Electronic and Polar Properties of Vanadate Compounds
Stabilized by Epitaxial Strain
Thomas Angsten
Lane W. Martin
Mark Asta
10.1021/acs.chemmater.8b01499.s003
https://acs.figshare.com/articles/dataset/Electronic_and_Polar_Properties_of_Vanadate_Compounds_Stabilized_by_Epitaxial_Strain/7005851
Recent
experimental and computational studies have demonstrated
pressure and epitaxial stabilization of polar PbVO<sub>3</sub> phases
with perovskite-derivative crystal structures. In this study, we demonstrate,
by density functional theory (DFT) calculations, the stability of
similar perovskite-derivative structures in the KVO<sub>3</sub> and
NaVO<sub>3</sub> systems when subjected to compressive biaxial strain.
The electronic structure and polar properties of these compounds are
computed as a function of biaxial strain, and the results are compared
to those obtained for experimentally observed PbVO<sub>3</sub> structures.
It is demonstrated that the substitution of Pb with monovalent K or
Na cations increases the strength of the vanadyl bond due to the removal
of the spatially extended Pb 6p states. Both KVO<sub>3</sub> and NaVO<sub>3</sub> exhibit epitaxially stabilized perovskite-derivative phases
having large polarizations and only small total energy increases relative
to their unstrained bulk structures. The calculated epitaxial phase
diagram for KVO<sub>3</sub> predicts a strain-energy driving force
for a phase separation from −4% to 1.5% misfit strain into
a polar <i>Cm</i> phase, having square-pyramidal coordination
of the <i>B</i>-site, and a paraelectric <i>Pbcm</i> phase, having tetrahedral coordination of the <i>B</i>-site. The results show that strain-stabilized polar vanadate compounds
may occur for other compositions in addition to PbVO<sub>3</sub> and
that changes in the <i>A</i>-site species can be used to
tune bonding, structure, and functional properties in these systems.
2018-08-10 00:00:00
NaVO 3 exhibit epitaxially
Pb 6 p states
biaxial strain
Na cations increases
epitaxial phase diagram
KVO 3
PbVO 3 phases
PbVO 3 structures
Vanadate Compounds Stabilized
unstrained bulk structures
perovskite-derivative crystal structures
DFT
site
NaVO 3 systems
paraelectric Pbcm phase