Covalent effects in magnetic ferroelectrics MnMO3 (M = Ti, Sn)

Author(s)
Xianfeng Hao, Yuanhui Xu, Cesare Franchini, Faming Gao
Abstract

By means of first-principles calculations based on density functional theory (DFT), DFT+U and hybrid functional methods, we report a comparative study of the magnetic, electronic, and ferroelectric properties of high-pressure-induced compounds MnMO3 (M=Ti, Sn). The results correctly describe the insulating character and G-type antiferromagnetic ground state for both compounds, which is in good agreement with the experimental observations. We predicted large spontaneous ferroelectric polarizations of MnTiO3 and MnSnO3 by using the Berry-phase method. In particular, the proper covalent interaction mechanism driving the ferroelectric transition is discussed and explained in term of the analysis of potential-energy surfaces, Born effective charges, and electric localization function. Our results indicate that MnTiO3 and MnSnO3 represent unique examples of ferroelectric perovskites in which the ferroelectric instabilities originate from the combined action of geometric effects and chemical activity of the B-site atom, thus extending the concept of d(0)-ness (MnTiO3) and lone-pair mechanism (MnSnO3) to magnetic ferroelectrics.

Organisation(s)
Computational Materials Physics
External organisation(s)
Yanshan University
Journal
Physica Status Solidi. B: Basic Research
Volume
252
Pages
626-634
No. of pages
9
ISSN
0370-1972
DOI
https://doi.org/10.1002/pssb.201451476
Publication date
03-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
103025 Quantum mechanics, 103036 Theoretical physics, 103015 Condensed matter, 103009 Solid state physics
Keywords
ASJC Scopus subject areas
Electronic, Optical and Magnetic Materials, Condensed Matter Physics
Portal url
https://ucrisportal.univie.ac.at/en/publications/72bace76-ce07-47af-809f-2758f4f2697d