Theory and Neutrons Combine to Reveal A Family of Layered Perovskites Without Inversion Symmetry

DOI: 10.1021/acs.chemmater.7b03604

Authors: Tong Zhu (University of Oxford) , Toby Cohen (University of Oxford) , Alexandra Gibbs (ISIS Facility) , Weiguo Zhang (University of Houston) , P. Shiv Halasyamani (University of Houston) , Michael Hayward (University of Oxford) , Nicole A. Benedek (Cornell University)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemistry Of Materials

State: Published (Approved)
Published: October 2017
Diamond Proposal Number(s): 13284

Abstract: A flurry of recent theoretical studies have predicted the existence of new polar materials among several families of layered perovskites, including the double-layered Dion-Jacobson phases. These predictions have opened up exciting new opportunities for both fundamental studies of the crystal chemistry of Dion-Jacobson phases, and for their application as components in next-generation memories and low-power electronic devices. However, with some rare exceptions, all known double-layered Dion-Jacobson phases are nonpolar. We use an integrated theoretical-experimental approach to show that several Dion-Jacobson phases that have previously been synthesized and characterized as nonpolar are in fact polar. Additional theoretical calculations reveal that the polar phases of these materials emerge through a hybrid improper or trilinear coupling mechanism. Finally, our work has highlighted the critical role of neutron diffraction in characterizing the structures of double-layered Dion-Jacobson phases, which are typified by subtle oxygen atom displacements not easily resolved using even synchrotron X-ray diffraction.

Subject Areas: Chemistry, Materials


Instruments: I11-High Resolution Powder Diffraction