Single-domain (110) PbTiO3 thin films: Thermodynamic theory and experiments

P Mtebwa (1) , P K Tagantsev (1) , T Yamada (2, 3) , N Setter (1) , P. Gemeiner (4) , B. Dkhil (4)

1 EPFL - Ecole Polytechnique Fédérale de Lausanne
2 Department of materials, Physics and energy Engineering
3 PRESTO
4 SPMS - Laboratoire Structures, Propriétés et Modélisation des solides

We report the thermodynamic potential for single-domain (110) thin films epitaxially grown on dissimilar cubic substrates. Using different sets of paraelectric phase elastic compliance coefficients of PbTiO 3 single crystal, calculated from the experimental room-temperature values, we predict rotational phases similar to those observed in (001) thin films under anisotropic biaxial misfit strain. The new sets of elastic compliance coefficients also predict a triclinic phase that could potentially lead to the enhancement of both dielectric and piezoelectric properties. We also conducted experimental studies on highly tetragonal monocrystalline PbZr 0.05 Ti 0.95 O 3 thin films of different thicknesses, epitaxially grown on (110) SrTiO 3 substrate by pulsed laser deposition technique. Piezoresponse force microscopy measurements showed that the as-grown films were single domain with the a 2 c phase, which corroborates with the prediction of the theory. Moreover, the T c values of both thin and thick films (17–90 nm) also fell within the predicted range (540–600 ± • C). The measured remanet polarization of 57 µC/cm 2 was in good agreement with the theoretical values of 55–58 µC/cm 2. Small-signal piezoelectric response measurements gave a piezoelectric coefficient of 40 pm/V, which is also in good agreement with the numerically calculated values of 38–42 pm/V.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

P Mtebwa, P K Tagantsev, T Yamada, N Setter, P. Gemeiner, et al.. Single-domain (110) PbTiO3 thin films: Thermodynamic theory and experiments. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2016, 93, pp.144113. ⟨10.1103/PhysRevB.93.144113⟩. ⟨hal-01385363⟩