Characterization and Dielectric Properties of Microwave Rare Earth Ceramics Materials for Telecommunications

The rare-earth-metal-oxide based electronic materials were produced via a conventional mixed-oxide route. Thermal analysis, XRD and SEM were used to follow phase evolution and demonstrate the phase purity. Analytical TEM were used to analyze crystal structural defects and to track the presence of secondary phases, especially at grain boundaries. A crystal structure determination was also performed. Phonon modes were analyzed with FTIR and Raman spectroscopies and correlated with the origin of dielectric permittivity ({\epsilon}r) and radiation losses (tan {\delta}) characteristics. In some compound and mixed compound Raman band mode exist, but this band is absent in simple perovskite indicating that this band is associated with distribution of B-site cations ordering. Some of compound shows long range order in B-site, while it does not present in other material. A photo-acoustic sampling technique in conjunction with the FTIR spectroscopy was employed, allowing the analysis of neat materials with minimal sample preparation. Measurements of the quality factor (Qf), {\epsilon}r and the temperature coefficient of the resonant frequency ({\tau}f) characteristics were made at the microwave resonant frequency using a vector or network analyzer. These perovskite have low tolerance factor because of considerable size misfit of constituting atoms. For determination of atomic size and characterization of constitution atoms, the test of samples and Rietveld refinement using GSAS programs were used to do this examination. These materials have attractive dielectric properties are being evaluated extensively for substrates for multi-chip-module (MCM) devices and microwave telecommunications.Comment: Dissertatio

Fractal analysis and ferroelectric properties of Nd(Zn-1/Ti-2(1)/(2))O-3(NZT)

The challenges in productivity of satellite mobile devices are growing rapidly to overcome the question of miniaturization. The intention is to supply the electrical and microwave properties of materials by discovering their outstanding electronic properties. Neodymium Zinc Titanate (NZT) can be a promising ferroelectric material due to its stable dielectric and microwave properties. The grain size and shape of NZT have a strong influence on overall material performances. Therefore, shape, reconstruction and property of the coming compound take an important part and can be predicted before being utilized in the devices. The significant of this research is to define ferroelectric properties of NZT and to characterize it by using Fractal Nature Analysis (FNA). FNA is a powerful mathematical technique that could be applied to improve the grain shape and interface reconstruction. The fractal structure is identified by its self-similarity. The self-similarity of an object means a repetition of shapes in smaller scales. A measure of this structure is computed using the Hausdorff dimension. It is for the first time in this investigation the Fractal analysis method is applied for the microwave materials microstructure reconstruction which makes this research an innovative work and will open the door for Curie-Weiss law fractal correction. In connection to our previous research for dielectric properties fractalization, we had some characterization and reconstruction data which include the Hausdorff dimension (HD).info:eu-repo/semantics/publishedVersio

Extracting the innovation policies for Iran based on the approximation of policy implications for comparative economic doctrines

Due to many differences in presumptions and theoretical foundations within neoclassical and evolutionary economics, policy-makers are always confronted with the dilemma of selecting one of these two central models for technology and innovation policy. In light of widely institutionalised ineffectiveness in the field of market and systematic coordination – in Iran as well many other countries – the present investigation presumes that reliance on any of the above doctrines alone is ineffective. An intermediate concept of policy rationales to achieve a comparative structure of policy implications is proposed. Policy rationales (in innovation and technological policy) for neoclassical and evolutionary economics were derived based on a thematic analysis. A spectrum of policy implications of both doctrines was designed and completed in the form of a questionnaire for, together with theoretical foundations and policy rationales by specialists of the field of innovative and technological policy in Iran. Given the institutional conditions and structural frameworks which actually exist, and in spite of wide dissimilarities within the theoretical foundations of neoclassical and evolutionary economics, Clustering of respondents and subsequent test trials show that policy implications of the economics doctrines in the field of innovative and technological policy in Iran are complementary and convergent

The Rare earth Neodymium Zinc Titanite properties in microwave telecommunications and fractal nature structure analysis

In this paper we present the research results on dielectric properties based on Rare earth Neodymium Zinc Titanites (NZT). These results show that we have a stable perovskite structure and the other structure search suggest that the monoclinic crystal structure could be proposed for NZT. Modelling and simulation were used in this research to define the atomic position and crystal structure of NZT. The compositions have very specific dielectric properties which could useful in microwave telecommunications. It is very important to reduce the size, weight and microelectronic devices coast for future applications. So, the new miniaturization, better packaging and higher level of integrations, by using multi-layer processes and advanced interconnection methods are very important for modern telecommunications. In that sense, some new results and knowledges about fractal nature in materials, electronic ceramics and perovskites are very important for new fractal microelectronics applications for modern communications and IT technologies. Instead of classic semiconductor technologies, which are not anymore so much perspective and promising in this area. Finally, all of these aspects are very important for microanthena systems in telecommunications

Structural and Dielectric Properties of Rare earth Neodymium Zinc Titanite

Using the high -resolution x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and temperature-dependent microwave resonator characterization the dielectric properties and phase assemblage of Rare earth Neodymium Zinc Titanite (NZT) was investigated in this research work. NZT ceramics samples were prepared via mixed oxide. The result shows that it is distrustful to be a stable perovskite structure, in fact something comparable to Ilmenite structure, nevertheless further research shows that the monoclinic structure can be purposed for NZT. The Modelling and simulation were used in this study to define the atomic position and structure of NZT. In conclusions, single-phase ceramics of NZT; have been synthesised at every sintering temperature 1250-1675°C. NZT has the temperature coefficient of resonant frequency 47 MK-1, Quality factor was 42000 at frequency of 4.33 GHz and relative permittivity 36. The crystal structure of NZT is monoclinic with Bravais Lattice P and space group of P21/n. Kikuchi line shows that this material has a single phase. These compositions have promising dielectric properties and can be used in microwave telecommunications

Internal mechanics of anti stick–slip tool

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Application of Nd (Mg½Ti ½) O3 (NMT) Perovskite in Mobile Communications

The electrical conductivity, phase, and space group of property of the NMT substance and grain boundary of samples were approximated from complex compound by Raman spectroscopy, X-ray, SEM, TEM, and differential scanning calorimeter (DSC), samples prepared and analyzed in the laboratory in the frequency ranges from 9.76 GHz. The solid-state conventional method utilized. All the samples were tested by using XRD from 1250°C to 1550°C by increasing 50 degrees for every sample and cooling to the room temperature. The contraction of structure did not happen even at elevated temperature. The increase in Nd+ ion polarizability is 0.50 nm compared to La+ rare elements material, which is 0.60, this contributes to change of perovskite cubic. This is result of the smaller size of Nd+ 0.127 nm cation compared to La+ which increase number of dipoles despite the reduction of diploes and expands relative permittivity (εr). The single-phase material produced which shows quality factor Q×f = 60000 saturated at 10 GHz and temperature coefficient of (τf) = -77 MK-1.acceptedVersionPeer reviewe

Magnetic materials, Curie-Weiss law and fractal correction

Neodymium zinc titanate (NZT) is a very attractive perovskite due to its magnetic and dielectric properties. Considering the microstructure influence NZT stability and performance, it is of great importance to establish an approach for the analysis and prediction of grain boundary phenomena. The fractal nature analysis has already proved to be valuable for the reconstruction and prediction of ceramics intergranular electrical properties. However, no researches were performed on the fractal analysis applied on magnetic materials. This method could give an insight in magnetic properties change from the bulk to the grain interface level. In this study, fractal analysis was applied for the Curie-Weiss law correction, introducing fractal correction into magnetic materials for the first time. NZT powders used in this research for fractal analysis were obtained after sintering at different temperatures in the range from 1450°C to 1675°C.Connection between the microstructure fractal nature and the resulting magnetic permeability has been established, enabling the application on different magnetic materials in the future. This creates a foundation for new researches that will lead to further miniaturization of satellite and mobile devices