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.

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.

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.

Effect of Argon Addition on Nitrogen Containing Carbon Films Prepared by Hot Carbon Filament CVD

1999 ◽  
Vol 593 ◽  
Author(s):  
Yoshihisa Watanabe ◽  
Shinobu Ohnita ◽  
Nobuaki Kitazawa ◽  
Yoshikazu Nakamura
Keyword(s):  
Photoelectron Spectroscopy ◽  
Nitrogen Concentration ◽  
Carbon Films ◽  
Nitrogen Atmosphere ◽  
Carbon Filament ◽  
X Ray ◽  
Force Microscopy ◽  
Carbon And Nitrogen ◽  
Atomic Force ◽  
High Nitrogen Concentration

ABSTRACTNitrogen containing amorphous carbon (a-CNx) films were prepared on silicon single crystal substrates by heating a carbon filament in low pressure nitrogen atmosphere and the effects of argon addition to nitrogen atmosphere were studied by changing the argon fraction under the total pressure of 100 Pa. The growth rate of the films is found to decrease with increasing the argon fraction. x-ray photoelectron spectroscopy shows that the films are composed of carbon and nitrogen and the optimal fraction of argon addition is observed for increasing the nitrogen concentration. Observations by atomic force microscopy reveal that the film surfaces are covered with particle-like features and the size of the features decreases drastically by argon addition. It is concluded that argon addition to the reactant gas is effective in synthesizing a-CNx films with the smooth surface and high nitrogen concentration

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.

scholarly journals Synthesis and Characterization of a Monoclinic Crystalline Phase of Hydroxyapatite by Synchrotron X-ray Powder Diffraction and Piezoresponse Force Microscopy

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 458 ◽  
Author(s):  
Ricardo Pérez-Solis ◽  
José Gervacio-Arciniega ◽  
Boby Joseph ◽  
María Mendoza ◽  
Abel Moreno
Keyword(s):  
Room Temperature ◽  
Monoclinic Phase ◽  
Sol Gel ◽  
Ultrasound Irradiation ◽  
Piezoresponse Force Microscopy ◽  
Medical Rehabilitation ◽  
X Ray ◽  
Force Microscopy ◽  
Piezoelectric Force Microscopy

In this work, we report the synthesis of a monoclinic hydroxyapatite [Ca10(PO4)6(OH)2] (hereafter called HA) prepared by the sol-gel method assisted by ultrasound radiation at room temperature. The characterization of both the monoclinic and the hexagonal phases were performed by powder X-ray diffraction (PXRD) and using synchrotron radiation (SR). The measurement of the piezoelectricity was performed by piezoresponse force microscopy (PFM). The synthesis produced a mixture of monoclinic and hexagonal hydroxyapatite (HA). We also discuss the importance of stabilizing the monoclinic phase at room temperature with ultrasound irradiation. The existence of the monoclinic phase has important advantages in terms of showing piezoelectric properties for applications in the new medical rehabilitation therapies. Rietveld refinement of the PXRD data from SR indicated the monoclinic phase to be of about 81%. Finally, piezoelectric force microscopy was used to distinguish the phases of hydroxyapatite by measuring the average piezoelectric coefficient deff = 10.8 pm/V.

scholarly journals Piezoresponse Force Microscopy: A Window into Electromechanical Behavior at the Nanoscale

MRS Bulletin ◽  
2009 ◽  
Vol 34 (9) ◽  
pp. 648-657 ◽  
Author(s):  
D.A. Bonnell ◽  
S.V. Kalinin ◽  
A.L. Kholkin ◽  
A. Gruverman
Keyword(s):  
Data Storage ◽  
Electromechanical Coupling ◽  
Coupling Effect ◽  
Dynamic Properties ◽  
Piezoresponse Force Microscopy ◽  
Powerful Method ◽  
Force Microscopy ◽  
Ferroelectric Domains ◽  
Local Functional ◽  
Functional Control

AbstractPiezoresponse force microscopy (PFM) is a powerful method widely used for nanoscale studies of the electromechanical coupling effect in various materials systems. Here, we review recent progress in this field that demonstrates great potential of PFM for the investigation of static and dynamic properties of ferroelectric domains, nanofabrication and lithography, local functional control, and structural imaging in a variety of inorganic and organic materials, including piezoelectrics, semiconductors, polymers, biomolecules, and biological systems. Future pathways for PFM application in high-density data storage, nanofabrication, and spectroscopy are discussed.

Ageing Studies of Plasma Deposited Organic Films by Surface Chemical Analysis (ESCA, ToF-SIMS, XAS)

2007 ◽  
Vol 539-543 ◽  
pp. 623-628 ◽  
Author(s):  
Wolfgang E.S. Unger ◽  
Umut Oran ◽  
Sufal Swaraj ◽  
Andreas Lippitz
Keyword(s):  
Chemical Analysis ◽  
Photoelectron Spectroscopy ◽  
Chemical Species ◽  
Organic Films ◽  
Ambient Atmosphere ◽  
Air Exposure ◽  
Practical Applications ◽  
Tof Sims ◽  
Plasma Reactions ◽  
Deposited Films

The formation of plasma-polymerized materials made from organic molecules is a technologically attractive way to obtain films with unique properties for life science applications. Surface properties like bio-compatibility, wettability, etc., can be adjusted by tailoring the chemical functionalization. It is well known that after deposition these films undergo post-plasma reactions, especially when they are exposed to ambient atmosphere. Most often, in applications these films are not used immediately after their deposition – they are usually stored for a certain time. Therefore there is a need for a development of analytical procedures enabling studies of ageing phenomena of plasma chemically deposited films. With the help of these studies a better understanding of basic post-plasma reaction phenomena as well as relevant empiric information for practical applications can be obtained. However, a detailed chemical characterization of plasma chemically deposited films is a great challenge for the analysts because of the co-existence of a number of different chemical species. We investigated r.f. plasma-polymerized organic films by using photoelectron spectroscopy for chemical analysis (ESCA), spectroscopy of the near edge X-ray absorption fine structures (NEXAFS) and time-of-flight secondary ion mass spectroscopy (TOF-SIMS). Ethylene, styrene, allyl alcohol and allyl amine were used as monomers. A dedicated plasma preparation chamber was designed and added to the main analysis chamber of the respective spectrometer. This approach offers the possibility to study plasma-polymerized films in situ and, subsequently, the influence of post-plasma reactions. The important effect of air exposure of the film, in terms of plasma technology denominated as “ageing”, can be studied subsequentially step by step by this unique approach.

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 .

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