory ◽  
Ferroelectric Phase ◽  
Review Article ◽  
First Principles Calculations ◽  
Emergent Phenomena ◽  
Recent Developments ◽  
Local Polarization ◽  
Ferroelectric Phase Transitions

This article briefly reviews recent developments of Landau-Ginzburg theory to ferroelectric phase transitions in superlattices. An overview of the contributions of Landau-type theory to study ferroelectric superlattices is given. Recent findings from first-principles calculations and experiments on intermixing, local polarization coupling and polar discontinuity at interfaces that are not address in these contributions are highlighted. This is followed by a review of recent developments of Landau-Ginzburg theory that addresses these emergent phenomena at interfaces, which is the focus of this review article. The Landau-Ginzburg approach to ferroelectric superlattices with spatial distribution of polarization is outlined. It describes the formation of intermixed layer with properties different from those of both layers. These intermixed layers are mutually coupled through the local polarization at interfaces. Polarization continuity or continuity at interfaces is determined by the nature of the intermixed layer formed at the interface region. Recent results obtained in investigating superlattices comprised primarily of ferroelectric and paraelectric materials are discussed. The results include modulated polarizations, phase transitions, dielectric susceptibilities and switching behaviors.

MULTIPLE PHASE TRANSITIONS IN PEROVSKITE STRUCTURE CERAMICS: STRUCTURAL TRANSITIONS

1999 ◽  
Vol 13 (22n23) ◽  
pp. 791-799
Author(s):  
C. H. EAB ◽  
B. WIWATANAPATAPHEE ◽  
I. M. TANG
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Structural Phase Transition ◽  
Perovskite Structure ◽  
Landau Theory ◽  
Structural Phase ◽  
Free Energies ◽  
Ginzburg Landau ◽  
First Order ◽  
Multiple Phase

A Ginzburg–Landau theory for the multiple structural phase transition observed in the cuprate perovskite structure ceramics is developed. The order parameters Λi for each phase are defined in terms of the deformations which occur in each phase. In terms of the deformation, the expansion of the free energies is to the twelfth order. The theory can account for a second-order tetragonal to orthorhombic-I transition at high temperatures and a first-order orthorhombic-I to orthorhombic-II transition at lower temperatures. The criterion for the existence of a tricritical line is established.

Sign in / Sign up

Export Citation Format

Share Document