Suppressed dependence of polarization on epitaxial strain in highly polar ferroelectrics

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.98.217602· OSTI ID:931472

Lee, Ho Nyung ^[1]; Nakhmanson, Dr. Serge M. ^[2]; Chisholm, Matthew F ^[1]; Christen, Hans M ^[1]; Rabe, Karin M. ^[2]; Vandebilt, David ^[2]

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1. ORNL
2. Rutgers University

A combined experimental and computational investigation of coupling between polarization and epitaxial strain in highly polar ferroelectric PbZr{sub 0.2}Ti{sub 0.8}O{sub 3} (PZT) thin films is reported. A comparison of the properties of relaxed (tetragonality c/a{approx}1.05) and highly strained (c/a{approx}1.09) epitaxial films shows that polarization, while being amongst the highest reported for PZT or PbTiO3 in either film or bulk forms Pr{approx}82{micro}C/cm{sup 2}, is almost independent of the epitaxial strain. We attribute this behavior to a suppressed sensitivity of the A-site cations to epitaxial strain in these Pb-based perovskites, where the ferroelectric displacements are already large, contrary to the case of less polar perovskites, such as BaTiO{sub 3}. In the latter case, the A-site cation (Ba) and equatorial oxygen displacements can lead to substantial polarization increases.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 931472
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Vol. 98; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
EPITAXY
PEROVSKITES
POLARIZATION
PZT
SENSITIVITY
STRAINS
THIN FILMS