Room temperature surface piezoelectricity in SrTiO3 ceramics via piezoresponse force microscopy

Research on synthesis, characterization and determination of processing — structure — property relationships of commercially important ferroelectric thin films has been performed. The sol–gel type solution deposition technique was applied to produce good quality thin films of [Formula: see text][Formula: see text]TiO3 (BST60/40) chemical composition on the stainless steel substrates. The thin films were characterized in terms of their microstructure, crystal structure, phase composition, piezoelectric and dielectric properties. It was found that the BST60/40 thin film adopted the cubic structure at room temperature with an elementary cell parameter [Formula: see text] Å. Morphology of the thin film surface was studied with Atomic Force Microscopy (AFM). Average roughness of the thin films surface was found ([Formula: see text]m). Piezoresponse Force Microscopy (PFM) was applied for the thin film characterization. Active piezoelectric regions were found in BST60/40 thin film. Therefore, dielectric response measured at room temperature was studied in assumption of piezoelectric electric equivalent circuit.

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

Crystals ◽

10.3390/cryst8120458 ◽

2018 ◽

Vol 8 (12) ◽

pp. 458 ◽

Cited By ~ 2

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.

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Influence of Metastable States on Electrophysical Properties in Ferroelectric Crystalline Polymers

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.605.499 ◽

2014 ◽

Vol 605 ◽

pp. 499-502

Author(s):

V.V. Kochervinskii ◽

A. Pavlov ◽

N. Kozlova ◽

N. Shmakova ◽

D.A. Kiselev ◽

...

Keyword(s):

Room Temperature ◽

Piezoresponse Force Microscopy ◽

Electrophysical Properties ◽

Slow Evaporation ◽

Force Microscopy ◽

Crystalline Polymers ◽

Copolymer Films ◽

Conformation Changes ◽

Ferroelectric Domains ◽

Microscopy Method

The poling and local piezoresponse mechanism has been investigated in ferroelectric polymers. Isotropic 94/6 composition vinylidenefluoride and tetraflouroethylene copolymer films is formed from acetone at room temperature by slow evaporation of solvent. The copolymer crystallization results in metastability (nonequilibre) form at high overcooling temperatures. IR spectroscopy shows occurrence of isomers with conformation TGTG-, T3GT3G-and (TT)n. The local piezoresponse shows that ferroelectric domains include crystals areas as well as nonordered phase. After annealing by heating to 150 oC was found conformation changes in polymer chain: T3GT3G-TGTG-and T3GT3G-(TT)n. It is show that the regular conformation chains length rising after annealing. Polarization value decreasing kinetic was investigated by piezoresponse force microscopy method.

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Ferroelectric-Relaxor Behavior of Highly Epitaxial Barium Zirconium Titanate Thin Films

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.34.67 ◽

2015 ◽

Vol 34 ◽

pp. 67-72

Author(s):

Madhuparna Pal ◽

Ming Liu ◽

Chun Rui Ma ◽

Chong Lin Chen ◽

R. Guo ◽

...

Keyword(s):

Thin Film ◽

Room Temperature ◽

Piezoresponse Force Microscopy ◽

Relaxor Behavior ◽

Zirconium Titanate ◽

Film Sample ◽

Ferroelectric Relaxor ◽

Force Microscopy ◽

Barium Zirconium Titanate ◽

Ferroelectric Switching

Ferroelectric-relaxor behavior on highly epitaxial Barium Zirconium Titanate (Ba (Zr0.2Ti0.8)O3) thin film was investigated using the Piezoresponse Force Microscopy specifically to investigate the onset of relaxor behavior. The surface roughness, microstructure and the grain size of the film were systematically studied. Ferroelectric switching at random localized points were observed at room temperature though it has been previously reported that the phase transition in BZT-20 occurs at 285K. Phase reversal with the reversal of the applied voltage was also seen. Scanning Capacitance Microscope has been employed to interrogate the localized change in the capacitance with change in voltage. The thin film sample showed the presence of ferroelectric nanoregions at room temperature unlike its bulk counterparts which is paraelectric at room temperature.

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Piezoresponse force microscopy behaviour of Bi4Ti3O12 ceramics with various excess bismuth

Processing and Application of Ceramics ◽

10.2298/pac1101001a ◽

2011 ◽

Vol 5 (1) ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

Ederson Aguiar ◽

Alexandre Simões ◽

Francisco Moura ◽

Mario Cilense ◽

Elson Longo ◽

...

Keyword(s):

Room Temperature ◽

Oxygen Vacancies ◽

Single Phase ◽

Bismuth Titanate ◽

Piezoresponse Force Microscopy ◽

Orthorhombic Structure ◽

Precursor Method ◽

Raman Analysis ◽

Force Microscopy ◽

Vibrational Bands

Bismuth titanate (Bi4Ti3O12 - BIT) ceramics derived from different amounts of excess Bi2O3 were prepared using the polymeric precursor method. In spite of excess bismuth, single phase ceramics were obtained with a con?trolled microstructure. Raman analysis evidenced typical vibrational bands of the BIT phase. UV-vis spectra indicated that excess Bi2O3 causes a reduction in defects in the BIT lattice due to the suppression of oxygen vacancies located at the octahedral BO6-ion. The microstructure and electrical properties are strongly depen?dent on the excess Bi2O3. Appropriate initial Bi2O3 excess reduces the leakage current and loss tangent and thereby improves the polarization of BIT ceramics. Rietveld analyses confirmed that the powders crystallize in an orthorhombic structure with a space group of Fmmm at room temperature. The polarization reversal was investigated by applying ac voltage through a conductive tip during the area scanning and was investigated by piezoresponse force microscopy (PFM).

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Cryogenic atomic force microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084570 ◽

1991 ◽

Vol 49 ◽

pp. 54-55

Author(s):

K. A. Fisher ◽

M. G. L. Gustafsson ◽

M. B. Shattuck ◽

J. Clarke

Keyword(s):

Room Temperature ◽

Rapid Freezing ◽

Cryogenic Temperatures ◽

Soft Or ◽

Electrically Conductive ◽

Force Microscopy ◽

Flexible Molecules ◽

Advantages And Disadvantages ◽

Atomic Force ◽

Chemical Perturbation

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).

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Local ferroelectric polarization switching driven by nanoscale distortions in thermoelectric $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$

Scientific Reports ◽

10.1038/s41598-021-96299-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Aastha Vasdev ◽

Moinak Dutta ◽

Shivam Mishra ◽

Veerpal Kaur ◽

Harleen Kaur ◽

...

Keyword(s):

Thermal Conductivity ◽

Figure Of Merit ◽

Room Temperature ◽

Lattice Thermal Conductivity ◽

Direct Evidence ◽

Temperature Dependent ◽

Force Microscopy ◽

Ferroelectric Domains ◽

Pdf Analysis ◽

Ferroelectric Transition Temperature

AbstractA remarkable decrease in the lattice thermal conductivity and enhancement of thermoelectric figure of merit were recently observed in rock-salt cubic SnTe, when doped with germanium (Ge). Primarily, based on theoretical analysis, the decrease in lattice thermal conductivity was attributed to local ferroelectric fluctuations induced softening of the optical phonons which may strongly scatter the heat carrying acoustic phonons. Although the previous structural analysis indicated that the local ferroelectric transition temperature would be near room temperature in $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$ Sn 0.7 Ge 0.3 Te , a direct evidence of local ferroelectricity remained elusive. Here we report a direct evidence of local nanoscale ferroelectric domains and their switching in $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$ Sn 0.7 Ge 0.3 Te using piezoeresponse force microscopy(PFM) and switching spectroscopy over a range of temperatures near the room temperature. From temperature dependent (250–300 K) synchrotron X-ray pair distribution function (PDF) analysis, we show the presence of local off-centering distortion of Ge along the rhombohedral direction in global cubic $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$ Sn 0.7 Ge 0.3 Te . The length scale of the $${\text {Ge}}^{2+}$$ Ge 2 + off-centering is 0.25–0.10 Å near the room temperatures (250–300 K). This local emphatic behaviour of cation is the cause for the observed local ferroelectric instability, thereby low lattice thermal conductivity in $${\text {Sn}}_{0.7}{\text {Ge}}_{0.3}{\text {Te}}$$ Sn 0.7 Ge 0.3 Te .

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