Modulation of the Physical Properties of Lead Zirconate by the Stress‐Induced Structural Defects

Author(s):  
Marina Sirota ◽  
Kamaludin Abdulvakhidov ◽  
Tatiana Lastovina ◽  
Anna Pnevskaya ◽  
Elza Ubushaeva ◽  
...  
Author(s):  
K.P.D. Lagerlof

Although most materials contain more than one phase, and thus are multiphase materials, the definition of composite materials is commonly used to describe those materials containing more than one phase deliberately added to obtain certain desired physical properties. Composite materials are often classified according to their application, i.e. structural composites and electronic composites, but may also be classified according to the type of compounds making up the composite, i.e. metal/ceramic, ceramic/ceramie and metal/semiconductor composites. For structural composites it is also common to refer to the type of structural reinforcement; whisker-reinforced, fiber-reinforced, or particulate reinforced composites [1-4].For all types of composite materials, it is of fundamental importance to understand the relationship between the microstructure and the observed physical properties, and it is therefore vital to properly characterize the microstructure. The interfaces separating the different phases comprising the composite are of particular interest to understand. In structural composites the interface is often the weakest part, where fracture will nucleate, and in electronic composites structural defects at or near the interface will affect the critical electronic properties.


2016 ◽  
Vol 51 (16) ◽  
pp. 2263-2276 ◽  
Author(s):  
Jafar Rezania ◽  
Hamid Rahimi

Carbon compounds have high dielectric losses, which means that these materials are heated efficiently by microwave irradiation. Carbon materials can be used as microwave absorbers in polymeric materials that are transparent to microwave irradiation. In this paper, carbon-reinforced polypropylene composites were exposed to microwave irradiation and then their dynamic mechanical thermal properties, electromagnetic shielding, and surface morphology were investigated. The test results showed that mechanical and physical properties of carbon–polypropylene composites improved following microwave exposure. The dynamic mechanical thermal analysis results showed that their storage and loss modulus were improved following microwave treatment. It is postulated that microwave irradiation heats carbon materials, which is likely to melt neighboring matrix thus improving interfacial adhesion and structural defects.


Author(s):  
Д.А. Филиппов ◽  
В.М. Лалетин ◽  
Н.Н. Поддубная ◽  
V.V. Shvartsman ◽  
D.C. Lupascu ◽  
...  

A new way for determining the magnetostriction characteristics of a composite multiferroics using the magnetoelectric response of the structure is proposed. It is shown that integral from the field dependency of linear magnetoelectric coefficient is the magnetostriction characteristic of the structure. The results of an experimental study of the physical properties of bulk composites based on lead zirconate titanate and ferrite-nickel spinel are presented. Based on the field dependence of the magnetoelectric voltage coefficient, magnetostriction curves of composite structures with a content of ferrospinel of 10–70% were obtained.


2017 ◽  
Vol 18 (2) ◽  
pp. 206-210
Author(s):  
N. I. Domantsevych ◽  
O. V. Shunkina ◽  
B. P. Yatsyshyn

The changes in structure and physical properties of polymeric materials that exploited in a long time with complex mechanical loads used in pipe systems for high-pressure cold water have been studied. A significant reduction in the mechanical properties of polymeric materials has been established. The most typical structural defects that occur in polymer materials during manufacture and in the exploitations, using electron microscopic studies identified.


Author(s):  
Sugato Hajra ◽  
Sushrisangita Sahoo ◽  
Pravat Kumar Rout ◽  
RNP Choudhary

Purpose of Study: The present work shows studies of some physical properties of a gallium (Ga) modified lead zirconate titanate (PbZrTi)O3 with molar ratio Zr/Ti::48/52 (i.e., near morphotropic phase boundary (MPB)) having (Pb0.92Ga0.08)(Zr0.48Ti0.52)0.98O3 (PGaZT-8) as a chemical composition. Methodology: The material was fabricated employing high-temperature mixed oxide route. Main Finding: X-ray diffraction spectra suggest a distorted perovskite structure having two phases (tetragonal and monoclinic phases) with the substitution of small amount (2 and 4 wt %) of Ga in Pb(ZrTi)O3 (PZT). However, with higher concentration of Ga (6 and 8 wt %) in PZT, the multiphase perovskite structure is converted into an orthorhombic system with few impurity phase of Ti3O5. Analysis of field emission scanning electron micrograph (FESEM) of 8 wt% Ga modified PZT (PGaZT-8) shows the uniform distribution but different dimension and shape of grains depicting high-density ceramic sample. In the dielectric studies no dielectric anomaly exists in the experimental temperature range (25-500oC) in PGaZT-8, which determines the substitution of 8 wt% Ga in PZT (in MPB region) is found responsible for the suppression or shift (towards higher temperature) of known ferroelectric phase transition of PZT. There is an enhancement of permittivity, loss factor and conductivity as Pb site of PZT is doped with Ga. Applications of study: This study is useful for the determination of the characteristics of the prepared material as a base for device fabrication. Novelty of the Study: It is a systematic study of correlation of structural properties with the physical properties. It helps to understand the relaxation and conduction mechanism of PGaZT-8 using impedance and modulus spectroscopy.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shingo Toyoda ◽  
Manfred Fiebig ◽  
Lea Forster ◽  
Taka-hisa Arima ◽  
Yoshinori Tokura ◽  
...  

AbstractLocal and low-dimensional structures, such as interfaces, domain walls and structural defects, may exhibit physical properties different from the bulk. Therein, a wide variety of local phases were discovered including conductive interfaces, sheet superconductivity, and magnetoelectric domain walls. The confinement of combined magnetic and electric orders to spatially selected regions may be particularly relevant for future technological applications because it may serve as basis of electrically controllable magnetic memory devices. However, direct observation of magnetoelectric low-dimensional structures cannot readily be done partly because of the lack of experimental techniques locally probing their physical nature. Here, we report an observation of multiferroic ribbon-like domains in a non-multiferroic environment in MnWO4. Using optical second harmonic generation imaging, we reveal that a multiferroic phase is stabilized by locally generated strain while the bulk magnetic structure is non-multiferroic. We further find that the confined multiferroic state retains domains with different directions of electric polarization and we demonstrate deterministic writing of a multiferroic state embedded in a non-multiferroic environment.


2009 ◽  
Vol 51 (7) ◽  
pp. 1524-1526 ◽  
Author(s):  
S. N. Kallaev ◽  
Z. M. Omarov ◽  
A. R. Bilalov ◽  
M. Kh. Rabadanov ◽  
S. A. Sadykov ◽  
...  

1980 ◽  
Vol 49 (1) ◽  
pp. 67-70 ◽  
Author(s):  
S.I. Radautsan ◽  
V.E. Tezlevan ◽  
K.G. Nikiforov

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