To produce controlled radio frequency and microwave devices such as phased antenna arrays, delay lines, an affordable and inexpensive way of manufacturing varactors in large quantities should be found. One of the promising ways to produce such varactors is based on the use of a BST-paste with a low firing temperature, which allows it to be integrated into a substrate of low-temperature co-fired ceramics (LTCC).

Keywords: semiconductor, ferroelectric, BST-paste, ferroelectric condenser, LTCC technology

Piezoceramics phases of (1-х)PbTiO3-xPbZrO3 is the basis of most high-performance piezoelectric materials. Electrophysical and mechanical properties of these materials can be varied over a wide range by varying the composition and by processing methods: the methods and modes of sintering conditions polarization. Topical to study the influence on the properties of PZT materials processing methods at the stages of manufacturing piezoelectric samples. In the role model of the object has been selected multicomponent system PbTiO3-PbZrO3-PbNb2/3Zn1/3O3-PbW1/2Mg1/2O3-PbSb2/3Mn1/3O3. Samples of piezoelectric elements for the study were obtained in two ways: in the first case, the sintering samples was carried out by the usual ceramic technology, and in the second by hot pressing. The grain structure was formed in both cases in the presence of the glass phase, the quantity of which decreases with increasing temperature, while in the first case, an increase in the velocity of the secondary recrystallization, and in the second of its suppression. It was found that regardless of the technology of the samples εT33/ε0, d33 and VЕ1 at high temperatures, due to the increase of grain and coercive field, which complicates the process of polarization. Maximum values εT33/ε0, d33 and VЕ1 samples prepared by hot pressing at 10 - 15% higher than if received by conventional ceramic technology.

Keywords: Piezoelectric ceramics, doping, combination, pezophase, piezomaterial

The combination of the unique, abnormal properties shown by oxidic systems with structure of spinel on the basis of transitional elements chromites draws attention of researchers for many years. Some systems on the basis of transitional elements chromites (for example, nickel and copper chromites) have critical elements (multicritical points, lines of phase transitions of the second sort, etc.) on the phase chart. Near these elements of the phase chart materials possess unique chemical and physical properties. Therefore development methods of receiving and research of phase forming and properties in NIO-CoO-CuO-Cr2O3 system represent fundamental and practical interest for chemistry and technology of inorganic substances. In this work processes of spinel structure formation in system 0,6 NiCr2O4 – 0,2 CoCr2O4 – 0,2 CuCr2O4 from crystal chemistry positions are considered. Formation of two solid solutions on the basis of nickel (II) chromite – with structure of cubic spinel and with tetragonal distorted structure is established. The influence of cooperative Yahn-Teller effect on processes of a spinel forming and on stabilizing impact of chloride of potassium on process of education of  two spinel solid solutions is suggested. Influence of a power factor of cation stabilization in knots of a crystal lattice as one of the important factor in reaction of spinel structure formation is considered.

Keywords: spinels, chromites of transitional elements, Jahn-Teller effect

The problem of manufacturing technology heterostructures pezofaza - metal considered in the article. Complexity consists in the fact that during the removal of the polymer in the system at low temperatures are formed porous layers, formed powders separated metal layers, having island macrostructure. One way to solve the problem - reducing the firing temperature heterostructures. Proposed to decrease the sintering temperature by using of functionally active glass-phases. Reducing the sintering temperature of products also allows to replace platinum electrodes inexpensive silver-based alloys. Obtained by solid state reaction method of piezoceramic material has a low sintering temperature (980 ° C) and high electrical parameters. Found that not only the proportion of the vitreous mass, but also their qualitative influence on the properties of piezomaterials    

Keywords: heterostructure glass phase, the sintering temperature, porosity, ferroelectric phase

Piezoelectric ceramics on the basis of the phase of (1-x) PbTiO3-xPbZrO3 is the basis of most high-performance piezoelectric materials. Electrophysical and mechanical properties of these materials can vary widely in different ways. Traditional methods include changes in composition within the morphotropic region and doping. Now is the study of the influence of topical makrolegirovaniya the material properties of the PZT system. As a model system was selected phase of the PZT system, the compositions of which MO belong, one of which contains a dopant in the sublattice (A) and another - in the sublattice dopants (B). The studies established that one of the effective ways of varying the parameters piezomaterials may be the formation of solid solutions on the basis of two or more piezoelectric phases having different combinations of electrical parameters  

Keywords: Piezoelectric ceramics, doping, kombinorovanie, pezofaza, piezo

Information about authors of issue №2 (2013)

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  Influence of a method of manufacture of porous ceramic frames on the basis of system Lead zirconate titanate (PZT) on their microstructure is set. It is shown that when using a method of formation of the frame based on deleting a porophore, the microstructure of a target product depends as by nature a steam generator, and the sizes of particles of a porophore and piezo-phase. Frames with preferentially open nature of porosity create porophore systems decaying or being sublimed in case of temperature increase.  If the porophore to its thermal destruction or evaporation melts, the ceramic frame will have, preferentially, closed nature of porosity. Within the second of probed methods of porous frames creation based on expansion of an amorphous phase, synthesized within a method volume «chemical construction», samples with diameter of pores from 70-90 nanometers to 450-500 nanometers and the mixed nature of porosity are received.

Keywords: ceramic frames, piezoelectric phases lead zirconate-titanate (PZT), piezoelectric composites with connection 3 - 3 and 3 – 0

It was investigated the influence several additives and process parameters on the properties of piezoelectric ceramics based on PZT phase systems. It was shown that the use of the substitution of Pb2+ ions on the Bi3+, and Ti4+ ions, and Zr4+ to Fe3+ and Mn4+, as well as the method of "chemical assembly «allows to obtain increase the Curie temperature of ceramic samples of 50 - 170°C. The theoretical aspects of this area of research have been discussed in this article.

Keywords: ferroelectric phase, Curie temperature, ceramics, precursors, perovskite, a solid-state method, a method of «chemical assemblage

Information about authors of issue №3 (2012)

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Information about authors of issue №2 (2012)

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Information about authors of issue №1 (2011)

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Information about authors of issue №3 (2010)

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