Ferroelectricity and tetragonality in ultrathin PbTiO3 films

[en] The evolution of tetragonality with thickness has been probed in epitaxial c-axis oriented PbTiO3 films with thicknesses ranging from 500 down to 24 Angstrom. High resolution x ray pointed out a systematic decrease of the c-axis lattice parameter with decreasing film thickness below 200 Angstrom. Using a first-principles model Hamiltonian approach, the decrease in tetragonality is related to a reduction of the polarization attributed to the presence of a residual unscreened depolarizing field. It is shown that films below 50 Angstrom display a significantly reduced polarization but still remain ferroelectric.

Disciplines :

Physics

Author, co-author :

Lichtensteiger, C.

Triscone, J. M.

Junquera, J.

Ghosez, Philippe ; Université de Liège - ULiège > Département de physique > Physique théorique des matériaux

Language :

English

Title :

Ferroelectricity and tetragonality in ultrathin PbTiO3 films

Publication date :

2005

Journal title :

Physical Review Letters

ISSN :

0031-9007

eISSN :

1079-7114

Publisher :

American Physical Society, Ridge, United States - New York

Volume :

Pages :

047603

Peer reviewed :

Peer Reviewed verified by ORBi

Available on ORBi :

since 02 December 2009

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