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

Autor(en)

Xianfeng Hao, Yuanhui Xu, Cesare Franchini, Faming Gao

Abstrakt

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(en)

Computergestützte Materialphysik

Externe Organisation(en)

Yanshan University

Journal

Physica Status Solidi. B: Basic Research

Band

252

Seiten

626-634

Anzahl der Seiten

9

ISSN

0370-1972

DOI

https://doi.org/10.1002/pssb.201451476

Publikationsdatum

03-2015

Peer-reviewed

Ja

ÖFOS 2012

103025 Quantenmechanik, 103036 Theoretische Physik, 103015 Kondensierte Materie, 103009 Festkörperphysik

Schlagwörter

ASJC Scopus Sachgebiete

Electronic, Optical and Magnetic Materials, Condensed Matter Physics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/72bace76-ce07-47af-809f-2758f4f2697d