abstract
Bismuth-based oxides with chemical formula ABiO(3), where A = Ca, Zn, Mg, have been recently synthesized and suggested to host ferroelectricity. As these materials possess favorable optical properties, the presence of ferroelectricity with large polarization would further enhance the possible applications, for example, in photovoltaics by improving the separation of charge carriers. In this work, first-principles Density Functional Theory (DFT) calculations are performed to study the relative stability of the different polymorphs and to investigate the structural, electronic, and ferroelectric properties. Furthermore, the effect of compressive and tensile in-plane strain on the polarization and electronic properties is also considered. Our study suggests that CaBiO3 should have a large electric polarization (1.8 C/m(2)) comparable to the one of BiFeO3. Interestingly, the very high polarization appears with only slightly anomalous values of Born effective charges, which would point out a dominant ionic contribution. Our results call for further studies, both from experimental and theoretical sides, to confirm the large electric polarization CaBiO3 predicted in this work. For ZnBiO3 and MgBiO3, we have demonstrated that, up to large values of strain, the perovskite structure retains favorable ferroelectric and electronic (band gap) properties.
subject category
Crystallography; Materials Science
authors
Rus, FS; Goncalves, JN
our authors
João Nuno Santos Gonçalves
Junior Researcheracknowledgements
This work was performed under the project HPC-EUROPA3 (INFRAIA-2016-1-730897) with the support of the EC Research Innovation Action under the H2020 Programme; the authors gratefully acknowledge the support of Alessandro Stroppa and the hospitality from CNR-SPIN c/o Departmentof Physical and Chemical Sciences, University of L'Aquila, Via Vetoio, I-67100, Coppito, L'Aquila,Italy. We are grateful for the computer resources and technical support provided by CINECA. J.N.G. worked within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 and UIDP/50011/2020, financed by national funds through the Portuguese Foundation for Science and Technology/MCTES