Enhancing polarization by electrode-controlled strain relaxation in PbTiO₃ heterostructures

Abstract A large remanent polarization close to theoretical value 80 𝜇C/cm² of bulk PbTiO₃ is achieved in epitaxial heterostructures of (120–600)-nm-thick PbTiO₃ films grown by pulsed laser deposition on (001) SrTiO₃ substrate using a 100-nm-thick SrRuO₃ bottom electrode layer. The heterostructures employing a 50-nm-thick electrode exhibit a significantly smaller polarization of ≤60 𝜇C/cm². A detailed x-ray diffraction analysis of the crystal structure allows for relating this large polarization to electrode-controlled relaxation of epitaxial strain in PbTiO₃. Based on the observed results, we anticipate that the electrode-promoted strain relaxation can be used to enhance polarization in other epitaxial ferroelectric films. Erratum: “Enhancing polarization by electrode-controlled strain relaxation in PbTiO₃ heterostructures” [APL Mater. 4, 016104 (2016)], APL Materials 5, 029901 (2017); doi: http://dx.doi.org/10.1063/1.497565