Tunability of the dielectric response of epitaxially strained SrTiO3 from first principles

By A. Antons, Jeffrey B. Neaton, K. Rabe, D. V. D. O. Physics, Astronomy, Rutgers University, Nj, Iff Juelich, Heidelberg · Germany, Lbnl and 2 more. 2004

157 citations recorded by the source corpus.

The effect of in-plane strain on the nonlinear dielectric properties of SrTiO3 epitaxial thin films is calculated using density-functional theory within the local-density approximation. Motivated by recent experiments, the structure, zone-center phonons, and dielectric properties with and without an external electric field are evaluated for several misfit strains within +-3% of the calculated cubic lattice parameter. In these calculations, the in-plane lattice parameters are fixed, and all remaining structural parameters are permitted to relax. The presence of an external bias is treated approximately by applying a force to each ion proportional to the electric field. After obtaining zero-field ground state structures for various strains, the zone-center phonon frequencies and Born effective charges are computed, yielding the zero-field dielectric response. The dielectric response at finite electric field bias is obtained by computing the field dependence of the structure and polarization using an approximate technique. The results are compared with recent experiments and a previous phenomenological theory. The tunability is found to be strongly dependent on the in-plane lattice parameter, showing markedly different behavior for tensile and compressive strains. Our results are expected to be of use for isolating the role of strain in the tunability of real ultrathin epitaxial films.

Subfields: Electrical and Electronic Engineering, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/1ab125eeeb7f825c9cb4a08f13f5b21dc93daa72

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In Electrical and Electronic Engineering

1. K. Rabe
2. C. Eom
3. Long-qing Chen
4. Darrell Schlom
5. Yu Wang
6. Ho Won Jang
7. M. Dawber
8. John Robertson

In Materials Chemistry

1. K. Rabe
2. Darrell Schlom
3. J. Triscone
4. Long-qing Chen
5. C. Eom
6. M. Dawber
7. S. Streiffer
8. E. Tsymbal

Citations in the corpus

• Modern Physics of Ferroelectrics: Essential Background (2007, methodology): “For SrTiO3, epitaxial strain transforms the bulk paraelectric phase into a ferroelectric [ 35 , 36].”
• Strain Tuning of Ferroelectric Thin Films (2007, methodology): “Superlattice strain and fields can also stabilize nonbulk phases, such as ferroelectric SrTiO3 (20, 133).”
• Tailoring a two-dimensional electron gas at the LaAlO3/SrTiO3 (001) interface by epitaxial strain (2010, background): “perties that control the 2DEG. It has been predicted theoretically that free-standing biaxially strained SrTiO3 under electrical short-circuit boundary conditions can develop an electric polarization (20,21). Compressive strain is predicted to produce an [001] (out-of-plane) polarization, and tensil”