Electromechanical Properties of Ba(1-x)SrxTiO3 Perovskite Solid Solutions from First-Principles Calculations

Leonid L Rusevich; Guntars Zvejnieks; Alessandro Erba; Roberto Dovesi; Eugene A Kotomin

doi:10.1021/acs.jpca.7b08473

Electromechanical Properties of Ba_(1-x)Sr_xTiO₃ Perovskite Solid Solutions from First-Principles Calculations

J Phys Chem A. 2017 Dec 14;121(49):9409-9414. doi: 10.1021/acs.jpca.7b08473. Epub 2017 Dec 1.

Authors

Leonid L Rusevich^{1

2}, Guntars Zvejnieks¹, Alessandro Erba³, Roberto Dovesi³, Eugene A Kotomin¹

Affiliations

¹ Institute of Solid State Physics, University of Latvia , 8 Kengaraga str., Riga LV-1063, Latvia.
² Institute of Physical Energetics , 11 Krivu str., Riga LV-1006, Latvia.
³ Dipartimento di Chimica, Università degli Studi di Torino , via Giuria 5, I-10125 Torino, Italy.

PMID: 29148772
DOI: 10.1021/acs.jpca.7b08473

Abstract

An enhancement of the piezoelectric properties of lead-free materials, which allow conversion of mechanical energy into electricity, is a task of great importance and interest. Results of first-principles calculations of piezoelectric/electromechanical properties of the Ba_(1-x)Sr_xTiO₃ (BSTO) ferroelectric solid solution with a perovskite structure are presented and discussed. Calculations are performed within the linear combination of atomic orbitals (LCAO) approximation and periodic-boundary conditions, using the advanced hybrid functionals of density functional theory (DFT). A supercell model allows the investigation of multiple chemical compositions x. In particular, three BSTO solid solutions with x = 0, 0.125, 0.25 are considered within the experimental stability domain of the ferroelectric tetragonal phase of the solid solution (x < 0.3). The configurational disorder with x = 0.25 composition is also investigated explicitly considering the seven possible atomic configurations corresponding to this composition. It is predicted that Sr-doping of BaTiO₃ makes it mechanically harder and enhances its electromechanical/piezoelectric properties, which are important for relevant applications.