Effect of Diamagnetic A2+ Substitution on the Magnetic and Ferroelectric Properties of the Bi1−xAxFeO3 Multiferroics

2007 ◽  
Vol 1034 ◽  
Author(s):  
V. A. Khomchenko ◽  
D. A. Kiselev ◽  
J. M. Vieira ◽  
Li Jian ◽  
A. M. L. Lopes ◽  
...  
Keyword(s):  
Spin Structure ◽  
Ionic Radius ◽  
Ferroelectric Properties ◽  
Piezoresponse Force Microscopy ◽  
Weak Ferromagnetism ◽  
Force Microscopy ◽  
Microscopy Data ◽  
A Site ◽  
Induced Changes ◽  
Spiral Spin

AbstractInvestigation of crystal structure, magnetic and local ferroelectric properties of the diamagnetically-doped Bi1−xAxFeO3 (A= Ca, Sr, Pb, Ba; x= 0.2, 0.3) ceramic samples has been carried out. It has been shown that the solid solutions have a rhombohedrally distorted perovskite structure described by the space group R3c. Piezoresponse force microscopy data have revealed the existence of the spontaneous ferroelectric polarization in the samples at room temperature. Magnetization measurements have shown that the magnetic state of these compounds is determined by the ionic radius of the substituting elements. A-site substitution with the biggest ionic radius ions has been found to suppress the spiral spin structure of BiFeO3 and to result in the appearance of weak ferromagnetism. The magnetic properties have been discussed in terms of doping- induced changes in the magnetic anisotropy.

Correlation between Ionic Radius of Substituting Element and Magnetic Properties of Bi1-xAxFeO3-x/2 (A= Ca, Sr, Pb, Ba) Multiferroics

2009 ◽  
Vol 152-153 ◽  
pp. 131-134 ◽  
Author(s):  
V.A. Khomchenko ◽  
Michael Kopcewicz ◽  
Armandina M. Lima Lopes ◽  
Yuri G. Pogorelov ◽  
J.P. Araujo ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Spin Structure ◽  
Ionic Radius ◽  
Oxygen Vacancies ◽  
Magnetic State ◽  
Weak Ferromagnetism ◽  
Host Lattice ◽  
A Site ◽  
Spiral Spin

Investigation of crystal structure and magnetic properties of the diamagnetically- substituted Bi1-xAxFeO3-x/2 (A= Ca, Sr, Pb, Ba; x= 0.2, 0.3) polycrystalline samples has been carried out. It has been shown that the heterovalent A2+ substitution result in the formation of oxygen vacancies in the host lattice. The solid solutions have been found to possess a rhombohedrally distorted perovskite structure described by the space group R3c. Magnetization measurements have shown that the magnetic state of these compounds is determined by the ionic radius of the substituting elements. A-site substitution with the biggest ionic radius ions has been found to suppress the spiral spin structure of BiFeO3 giving rise to the appearance of weak ferromagnetism.

scholarly journals Effect of oxidizing and reducing atmospheres on Ba(Ti0.90 Zr0.10)o3:2V ceramics as characterized by piezoresponse force microscopy

2011 ◽  
Vol 5 (3) ◽  
pp. 139-147 ◽  
Author(s):  
Francisco Moura ◽  
Alexandre Simões ◽  
Carla Riccardi ◽  
Maria Zaghete ◽  
Jose Varela ◽  
...  
Keyword(s):  
Data Storage ◽  
Photoelectron Spectroscopy ◽  
Ferroelectric Properties ◽  
Piezoresponse Force Microscopy ◽  
Nitrogen Atmosphere ◽  
Ambient Atmosphere ◽  
Practical Applications ◽  
Force Microscopy ◽  
Storage Media ◽  
Piezoelectric Force Microscopy

The effect of annealing atmospheres (Atamb, N2 and O2) on the electrical properties of Ba(Ti0.90Zr0.10 )O3:2V (BZT10:2V) ceramics obtained by the mixed oxide method was investigated. X-ray photoelectron spectroscopy (XPS) analysis indicates that oxygen vacancies present near Zr and Ti ions reduce ferroelectric properties, especially in samples treated in an ambient atmosphere (Atamb ). BZT10:2V ceramics sintered in a nitrogen atmosphere showed better dielectric behaviour at room temperature with a dielectric permittivity measured at a frequency of 10 kHz equal to 16800 with dielectric loss of 0.023. Piezoelectric force microscopy (PFM) images reveal improvement in the piezoelectric coefficient by sintering the sample under nitrogen atmosphere. Thus, BZT10:2V ceramics sintered under a nitrogen atmosphere can be useful for practical applications which include nonvolatile digital memories, spintronics and data-storage media.

Surface displacements and surface charges on Ba2CuWO6 and Ba2Cu0.5Zn0.5WO6 ceramics induced by local electric fields investigated with scanning-probe microscopy

2007 ◽  
Vol 22 (1) ◽  
pp. 193-200
Author(s):  
Ralf-Peter Herber ◽  
Gerold A. Schneider
Keyword(s):  
Electric Fields ◽  
Ferroelectric Properties ◽  
Piezoresponse Force Microscopy ◽  
Ferroelectric Material ◽  
Relaxor Ferroelectrics ◽  
Surface Charges ◽  
Kelvin Probe ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Displacements

Ba2CuWO6 (BCW) was first synthesized in the mid 1960s, and it was predicted to be a ferroelectric material with a very high Curie temperature of 1200 °C [N. Venevtsev and A.G. Kapyshev: New ferroelectrics. Proc. Int. Meet. Ferroelectr.1, 261 (1966)]. Since then, crystallographic studies were performed on the compound with the result that its crystal structure is centrosymmetric. Thus for principal reason, BCW cannot be ferroelectric. That obvious contradiction was examined in this study. Disk-shaped ceramic samples of BCW and Ba2Cu0.5Zn0.5WO6 (BCZW) were prepared. Because of the low electrical resistivity of the ceramics, it was not possible to perform a typical polariszation hysteresis loop for characterization of ferroelectric properties. Scanning electron microscopy investigations strongly suggest that the reason for the conductivity is found in the impurities/precipitations within the microstructure of the samples. With atomic force microscopy (AFM) in piezoresponse force microscopy (PFM) mode, it is possible to characterize local piezoelectricity by imaging the ferroelectric domains. Neither BCW nor BCZW showed any domain structure. Nevertheless, when local electric fields were applied to the surfaces of the ceramics topographic displacements, imaged with AFM, and surface charges, imaged with Kelvin probe force microscopy (KFM) and PFM, were measured and remained stable on the surface for the time of the experiment. Therefore BCW and BCZW are considered to be electrets and possibly relaxor ferroelectrics.

scholarly journals Structure-resistive property relationships in thin ferroelectric BaTiO$$_{3}$$ films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
N. V. Andreeva ◽  
A. Petraru ◽  
O. Yu. Vilkov ◽  
A. E. Petukhov
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Point Defects ◽  
Ferroelectric Properties ◽  
Piezoresponse Force Microscopy ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Ferroelectric Films ◽  
Force Microscopy ◽  
Atomic Force

Abstract A combined study of local structural, electric and ferroelectric properties of SrTiO$$_{3}$$ 3 /La$$_{0.7}$$ 0.7 Sr$$_{0.3}$$ 0.3 MnO$$_{3}$$ 3 /BaTiO$$_{3}$$ 3 heterostructures was performed by Piezoresponse Force Microscopy, tunneling Atomic Force Microscopy and Scanning Tunneling Microscopy in the temperature range 30–295 K. The direct correlation of film structure (epitaxial, nanocrystalline or polycrystalline) with local electric and ferroelectric properties was observed. For polycrystalline ferroelectric films the predominant polarization state is defined by the peculiarity of screening the built-in field by positively charged point defects. Based on Scanning Tunneling Spectroscopy results, it was found that a sequent voltage application provokes the modification of local resistive properties related to the redistribution of point defects in thin ferroelectric films. A qualitative analysis of acquired Piezoresponse Force Microscopy, tunneling Atomic Force Microscopy and Scanning Tunneling Microscopy images together with Scanning Tunneling Spectroscopy measurements enabled us to conclude that in the presence of structural defects the competing processes of electron injection, trap filling and the drift of positively charged point defects drives the change of resistive properties of thin films under applied electric field. In this paper, we propose a new approach based on Scanning Tunneling Microscopy/Spectroscopy under ultrahigh vacuum conditions to clarify the influence of point defects on local resistive properties of nanometer-thick ferroelectric films.

Microstructure and ferroelectric properties of ultrathin PbTiO3 films by MOCVD

2005 ◽  
Vol 902 ◽  
Author(s):  
Hironori Fujisawa ◽  
Toru Horii ◽  
Yoshiyuki Takashima ◽  
Masaru Shimizu ◽  
Yasutoshi Kotaka ◽  
...  
Keyword(s):  
Ferroelectric Properties ◽  
Piezoresponse Force Microscopy ◽  
Dark Field ◽  
Atomic Scale ◽  
Epitaxial Relationship ◽  
X Ray ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Annular Dark Field

AbstractWe report on microstructure and ferroelectric properties of ultrathin PbTiO3 films epitaxially grown on SrTiO3(100), La-doped SrTiO3(100) and SrRuO3/SrTiO3(100) by MOCVD. High angle annular dark field scanning transmission electron microscopy, atomic force microscopy, x-ray diffraction and x-ray reflectivity measurements demonstrated that 1-20 monolayer (ML)-thick epitaxial PbTiO3 films had high-crystallinity, atomically flat surface and sharp interface at an atomic scale. The epitaxial relationship and thickness were also confirmed by these methods. Kelvin force probe microscopy and contact resonance piezoresponse force microscopy revealed that a 7ML (2.7nm)-thick PbTiO3 film grown on SrRuO3/SrTiO3 had the ferroelectric polarization.

ENHANCED MULTIFERROIC PROPERTIES OF La-DOPED BiFeO3 NANOTUBES FABRICATED THROUGH ANODIC ALUMINA TEMPLATE METHOD

2011 ◽  
Vol 01 (03) ◽  
pp. 325-330 ◽  
Author(s):  
ZHENG-LONG HU ◽  
YAN WANG ◽  
JI-YAN DAI ◽  
DI ZHOU ◽  
YONG-MING HU ◽  
...  
Keyword(s):  
Sol Gel ◽  
Piezoresponse Force Microscopy ◽  
Average Diameter ◽  
Weak Ferromagnetism ◽  
Microscopy Study ◽  
Alumina Template ◽  
Force Microscopy ◽  
Multiferroic Properties ◽  
Nano Crystalline ◽  
20 Nm

Bi0.85La0.15FeO3 (BLFO) nanotubes with an average diameter of about 200 nm and wall thickness of about 20 nm are fabricated by sol–gel alumina template technique, and their room-temperature multiferroic properties are studied. Piezoelectricity and ferroelectricity in the BLFO nanotubes are revealed by piezoresponse force microscopy study of individual nanotube. Doping the BiFeO3 nanotubes with La reduces the crystallization temperature and results in a reduced lose of Bi and therefore improved multiferroic properties of the nanotubes. Enhanced weak ferromagnetism is also observed, and it is attributed to the nano-crystalline structure of the nanotubes.

scholarly journals Effect of octahedron tilt on structure and magnetic properties of bismuth ferrite

2020 ◽  
Author(s):  
Yang Hong ◽  
Jun Li ◽  
Han Bai ◽  
Zhenjia Song ◽  
Ming Wang ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Spin Structure ◽  
Bismuth Ferrite ◽  
Hysteresis Loops ◽  
Rhombohedral Structure ◽  
Raman Analysis ◽  
Natural Resonance ◽  
State Method ◽  
A Site ◽  
Spiral Spin

Abstract Multiferroic trivalent ions doped BiFeO3 ceramics were synthesized using the rapid liquid state method. The trivalent ions (Sm3+, Gd3+, Y3+) doping causes structural distortion without changing the rhombohedral structure. Raman analysis shows that the effect of doping on E modes is greater than A1 modes, and FeO6 octahedron is regulated by ions doping. M-H hysteresis loops show A-site trivalent ions doped samples exhibit improved magnetism compared with pure BiFeO3 since the suppressed spiral spin structure. Doped samples exhibited natural resonance around 16~17 GHz due to the changes in dielectric loss caused by the tilt of the FeO6 octahedron.

Ferroelectric Properties and Domain Clamping of (Bi0.5Na0.5)TiO3 Single Crystals Grown under High-Oxygen-Pressure Atmosphere

2013 ◽  
Vol 566 ◽  
pp. 29-33
Author(s):  
Yuuki Kitanaka ◽  
Hiroaki Onozuka ◽  
Yuji Noguchi ◽  
Masaru Miyayama
Keyword(s):  
Single Crystals ◽  
Oxygen Pressure ◽  
High Performance ◽  
Ferroelectric Properties ◽  
Piezoresponse Force Microscopy ◽  
High Oxygen ◽  
Force Microscopy ◽  
High Oxygen Pressure ◽  
Growth Method ◽  
Measured Polarization

Top-seeded solution growth method under high-oxygen-pressure atmosphere has been developed for obtaining high-performance and large-sized single crystals of ferroelectric (Bi0.5Na0.5)TiO3 (BNT). Crystals grown at 1000 °C at a Po2 of 0.9 MPa exhibited a well-saturated hysteresis with a remanent polarization of 34 μC/cm2 and a coercive field of 22 kV/cm along <100>cubic. The spontaneous polarization of BNT along <111>cubic is estimated to be 59 μC/cm2 from the measured polarization properties along <100>cubic of the crystals obtained. Domain observations using piezoresponse force microscopy revealed that the degraded performance of BNT crystals grown at a low Po2 is attributed to unswitched 71° domains remaining even after applying a high electric field to the crystals .

Nanoscale Ferroelectric Properties of PZN-PT Single Crystals Studied by Scanning Force Microscopy

2003 ◽  
Vol 785 ◽  
Author(s):  
I. K. Bdikin ◽  
V. V. Shvartsman ◽  
A. L. Kholkin
Keyword(s):  
Single Crystals ◽  
Ferroelectric Properties ◽  
Polarization State ◽  
Domain Wall Motion ◽  
Piezoresponse Force Microscopy ◽  
Scanning Force Microscopy ◽  
Switching Behavior ◽  
Zero Field ◽  
Irregular Domain ◽  
Force Microscopy

ABSTRACTHigh-resolution domain studies were performed in Pb(Zn1/3Nb2/3)O3-4.5%PbTiO3 (PZN-PT) single crystals via piezoresponse force microscopy (PFM). Irregular domain patterns with the typical sizes of 20–100 nm were observed on the (001)-oriented surfaces of unpoled samples. On the contrary, (111) crystal cuts exhibited normal micron-sized regular domains with the domain boundaries directed along allowed crystallographic planes. The existence of nanodomains in (100)-oriented crystals was tentatively attributed to the relaxor nature of PZN-PT where small polar clusters were predicted to exist upon zero-field cooling. These nanodomains were considered as the nuclei of the opposite polarization state that ease the switching process for this particular crystal cut. Local piezoelectric hysteresis was also performed by PFM on the nanometer scale. Similar switching behavior of (111)- and (100)-oriented PZN-PT crystals suggests that their superior piezoelectric properties can be related to the domain wall motion rather than to the perovskite lattice itself.

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