This document discusses multiferoic materials, which exhibit more than one "primary ferroic order parameter" simultaneously. The four primary ferroic order parameters are ferromagnetism, ferroelectricity, ferroelasticity, and antiferromagnetism/ferrimagnetism. The document provides examples of natural and synthetic multiferoic materials and discusses their properties and applications. It also explains related effects like magnetoelectricity and piezoelectricity, describing how certain materials can generate an electric potential or mechanical strain in response to a magnetic or electric field.
2. WHAT IS MULTIFERROICS ?
• MULTIFERROICS HAVE BEEN FORMALLY DEFINED AS MATERIALS THAT EXHIBIT
MORE THAN ONE PRIMARY FERROIC ORDER PARAMETER SIMULTANEOUSLY (I.E.
IN A SINGLE PHASE).HOWEVER, THE DEFINITION OF MULTIFERROICS CAN BE
EXPANDED TO INCLUDE NON-PRIMARY ORDER PARAMETERS, SUCH
AS ANTIFERROMAGNETISM OR FERRIMAGNETISM.
THE FOUR BASIC PRIMARY FERROIC ORDER PARAMETERS ARE
• FERROMAGNETISM
• FERROELECTRICITY
• FERROELASTICITY
• REF:HTTPS://EN.WIKIPEDIA.ORG/WIKI/MULTIFERROICS
7. MULTIFERROICS & MAGNETOELECTRIC EFFECT
• Simultaneous breaking of time reversal and spatioal inversion
• Plenty of multiferroics even room-temperature ones!
• In hand: Ba2CoGe2O7 , Ca2CoSi2O7 , NdFe3(BO3)4 , TbFe3(BO3)4
,CoCr2O4 , FeCr2O4 , MnCr2O4, NiV3O8
P. Curie, Journal de Physique 3, 393 (1894)
„Materials should exist, which can be polarized by a magnetic field and magnetized via an electric
field.”
8. Multiferroic state of Ba2CoGe2O7
[010]
[001]
[100]
21
m[110]
[001]
[010]
[100]
4
Ba
Co
Ge
O
P421m
i×4 =
• Tetragonal noncentrosymmetric crystal structure V. Hutanu et al., Phys. Rev. B 84,
212101 (2011)
• Magetic Co2+ ions with S=3/2 in tetrahedral oxygen cages
• Easy-plane Néel antiferromagnet V. Hutanu ... and I. Kézsmárki, Phys. Rev. B 86, 104401 (2012)
9. Multiferroics were considered to be rare because magnetism and ferroelectricity
require entirely different criteria for the materials. Several multiferroic oxides have,
however, been discovered in the past few years by virtue of novel operating
mechanisms, the most effective one being ferroelectricity driven by magnetism
itself. Many such oxides where the magnetic and electric order parameters interact
also exhibit magnetoelectric or magnetodielectric properties. Multiferroic properties
arising from charge ordering are examined. The present status of BiMnO3, which
is an unusual example of a ferromagnetic−ferroelectric, is presented. Some of the
recent examples of magnetically induced ferroelctricity are TbMnO3, GdFeO3,
SmFeO3
Cpubs.acs.org/JPCL N. R. Rao,* A. Sundaresan, and Rana Saha
10. In recent years, there has been remarkable interest in the synthesis and
investigation of hybrid organic−inorganic materials, such as the metal−organic
frameworks (MOFs), largely due to their potential applications in gas storage,
catalysis, nonlinear optics, photoluminescence, and solar cells as well as their
intriguing magnetic and electric properties for fundamental science study
Compared with inorganic multiferroic materials of transition metal oxides, the
ME effects in multiferroic MOFs are very weak and even undetectable because
their electric and magnetic orders usually have different origins. Only recently
reported MOF which has the ME effects in the multiferroic state of the
perovskite MOF [(CH3)2NH2]Fe(HCOO)3 (FeMOF).
pubs.acs.org/JACS Ying Tian, Shipeng Shen, Junzhuang Cong, Liqin Yan, Shouguo Wang, and Young Sun*
13. • Piezoelectric Material will generate electric potential when subjected to
some kind of mechanical stress. Pierre Curie and Jacqueus Curie
(brothers) discovered the piezoelectric effect in 1880.
14. Gabriel Lippmann in the year 1881 deduced mathematically the inverse
piezoelectric effect from fundamental thermodynamic principles. The Curie
brothers experimentally verified the existence of the inverse piezoelectric effect.
In the inverse piezoelectric effect, an electric field is applied to a material to
generate mechanical deformations
15. • A traditional piezoelectric ceramic is a mass of perovskite
crystals. Each crystal consists of a small tetravalent metal
ion, usually titanium or zirconium, in a lattice of larger
divalent metal ions, usually lead or barium, and O2- ions
• At temperatures below the Curie point, however, each
crystal has tetragonal or rhombohedral symmetry and a
dipole moment. Above the Curie point each perovskite
crystal in the fired ceramic element exhibits a cubic
symmetry with no dipole moment.
16. • Naturally occurring crystals:
Berlinite (AlPO4), cane sugar, Quartz, Rochelle salt, Topaz, Tourmaline Group
Minerals, and dry bone (apatite crystals)
• Man-made crystals:
Gallium orthophosphate (GaPO4), Langasite (La3Ga5SiO14)
• Man-made ceramics:
Barium titanate (BaTiO3), Lead titanate (PbTiO3), Lead zirconate titanate
(Pb[ZrxTi1-x]O3 0<x<1) - More commonly known as PZT, Potassium niobate
(KNbO3), Lithium niobate (LiNbO3), Lithium tantalate (LiTaO3), Sodium
tungstate (NaxWO3), Ba2NaNb5O5, Pb2KNb5O15
• Polymers:
Polyvinylidene fluoride (PVDF)
17. This is a mechanism, a piezoelectrochemical effect for the direct
conversion of mechanical energy to chemical energy. This
phenomenon is further applied for generating hydrogen and oxygen
via direct water decomposition by means of as-synthesized
piezoelectric ZnO microfibers and BaTiO3 microdendrites. Fibers and
dendrites are vibrated with ultrasonic waves leading to a strain-
induced electric charge development on their surface. With sufficient
electric potential, strained piezoelectric fibers (and dendrites) in water
triggeredthe redox reaction of water to produce hydrogen and oxygen
gases. ZnO fibersunder ultrasonic vibrations showed a stoichiometric
ratio of H2/O2 (2:1) initial gasproduction from pure water. This study
provides a simple and cost-effectivetechnology for direct water
splitting that may generate hydrogen fuels by scavenging energy
wastes such as noise or stray vibrations from the environment.
pubs.acs.org/JPCL Kuang-Sheng Hong,† Huifang Xu,*,† Hiromi Konishi,† and Xiaochun Li