Reference : Finite-strain Landau theory applied to the high-pressure phase transition of lead titanate
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Physics
Physics and Materials Science
http://hdl.handle.net/10993/40039
Finite-strain Landau theory applied to the high-pressure phase transition of lead titanate
English
Troester, A. [> >]
Ehsan, S. [> >]
Belbase, K. [> >]
Blaha, P. [> >]
Kreisel, Jens mailto [University of Luxembourg > Rectorate >]
Schranz, W. [> >]
2017
PHYSICAL REVIEW B
95
6
Yes
International
2469-9950
[en] Standard Landau theory coupled to infinitesimal strain allows a concise description of the temperature-driven ferroelectric tetragonal-to-cubic phase transition in PbTiO3 at ambient pressure. Unfortunately, it fails to cover its high-pressure counterpart at ambient temperature. For example, the experimental transition pressure is vastly underestimated and neither the change from first to second order with increasing pressure nor the unusual pressure dependence of the tetragonal unit cell parameters observed in experiment are reproduced. Here we demonstrate that a combination of density functional theory and a recently constructed finite-strain extension of Landau theory provides a natural mechanism for resolving these discrepancies between theory and experiment. Our approach also allows us to determine the full tetragonal-cubic phase boundary in the (P,T) plane including an estimate of the tricritical point. We show that a careful analysis of the thermal elastic baseline is an essential ingredient to the success of this theory.
http://hdl.handle.net/10993/40039
10.1103/PhysRevB.95.064111 064111

File(s) associated to this reference

Fulltext file(s):

FileCommentaryVersionSizeAccess
Limited access
PRB_PTO_Landau_Finite_Strain_2017.pdfPublisher postprint794.13 kBRequest a copy

Bookmark and Share SFX Query

All documents in ORBilu are protected by a user license.