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The work was aimed at preparation of green tapes based on a new material Bi_2/3CuTa₄O₁₂, to achieve spontaneously formation of an internal barrier layer capacitor (IBLC), fabrication of multilayer elements using low temperature cofired ceramics (LTCC) technology and their characterization.

The study focused on tape casting, lamination and co-sintering procedures and dielectric properties of Bi_2/3CuTa₄O₁₂ multilayer capacitors. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) studies of the ceramic elements were performed. Impedance spectroscopy was used for characterization of dielectric properties in the frequency range of 0.1 Hz to −2 MHz and in the temperature range from −55 to 400°C. DC conductivity was investigated in the temperature range 20 to 740°C.

SEM observations revealed a good compatibility of the applied commercial Pt paste with the ceramic layers. The EDS microanalysis showed a higher content of oxygen at grain boundaries. The dominant dielectric response, which was recorded in the low frequency range and at temperatures above 0°C, was attributed to grain boundaries. The dielectric response at low temperatures and/or high frequencies was related to grains. The fabricated multilayer capacitors based on Bi_2/3CuTa₄O₁₂ exhibited a high specific capacitance.

A new material Bi_2/3CuTa₄O₁₂ was applied for preparation of green ceramic tapes and utilized for fabrication of multilayer ceramic capacitors using the LTCC technology. This material belongs to the group of high permittivity nonferroelectric compounds with a complex perovskite structure of CaCu₃Ti₄O₁₂, that causes the spontaneously formation of IBLCs.

This paper aims to present the comparative study on the composition, microstructure and dielectric behavior of a group of new nonferroelectric high-permittivity A_2/3CuTa₄O₁₂ (A = Y, Nd, Sm, Gd, Dy or Bi) ceramics.

The materials under investigation were synthesized by solid-state reaction method and sintered at 1,120-1,230°C. Dielectric properties were investigated in the temperature range from −55 to 740°C at frequencies 10 Hz to 2 MHz. Microstructure, elemental composition and phase composition of the ceramics were examined by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) methods. DC conductivity was studied in the temperature range 20-740°C.

XRD analysis revealed peaks corresponding to Cu₂Ta₄O₁₂ along with small amounts of secondary phases based on tantalum oxides. Impedance spectroscopic data and the results of SEM and EDS studies imply the spontaneous formation of internal barrier layer capacitors in the investigated materials. Two steps can be distinguished in the dielectric permittivity versus frequency plots. The low-frequency step of 1,000-100,000 is assigned to grain boundary barrier layer effect, while the high-frequency one of 34-46 is related to intrinsic properties of grains.

Search for new high-permittivity capacitor materials is important for the progress in miniaturization and integration scale of electronic passive components. The paper reports on processing, microstructure, microanalysis studies and dielectric properties of a group of novel nonferroelectric materials with the perovskite structure of CaCu₃Ti₄O₁₂ and the general formula A_2/3CuTa₄O₁₂, being spontaneously formed internal barrier layer capacitors.

The purpose of this study is to prepare a state-of-the-art review on advanced ceramic materials including their fabrication techniques, characteristics, applications and wettability.

This review paper presents the various types of advanced ceramic materials according to their compounding elements, fabrication techniques of advanced ceramic powders as well as their consolidation, their characteristics, applications and wetting properties. Hydrophobic/hydrophilic properties of advanced ceramic materials are described in the paper with their state-of-the-art application areas. Optical properties of fine ceramics with their intrinsic characteristics are also presented within. Special focus is given to the brief description of application-based manipulation of wetting properties of advanced ceramics in the paper.

The study of wetting/hydrophobicity/hydrophilicity of ceramic materials is important by which it can be further modified to achieve the required applications. It also makes some sense that the material should be tested for its wetting properties when it is going to be used in some important applications like biomedical and dental. Also, these advanced ceramics are now often used in the fabrication of filters and membranes to purify liquid/water so the study of wetting characteristics of these materials becomes essential. The optical properties of advanced ceramics are equally making them suitable for many state-of-the-art applications. Dental, medical, imaging and electronics are the few sectors that use advanced ceramics for their optical properties.

This review paper includes various advanced ceramic materials according to their compounding elements, different fabrication techniques of powders and their consolidation, their characteristics, various application area and hydrophobic/hydrophilic properties.

The purpose of this paper is to study the spectral sensitivity characteristics of new pyroelectric sensor based on tetraaminodiphenyl film within the wavelength range of 0.4-10 µm and 300-3,000 µm.

Mylar film with the thickness of about 70 µm was used as the input window. The MDR-41 monochromator-based spectrometric complex and the quasi-optical spectrometer with the set of backward-wave oscillators were used for measurements of the pyrodetector spectral characteristics within the 0.4-10 µm and 300-3,000 µm ranges, respectively.

Mylar was found to have absorption lines within the range of 0.4-10 µm, which must be taken into account when broadband detectors developing. The noise equivalent power in the visible and infrared ranges was less than 6 × 10^–10 W/Hz^1/2, which is about five times lower than for analogue ones. In the sub-THz range, the pyrodetector sensitivity is 2-8 times higher than the Golay cell. The sensitivity of such pyrodetector weakly depends on the wavelength in the total measured range.

The pyroelectric sensor has good prospects for use in super wide spectral range, from ultraviolet to millimeter radiation, in spectrometers for scientific research, in industry for the operational control of THz radiation sources, as well as in security THz-systems.

The spectral sensitivity characteristics of the pyroelectric photosensor based on TADPh in the visible, infrared and terahertz ranges were measured. The prospects for the use of such sensors were determined.

Both the current long term telecommunication trends toward optical networking and the recent growth in information bandwidth have pushed the necessity for improved optical communications. Our fabrication approach, which leverages our expertise in solid freeform fabrication in conjunction with sol‐gel technology, has advantages over these other methods because of the inherent benefits of using a direct‐write philosophy, such as design flexibility and minimal post‐processing. However, fabrication of such novel optical components requires extensive knowledge of their light guidance capabilities. This paper shows the technical issues involved in both modeling and characterizing small optical components fabricated by locally densifying sol‐gels in a modified direct‐write process.

The ability to see in the dark is a key differentiator in many military scenarios and the development of thermal imaging (TI) systems has provided the military with a battle winning capability. One of the current key thrusts is to be able to detect and identify targets at significantly longer ranges. The research programme in QinetiQ has been providing solutions to satisfy these requirements for many years. In addition, one of the major benefits from this research, has been the opportunity to provide TI sensors into the civil market for application including fire fighting. In this review many of the new concepts currently being developed are described and illustrated.

A new lass of sensors for thermal imaging and detection in the infra‐red band is emerging which exploits the pyroelectric effect in ferroelectric materials. These sensors, which are fabricated in the form of large linear or two‐dimensional arrays of detectors interfaced to a silicon readout circuit, do not require cooling for their operation, in contrast to the photon detection based thermal imagers. They thus have the potential for low cost thermal detection and imaging. This paper examines the design of these arrays and the technologies employed in their fabrication, with particular attention to their specialised packaging requirements, by reference to a range of linear and two‐dimensional pyroelectric array devices that have been fabricated in this laboratory.

Looks at the use of infrared sensors, noting that they fall into the two basic groups of quantum and thermal devices. Focuses on quantum devices and their further subdivision into photoconductive and photovoltaic types. Notes that thermal devices also fall into two categories: those relying on the Seebeck effect, and those known as ferroelectrics. Looks at the use of ferroelectric materials in pyrometry. Concludes by noting the advantages of some of the various types of system.

Despite many advances during the last decade in both infra‐red sensor and solid state camera technology, until now little headway has been made in the production of cost‐effective semiconductor sensor arrays capable of operating far into the infra‐red. Old ideas, renewed by the capabilities offered by the latest micromachine technology, may change all this. Reviews the problems associated with building such sensor arrays before introducing some interesting new research results.