APS March Meeting 2017
Volume 62, Number 4
Monday–Friday, March 13–17, 2017;
New Orleans, Louisiana
Session L37a: Dielectric and Ferroelectric Oxides IV
11:15 AM–2:15 PM,
Wednesday, March 15, 2017
Room: 383
Sponsoring
Unit:
DMP
Chair: Tomas Zac Ward, Oak Ridge National Laboratory
Abstract ID: BAPS.2017.MAR.L37a.1
Abstract: L37a.00001 : Multiferroic phase boundaries and properties of BiFeO$_{\mathrm{3}}$-based solid solutions*
11:15 AM–11:51 AM
Preview Abstract
Abstract
Author:
Zuo-Guang Ye
(Simon Fraser University)
The presence of morphotropic phase boundary in ferroelectric solid solutions
(FE-MPB) is known to be crucial for high piezoelectricity. Similarly,
magnetic MPB (M-MPB) is found in a few ferromagnets and is proved to be
greatly beneficial to the magnetostricitive response. One naturally asks if
in multiferroics that exhibit both ferroelectricity and
(ferro-/antiferro-)magnetism, the FE-MPB and M-MPB could exist
simultaneously, and if so, what the relation between these two kinds of MPB
would be, and how they would affect the properties. In this paper, we report
the studies of ferroelectric and magnetic double morphotropic phase
boundaries in BiFeO$_{\mathrm{3}}$-based multiferroics.
The effects of dysprosium ion on the structure and local polar domains of
the BiFeO$_{\mathrm{3}}$-based systems were investigated firstly in the
Dy-substituted solid solutions of
0.66Bi$_{\mathrm{1-}}_{x}$Dy$_{x}$FeO$_{\mathrm{3}}$-0.34PbTiO$_{\mathrm{3}}$.
It is found that the substitution of Dy affects the structural symmetry and
phase component of the multiferroic solid solution, and thereby enhances its
ferroelectric order. A (weak) ferromagnetic state is induced at room
temperature for the rhombohedral compositions with $x \quad \ge $ 0.10. The
introduction of Dy into 0.66BiFeO$_{\mathrm{3}}$-0.34PbTiO$_{\mathrm{3}}$
leads to the breaking of its antiferromagnetic order below N\'{e}el
temperature and thereby the formation of (weak) ferromagnetic ordering at
room temperature when the substitution rate exceeds a critical value ($x \quad \ge
$ 0.10), making the
0.66Bi$_{\mathrm{1-}}_{x}$Dy$_{x}$FeO$_{\mathrm{3}}$-0.34PbTiO$_{\mathrm{3}}$
system one of rare room-temperature ferromagnetic and ferroelectric
materials, i.e. a true multifrroic.
A comprehensive ferroelectric-magnetic phase diagram is established in terms
of temperature and composition, which depicts the coexistence of a FE-MPB
and a FM-MPB. These two kinds of MPBs overlap with each other. Such unusual
coincidence of both magnetic MPB and ferroelectric MPB, the so-called double
MPB, points to new kinds of couplings among the multiple physical quantities
so that such effects as magnetoelectricity, magnetostrictive and
piezoelectricity, could be enhanced near the overlapping MPB region.
In addition, we find an unusual magnetic pole inversion behavior in
mutiferroic (1-x)BiFeO$_{\mathrm{3}}$-xDyFeO$_{\mathrm{3}}$ solid solution,
which can be tuned by varying the concentration of the magnetic ion
Dy$^{\mathrm{3+}}$ in the solid solution in a wide composition range.
*The work was supported by the U.S. Office of Naval Research (Grants No. N00014-12-1-1045 \& N00014-16-1-3106) and the Natural Science \& Engineering Research Council of Canada (NSERC).
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2017.MAR.L37a.1