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Artificial neural networks (ANNs) are basically the structures that perform input–output mapping. This mapping mimics the signal processing in biological neural networks. The basic element of biological neural network is a neuron. Neurons receive input signals from other neurons or the environment, process them, and generate their output which represents the input to another neuron of the network. Neurons can change their sensitivity to input signals. Each neuron has a simple rule to process an input signal. Biological neural networks have the property that signals are processed through many parallel connections (massively parallel processing). The activity of all neurons in these parallel connections is summed and represents the output of the whole network. The main feature of biological neural networks is that changes in the sensitivity of the neurons lead to changes in the operation of the entire network. This is called adaptation and is correlated with the learning process of living organisms. In this paper, a set of artificial neural networks are used for classifying the human skin biophysical impedance data.

Data on thermally induced transformations of Mn exchanged zeolites LTA and FAU topology are presented in this paper. Thermally induced phase transformation of Mn-exchange zeolites are followed in the range from 700 to 1300?C. Both frameworks collapse into amorphous intermediate products after heating between 600 and 650?C. Prolonged heating of the intermediate product above 1100?C results directly in formation of a disorder Mn-anorthiteLTA and Mn-anorthiteFAU. The parameter of unit cell of Mn-anorthiteLTA and Mn-anorthiteFAU, in temperature range between 700 and 1300?C, was observed in space group C-1. The phase conversions in the temperature range investigated were followed by thermal, X-ray powder diffraction and FT-IR analyses

This paper is based on fundamental research to develop the interface structure around the grains and to control the layers between two grains, as a prospective media for high-level electronic parameters integrations. We performed the experiments based on nano-BaTiO3 powders with Y additives. All results on dielectric parameters on submicron level are the part of global values the same measured characteristics at the bulk samples. The original idea is to develop the new computing ways to network electronic parameters in thin layers between the grains on the way to get and to compare the values on the samples. Artificial neural networks are computing tools that map input-output data and could be applied on ceramic electronic parameters. These are developed in the manner signals are processed in biological neural networks. The signals are processed by using elements which represent artificial neurons, which have a simple function to process input signal, as well as adjustable parameter which has an influence to change output signal. The total network output presents the sum of a large number neurons outputs. This important research idea is to connect analysis results and neural networks. There is a great interest to connect all of these microcapacitances by neural network with the goal to compare the results in the standard bulk samples measurements frame and microelectronics parameters. The final result of the study was functional relation definition between consolidation parameters, voltage (U) and relative capacitance change, from the level of the bulk sample down to the grains boundaries.

The effect of Nb on the microstructure and dielectric properties of BaTiO3 ceramics was investigated. The Nb/Mn–BaTiO3 ceramics were prepared using a conventional solid-state method. The concentration of Nb varied from 0.1 to 5.0 at% but Mn was fixed at 0.05 at%. The SEM indicated that compositions of 0.1 and 0.5 at% Nb displayed a fairly uniform microstructure and homogeneous distribution of additives, with a grain size of less than 2 μm. In highly doped samples a wide range of microstructural features was observed, from homogeneous and completely fine-grained microstructure to the appearance of secondary abnormal grains with core-shell structure. The dielectric constant and the loss tangent of modified ceramics were measured as a function of temperature (20–180 °C) and frequency (100 Hz-1MHz) for different concentrations of additives. The obtained results have shown that the dielectric constant at, both, room temperature (er) and Curie temperature (ermax), decreased as the concentration of Nb5+ increased. Thus, the highest values for the dielectric constant at room temperature (er = 6648) as well as at Curie temperature (ermax = 7680) were measured for the 0.1Nb/Mn–BaTiO3 samples sintered at 1350 °C. The highly doped BaTiO3 ceramics were found to exhibit lower values of the dielectric constant and low dielectric losses at room temperature. In these samples, stable dielectric permittivity with a flat dielectric behavior over a wide temperature range is observed. The Curie constant for all series of samples decreases with an increase of dopant concentration and the highest values were measured from samples doped with 0.1 at% Nb. The effect of additives on the Curie constant change is more pronounced at higher sintering temperatures. The analysis of the critical nonlinearity exponent (γ = 1.07–1.27), for lower dopant concentrations, shows a sharp phase transformation. For samples with increased Nb content, the degree of nonlinearity γ is higher indicating a diffuse phase transformation.

Due to the increased use of yttrium in agriculture and industry, there is a growing interest in the impact of yttrium on the environment and human health. Developing novel procedures to detect and quantify species of yttrium represents an important task. In this work, we apply laser desorption/ionization-mass spectrometry (LDI-MS) to detect cluster ions of the solution of yttrium(III) chloride (YCl3) at different pH values. The density functional theory (DFT) calculations were used to reveal the energetically most favored structures of the anions and cations chosen from the LDI-MS results. Examination of the positive and negative mode LDI mass spectra of YCl3 showed the presence of the heterogeneous mononuclear and polynuclear clusters, such as [YCl(OH) (H2O)3][Formula: see text], [Y2(H2O)][Formula: see text], [Y4H2(H2O)4][Formula: see text], and [Y5O4H3][Formula: see text] (at pH 2 and 5) and [Y2Cl2(H2O)2][Formula: see text], [Y2O5(HCl)(OH)][Formula: see text], and [Y3OH3(OH)2(H2O)][Formula: see text] (at pH 2, 5, and 10). The variation in the pH solution of YCl3 slightly affects the LDI mass spectrum of these yttrium clusters. It has only been noticed that the [Y4H2(H2O)4][Formula: see text] cluster ions were not detected at pH 10. These results can become a guide in the detection of yttrium chloride by LDI-MS in real samples in different fields (ecological, food, and human).

The electronic packaging and systems are very important topics as the limitation of miniaturization approaches in semiconductor industry. Regarding the optimal materials microstructure for these applications, we studied different alloys such as Sn-3.0Ag-0.5Cu (wt.%)/organic solderability preservative (SAC305/OSP) Cu and SAC305–0.05Ni/OSP Cu solder joints. We implemented the fractal dimension characterization and microstructure morphology reconstruction. This is the first time that we applied fractals on such alloys. The morphology reconstruction is important for predicting and designing the optimal microstructure for the advanced desirable properties these alloys. These analyzed parameters are important for the hand-held devices and systems especially for the exploitation. The fractal reconstruction was applied on the prepared microstructures with five different magnifications. The results confirmed successful application of fractals in this area of materials science considering the grains and shapes reconstructions.

Biophysical and condensed matter systems connection is of great importance nowadays due to the need for a new approach in microelectronic biodevices, biocomputers or biochips advanced development. Considering that the living and nonliving systems’ submicroparticles are identical, we can establish the biunivocally correspondent relation between these two particle systems, as a biomimetic correlation based on Brownian motion fractal nature similarities, as the integrative property. In our research, we used the experimental results of bacterial motion under the influence of energetic impulses, like music, and also some biomolecule motion data. Our goal is to define the relation between biophysical and physical particle systems, by introducing mathematical analytical forms and applying Brownian motion fractal nature characterization and fractal interpolation. This work is an advanced research in the field of new solutions for high-level microelectronic integrations, which include submicrobiosystems like part of even organic microelectronic considerations, together with some physical systems of particles in solid-state solutions as a nonorganic part. Our research is based on Brownian motion minimal joint properties within the integrated biophysical systems in the wholeness of nature.

Materials science is highly significant in space program investigation, energy production and others. Therefore, designing, improving and predicting advanced material properties is a crucial necessity. The high temperature creep and corrosion resistance of Ni-based superalloys makes them important materials for turbine blades in aircraft engines and land-based power plants. The investment casting process of turbine blades is costly and time consuming, which makes process simulations a necessity. These simulations require fundamental models for the microstructure formation. In this paper, we present advanced analytical techniques in describing the microstructures obtained experimentally and analyzed on different sample’s cross-sectional images. The samples have been processed on board the International Space Station using the MSL-EML device based on electromagnetic levitation principles. We applied several aspects of fractal analysis and obtained important results regarding fractals and Hausdorff dimensions related to the surface and structural characteristics of CMSX-10 samples. Using scanning electron microscopy (SEM), Zeiss LEO 1550, we analyzed the microstructure of samples solidified in space and successfully performed the fractal reconstruction of the sample’s morphology. We extended the fractal analysis on the microscopic images based on samples solidified on earth and established new frontiers on the advanced structures prediction., publishedVersion

The dielectric properties of Neodymium zinc titanium oxide (NZT) and Neodymium magnesium titanium oxide (NMT) were investigated. The single-phase ceramic was synthesized at various temperatures below 1650[Formula: see text]C. The result shows that the value of temperature of resonant frequency [Formula: see text] for NMT is higher than NZT. Our findings also indicate that the rare earth materials produce high property dielectric materials, despite the fact some elements produce lower negative value of temperature of resonant frequency [Formula: see text]. By doping a compound such as CaTiO3 which has a very positive temperature of resonant frequency ([Formula: see text] ppm/[Formula: see text]C) and a very high relative permittivity [Formula: see text], it is possible to tune NZT and MNT to achieve an excellent dielectric material. This work is under consideration. The results of this scientific research could be very important for modern advance applications in microelectronic miniaturization.

The focus of this study is on the control of layers between grains by applying graph theory. We performed modification of BaTiO3 nanoparticles with Y2O3. The results of capacitance change on submicron level are the part of the measured values on the bulk samples. The original idea is to develop the new approach to use graph theory for networking of electronic parameters between the neighboring grains in order to compare the values measured on the sample, and to present them through the edges in graph between corresponding vertices. Capacitance change with DC bias was measured on bulk samples, and the modified nanoparticles showed stability up to 90 V. After using graph theory with the different number of neighboring grains and on different voltages, it has been shown that capacitance change can be successfully calculated on the layers between grains. Original calculations presented as 1D cases were performed, confirming graph application as a tool with which measured bulk results can be downsized to an appropriate intergranular level, opening the new perspectives in the area of miniaturization and micropackaging.

Donor/acceptor (La/Mn) doped BaTiO3 ceramics, sintered at different temperatures, were studied regarding their microstructure and dielectric properties as well as the dielectric response in a ferroelectric/paraelectric regime. The concentrations of La3+ as donor, ranging from 0.1 to 5.0 at% were used for doping, while a content of Mn4+ as acceptor was at 0.05 at% in all samples. The sintering temperature of codoped samples were 1290? and 1350?C. A reduction in grain size and fine-grained microstructure with average grain size from 0.5 to 2.0 mm was observed in low doped samples, whereas the abnormal growth of individual grains took place in the 2 at% and 5 at% La doped specimens. The dielectric properties of these samples were investigated as a function of frequency (100Hz - 20 kHz) and temperature (20-180?C). The measured results suggested that both the dielectric constants of the ceramics (er at room temperature and ermax at the Curie temperature) decreased as the concentration of La3+ increased. The dielectric permittivity was in the range of 944 to 3200. For samples doped with 0.1 at% La and sintered at 1350?C, the highest dielectric constant value at room temperature (er= 3200) and Curie temperature (er= 5000) were measured. For all measured samples the dissipation factor was less than 0.09. With an increase in La contents, dielectric measurements exhibited shift in the Curie temperature (Tc) towards the low temperature. Using the Curie-Weiss and the modified Curie-Weiss law, Curie's constant C was calculated as well as the parameterg, which describes the deviation from the linear dependence er of T above the phase transformation temperature. The calculated values for g ranged from 1.01 to 1.43. These values indicate a sharp phase transformation in lowdoped and diffuse phase transformation in highly La doped samples. The phase transition was reflected in the values of C that started to decrease with increasing dopant content.

BaTiO3-ceramics is a porous material made out of grains and pores. Such a structure is best explained by fractal nature approach. There is a strong porosity influence on microelectronic properties,...

This paper is focused on the research an improved version of the Boltzmann-Poisson model for BaTiO3-ceramics. In the approximation of one relaxation time, for constant external electrical field, this approach included correct quadratic relation for varistor effect in the case of the Heywang model. Within meso-kinetics, quantum corrected Boltzmann-Poisson model, contains space-time correlations for the probability distribution density function f(r, k, t), lead to correct fractional relaxation velocity description. These new results corresponds to our other research based on electronic particles Brownian motion within its fractal nature.

This research is focused on further developing of application and use of graph theory in order to describe relations between grains and to establish control over layers. We used functionalized BaTiO3 nanoparticles coated with Yttrium-based salt. The capacitance change results on super-microstructure levels are the part of the measured values on the bulk samples. The new idea is graph theory application for determination of electronic parameters distribution at the grain boundary and to compare them with the bulk measured values. We present them with vertices in graph, corresponding with grains, connected with edges. Capacitance change with applied voltage was measured on samples sintered in air and nitrogen, up to 100 V. Using graph theory, it has been shown that capacitance change can be successfully calculated on the layers between grains. Within the idea how to get parameters values at microlevel between the grains and pores, mathematical tool can be developed. Besides previously described 1D case, some original calculations for 2D cases were performed in this study, proving successful graph theory use for the calculation of values at nanolevel, leading to a further minituarization in micropackaging. This is the peer reviewed version of the article: Randjelović, B.M., Mitić, V.V., Ribar, S., Lu, C.-A., Radovic, I., Stajcic, A., Novakovic, I., Vlahovic, B., 2020. Ceramics, materials, microelectronics and graph theory new frontiers. Mod. Phys. Lett. B 34, 2150159. [https://doi.org/10.1142/S0217984921501591] Published version: [https://hdl.handle.net/21.15107/rcub_dais_10032]

Nanomaterials form the main thrust for modern day technological and industrial applications, including but not limited to, super-capacitors, membranes, batteries, filters, sensors, tissue engineering, wound dressing, protecting vesture, reinforcement in composite materials, etc. Ceramic nanofibers are at the forefront of these materials due to their high surface area and tunable nano structures and porosity. However, obtaining nanofibers with a well-developed uniform crystallinity and a perfect morphology is a challenging task. Among various techniques utilized for preparation of nanofibers centrifugal jet spinning covets merits due to its high efficiency production rate, cost adequacy and operational safety. In the present manuscript we report preparation of TiO2 nanofibers by Sol–Gel Course with Centrifugal Jet Spinning using tetrabutyl titanate as main organic titanium precursor. Herein we demonstrate that a well-developed crystallinity and a perfect morphology of TiO2, from Nano to micro-scales, can be achieved after decomposition of polymer and removal of carbon. Effect of various factors such as PVP content, speed of rotation, humidity and heat treatment on the fiber growth was investigated. Effect of variation in soaking time and different temperatures on the TiO2 nanofiber grain growth was also investigated. Phase structure of TiO2 nanofibers was characterized by X-ray diffraction (XRD). Microstructure of the nanofibers was analyzed using Scanning Electron Microscopic (SEM) studies and Transmission Electron Microscope (TEM) studies. Kinetic exponents of grain growth were likewise acquired by with the help of an image processing software. Outcomes of our investigations show that crystallinity and morphology of grains of fibers are highly sensitive to temperature and soaking time. Image analysis demonstrates that sintering temperature greatly affects the crystallinity and grain size of the nanofibers over 700 °C.

The BaTiO3 ceramics applications based on electronic properties have very high gradient scientific and industrial-technological interests. Our scientific research has been based on nano BaTiO3 modified with Yttrium based organometallic salt (MOD-Y). The samples have been consolidated at a sintering temperature of 1350 &deg, C. Within the study, the new frontiers for different electronic properties between the layers of BaTiO3 grains have been introduced. The research target was grain boundary investigations and the influence on dielectric properties. After scanning electron microscopy and dielectric measurements, it has been established that modified BaTiO3 samples with larger grains showed a better compact state that led to a higher dielectric constant value. DC bias stability was also investigated and showed a connection between the grain size and capacitance stability. Analyses of functions that could approximate experimental curves were successfully employed. Practical application of fractal corrections was performed, based on surface (&alpha, s) and pore size (&alpha, p) corrections, which resulted in obtainment of the relation between the capacitance and Curie temperature. Successful introduction of fractal corrections for capacitance-Curie temperature dependence for a set of experimental data is an important step towards further miniaturization of intergranular capacitors.

The grain size and the ferroelectric morphology are the two most important factors in the research and development of advanced dielectric devices. It is important to synthesize nanostructures in order to achieve optimal grain size and inhibit grain growth while controlling the sintering parameters. It is also important to find new methods to study the grain growth during densification. BaTiO3 films were successfully obtained via the sol-gel spin coating method. In this paper, we report the deposition of nanostructured BaTiO3 thin film by spin coating of sol-gel precursors. The densification, grain growth and microstructure evolution have been studied. Moreover, a novel physical and mathematical fractal analysis have been applied successfully to the densification and nano grain growth of BaTiO3 thin film. The discrepancy between the fractal dimension and the grain growth with increasing temperatures and soaking time are presented and discussed. This is the peer-reviewed version of the article: Aminirastabi, H., Xue, H., Mitić, V.V., Lazović, G., Ji, G., Peng, D., 2020. Novel fractal analysis of nanograin growth in BaTiO3 thin film. Materials Chemistry and Physics 239, 122261. [https://doi.org/10.1016/j.matchemphys.2019.122261] Published version: [https://hdl.handle.net/21.15107/rcub_dais_6886]

Nowadays, there is a very high importance of composite research and variety of their applications in the modern world. In that sense, we researched hollow glass capillaries filled with dissolved Grubbs catalyst (GC) and dicyclopentadiene (DCPD) were incorporated into a fiber-reinforced epoxy with the aim of improving the flow of healing agents to the crack site. The morphological investigation of the crack site was performed using field emission scanning electron microscopy (FESEM), showing the difference between the samples depending on the used solvent. The software analysis of sample photographs has been performed by calculating the fractured/healed surface area of the samples, revealing that approximately 20% of the volume was affected by the impact. Fourier transform infrared spectroscopy (FTIR) revealed that poly (dicyclopentadiene) (PDCPD) formed at the healed interface. However, the FTIR investigation of catalyst stability in different solvents showed structural changes in GC and partial deactivation. The mechanical tests of the samples showed that a recovery of 60% after 24 h at room temperature could be achieved through the use of a solvent and very low concentration of GC. The performed research results are a good base to develop the model for predicting the processes and morphology, with the goal to design the final mechanical and in the future, thermal, properties in advance. This opens a new direction for future research in the field of composite healing. © 2020 Elsevier B.V.

The effect of rare earth ions on dielectric permittivity, dielectric losses and microstructure of barium titanate ceramics doped with Ho, Er and Yb at the concentrations of 0.05 wt% to 1.0 wt% was investigated. The doped BaTiO 3 were obtained by solid-state sintering reaction at a temperature of 1320°C in air atmosphere. The electrical properties were measured in the temperature interval from 30°C to 180°C at different frequencies. The results of electrical investigation showed that samples doped with a low additives concentration, with a spherical and large grains, have high dielectric constant value. e r at Curie temperature is 4250, 3828 and 3011 for 0.05 wt% Ho, Er and Yb respectively. By increasing dopant concentration and decreasing grain size, the dielectric permittivity value decreases. All investigated samples have low values of dielectric losses ranged from 0.01 to 0.09. Also, samples with a low concentration of additives follow Curie-Weiss‘s law. The Curie temperature of doped samples is slightly lower than Curie temperature of the undoped ceramics and it is 126-128 °C. The Curie constant $C$ for all examined samples increases with increasing dopant concentration, so that the highest values were measured for the samples doped with 1.0 wt% of the additive.

Historically, although the first indications for the use of lasers in general were in dentistry, coming as a relief from the sound of the drill and mechanical contacts, it still seems somewhat that the entry in various ways of lasers in dentistry has been slower. This is somewhat true for the situation at the continents (e.g. USA much later approved the application relative to Europe). This paper analyzes the potential and existing applications of lasers in dentistry in a wide range of existing types, including interaction with dental tissues, in terms of surgical applications, on living tissue, the prosthetic area of applications and therapeutic doses. There is another special feature that can be recognized is the precise determination of the color of the material (teeth and prosthetics) and in general the determination of the composition of the material including classic, but also modern laser techniques (LIBS, complimentary techniques, tooth tissue, bone) and especially in the case of the first Q switch systems related to pain reduction, because the short pulse favors the intervention rate (ns, ps and fs). Special attention should be paid to modeling of interaction and analysis with the appropriate software support.

Interlayer transport of charges and carriers of 2D nanomaterials is a critical parameter that governs the material and device performance in energy storage applications. Inspired by multilevel natural bamboo-membrane with ultrafast water and electrolyte transport properties to support its super-rapid growth rate, 2D–2D multilevel heterostructured graphene-based membranes with tailored gradient interlayer channels are rationally designed for achieving ultrafast interlayer ion transport. The bioinspired heterostructured membranes possess multilevel interlayer spacing distributions, where the closely packed layers with sub-nanosized interlayer space provide ultrafast confined interlayer ion transport, while the loosely stacked outer layers consisting of open channels with large distances up to few micrometres are favorable for rapid wetting and penetration of liquid electrolytes. The combination of advantages of large-size open channels and nanosized confined channels offers ultrafast electrolyte wetting and permeation and interlayer ion transport and provide the devices with superior volumetric capacity as free-standing electrodes for rechargeable batteries.

Hydroxyapatite scaffold is a type of bio-ceramic. Its cellular design has similarities with the morphologies in nature. Therefore, it is very important to control the structure, especially the porosity, as one of the main features for bio-ceramics applications. According to some literature, freeze casting can form the shape of dendrites and remain a foam structure after ice sublimation. Ice nucleation became more heterogeneous with the aid of printing materials during freeze casting. This procedure can even improve the issue of crack formation. In this paper, we studied the mechanical properties of hydroxyapatite scaffold. We also analyzed the porosity by fractal nature characterization, and successfully reconstructed pore shape, which is important for predicting ceramic morphology. We applied SEM analysis on bio-ceramic samples, at four different magnifications for the same pore structure. This is important for fractal analysis and pores reconstruction. We calculated the fractal dimensions based on measurements. In this way, we completed the fractal characterization of porosity and confirmed possibilities for successful porous shapes reconstruction. In this paper, we confirmed, for the first time, that fractal nature can be successfully applied in the area of porous bio-ceramics.

After pioneering attempts for the introduction of graph theory in the field of ceramics and microstructures, where 1D and 2D graphs were used, in this paper we applied 3D graphs for the breakdown voltage calculation in BaTiO3 sample with some predefined constraints. We have described the relations between grains in the sample and established a mathematical approach for the calculation of breakdown voltage using experimental results. As a result, we introduced mapping between the property of sample and grain structure, then between the grain structure and mathematical graph, using various crystal structures. The main idea was to apply 3D graph theory for the distribution of electronic parameters between the neighboring grains. With this study, we successfully confirmed the possibilities for applications of graphs as a tool for the determination of properties even at the intergranular level.

In this study, the electrical resistivity (ρ) and PTC effect of Er doped BaTiO3 ceramics are investigated. The concentrations of Er2O3 in the doped samples vary from 0.01 to 1.0 at% Er. The samples are prepared by the conventional solid state reaction, and sintered at 1320° and 1350°C in air atmosphere for 4 hours. The SEM analysis shows that all of measured samples are characterized by polygonal grains. The uniform and homogeneous microstructure with grain sizes from 20 to 45μm is the main characteristic of the low doped samples (0.01 and 0.1 at% Er). For the samples doped with the higher dopant concentration (0.5 and 1.0 at%) the average grains sizes have been ranged from 5 to 10 μm. The electrical resistivity is measured in the temperature range from 25°C to 170°C, at frequencies 1 kHz, 10 kHz and 100 kHz. The electrical resistivity values, measured at frequency of 1 kHz and room temperature, have been ranged from 1.62•104 Ωcm to 4.24∙104 Ωcm, for samples sintered at 1320°C and from 1.43•104 Ωcm to 1.94∙104 Ωcm, for samples sintered at 1350°C. A nearly flat and stable electrical resistivity-temperature response is characteristic for all samples at the temperature range from 25°C to 120°C. Above this temperature, the electrical resistivity increases rapidly. At 170°C the value of electrical resistivity is ranged 9.84•104 Ωcm -1.62•105 Ωcm, for Tsin=1320°C, and 6.11•104 Ωcm 1.32•105 Ωcm, for Tsin=1350°C. The electrical resistivity decreases with concentration increment up to 0.5 at%, while above 0.5 at% it increases. Also, with increasing frequency, ρ decreases for a few orders of magnitude. [172057: Directed synthesis, structure and properties of multifunctional materials]

Fluctuation of wind speed affects wind energy systems since the potential wind power is proportional the cube of wind speed. Hence precise prediction of wind speed is very important to improve the performances of the systems. Due to unstable behavior of the wind speed above different terrains, in this study fractal characteristics of the wind speed series were analyzed. According to the self-similarity characteristic and the scale invariance, the fractal extrapolate interpolation prediction can be performed by extending the fractal characteristic from internal interval to external interval. Afterward neuro-fuzzy technique was applied to the fractal data because of high nonlinearity of the data. The neuro-fuzzy approach was used to detect the most important variables which affect the wind speed according to the fractal dimensions. The main goal was to investigate the influence of terrain roughness length and different heights of the wind speed on the wind speed prediction.

Sm/Mn codoped BaTiO 3 ceramics were investigated for their microstructure and dielectric characteristics. The powders were prepared by the conventional solid state procedure. The concentration of Sm 2 O 3 as a donor dopant has been kept from 0.1 up to 5.0 at%. The content of MnO 2 as acceptor was kept constant at 0.05 at% Mn in all samples. The specimens were sintered at 1290 °C, 1320 °C and 1350 °C in an air atmosphere for two hours. A mainly uniform and homogeneous microstructure with average grain size ranging from 0.3 µm to 2.0 µm was observed in low doped samples. In highly doped samples, apart from the fine grained matrix, the appearance of local area with secondary abnormal grains was observed. The dielectric properties were investigated as a function of frequency and temperature. The low doped samples exhibit the high value of dielectric permittivity at room temperature and the greatest change at the Curie temperature. The highest value of dielectric constant ( e r =6800) was measured for 0.1Sm/BaTiO 3 samples sintered at 1350 °C. A nearly flat permittivity-temperature response and lower values of e r were obtained in specimens with 2.0 and 5.0 at% additive content. The dielectric constant increases with the increase of sintering temperature. The dissipation factor ranged from 0.01 to 0.22 and decreases with the increase of sintering temperature. The Curie constant ( C ), Curie-Weiss temperature ( T 0 ) and critical exponent of nonlinearity ( γ ) were calculated using a Curie-Weiss and modified Curie-Weiss law. The highest value of Curie constant (C=9.06·10 5 K) was measured in 0.1 at% doped samples. The Curie constant decreased with increasing dopant content. The γ values, ranging from 1.001 to 1.58, point out the sharp phase transition in low doped samples, and the diffuse phase transition in heavily doped BaTiO 3 samples.

This research is based on the idea to design the interface structure around the grains and thin layers between two grains, as a possible solution for deep microelectronic parameters integrations. The experiments have been based on nano-BaTiO3 powders with Y-based additive. The advanced idea is to create the new observed directions to network microelectronic characteristics in thin films coated around and between the grains on the way to get and compare with global results on the samples. Biomimetic similarities are artificial neural networks which could be original method and tools that we use to map input-output data and could be applied on ceramics microelectronic parameters. This mapping is developed in the manner like signals that are processed in real biological neural networks. These signals are processed by using artificial neurons, which have a simple function to process input signal, as well as adjustable parameter which represents sensitivity to inputs. The integrated network output presents practically the large number of inner neurons outputs sum. This original idea is to connect analysis results and neural networks. It is of the great importance to connect microcapacitances by neural network with the goal to compare the experimental results in the bulk samples measurements and microelectronics parameters. The result of these researches is the study of functional relation definition between consolidation parameters, voltage (U), consolidation sintering temperature and relative capacitance change, from the bulk sample surface down to the coating thin films around the grains. © 2020 World Scientific Publishing Company.

Consolidation parameters have influence and can be used to control structure of BaTiO3 based materials. Microstructure and dielectric properties of Yb2O3 doped BaTiO3-ceramics, sintered from 1320 °C to 1380 °C have been investigated. The correlation between microstructure, capacity and dielectric properties of doped BaTiO3-ceramics, based on fractal geometry and micro-contact surfaces, has been developed. Using the fractal descriptors of the grains contact surface, the microstructure reconstruction constituents, as grains and pores shapes or intergranular contacts, has been successfully done. Obtained results indicated that fractal analysis contact surfaces descriptors of different shapes are very important for the prognosis of BaTiO3-ceramics microstructure and capacity and dielectric properties. The morphology of ceramics grains pointed out the validity of developing new structure analytical methods, based on different grains’ shape geometries. The grains contact structure based on Minkowski hull is presented as a new tool for BaTiO3-ceramics materials structure research. The materials properties prognosis are determined according to the correlations synthesis–structure–property, within Minkowski hull fractal frame. © 2019, © 2019 Taylor & Francis Group, LLC.

The new frontiers open different directions within the higher and deeper knowledge structure using unemployed nano sizes domains. The BaTiO3 and other ceramic materials have fractal configuration nature based on three phenomena. First, ceramic grains have fractal shape looking as a contour in cross section or as a surface. Second, there is the so-called “negative space” made of pores and intergranular space. Third, there is fractal Brownian motion (fBm) within the material, during and after sintering, in the form of microparticle flow: ions, atoms, and electrons. Here, we took upon ourselves the task of extending Coble’s model, with already generalized Euclidean geometries, by fractal nature correction. These triple factors make the very peculiar microelectronic environment electro-static/dynamic combination. The stress is here set on inter-granular micro-capacity in function of higher energy harvesting and storage. Constructive fractal theory allows identifying micro-capacitors with fractal electrodes. The method is based on the iterative process of interpolation which is compatible with the grain model itself. Inter-granular permeability is taken as the fundamental thermodynamic parameter function of temperature and enthalpy (Gibbs free energy), which are very important for a structure-energy relation.

The world's perennial need for energy and microelectronic miniaturization brings with it a broad set of technological and scientific challenges. Materials characterized by precise microstructural architectures based on fractal analysis and ranging in size down to nano scale represent an important avenue for finding novel solutions. Deep materials structure hierarchies of this type open new possibilities in capacity according to the Heywang model, especially when extended by a fractals approach and intergranular relationships supported and recognized by their fractal nature. These developments are opening new frontiers in microelectronics miniaturization. They build on early fractal applications that were used as tools in miniaturization research and also provided application perspectives for diverse energy technologies. In other words, fractals, as a crucial concept of modern theoretical-experimental physics and materials sciences, are tightly linked to higher integration processes and microelectronics miniaturization. They also hold potential for meeting the energy exploitation challenge. In this research context, for the first time we experimentally and theoretically investigated the electrostatic field between the grains within fractal nature aspects. It is essentially a theoretical experiment based on samples of experimental microstructures imaged with SEM, as previously published in a number of other papers. We now take the research a step further by consolidating the experimental samples with respect to the predicted distribution of grains and pores within the sample mass. We make an original contribution by opening the frame of scale sizes with respect to the technical processes of consolidation. This lets us predict the constitutive elements of the microstructures – approximately equidistant grains and pores. In this paper we define in a practical manner the final target elements for experimental consolidation of real samples. It is the main bridge between a designed microstructure and related characteristics – for example, fractal dimensions and final properties of next-generation fractal microelectronics. Peer-reviewed manuscript: [https://hdl.handle.net/21.15107/rcub_dais_4795]

La/Mn codoped BaTiO 3 ceramics with different La 2 O 3 content, ranging from 0.3 to 1.0 at% La, together with undoped BaTiO 3 ,were investigated regarding their microstructure and dielectric properties. The content of MnO 2 kept constant at 0.01 at% Mn in all investigated samples. La/Mn codoped and undoped BaTiO 3 were obtained by a modified Pechini method and sintered in air at 1300 0 C for two hours. The homogeneous and completely fine-grained microstructure with average grain size from 0.3 to 1mm was observed in samples doped with 0.3 at% La. In high doped samples, apart from the fine grained matrix, the appearance of local area with secondary abnormal grains was observed. The dielectric permittivity and dissipation factor were investigated as a function of frequency and temperature. Dielectric permittivity of doped BaTiO 3 was in the range of 3945 to 12846 and decreases with increase of additive content. The highest value of dielectric constant at room temperature (e r = 12846) and the greatest change at Curie temperature (e r = 17738) were measured in 0.3at% La doped samples. Dissipation factor was range from 0.07 to 0.62 for all investigated samples. The Curie constant (C) and Curie-Weiss temperature (T 0 ) together with critical exponent of nonlinearity (g) were calculated using a Curie-Weiss and modified Curie-Weiss law. The Curie constant increase with increasing dopant content and the highest values were measured in 1.0 La doped samples. The obtained values of g is in the range from 1.04 to 1.53 and pointed out the sharp phase transformation from ferroelectric to paraelectric phase at Curie temperature.

In this paper, we present experimental data of static fractals and compare the results with theoretical analysis obtained using dynamic particle simulation. The fractal simulator presented in this manuscript is pioneer work and it is the base of the future concrete and industrial applications. We have examined sintered ceramic samples formed using several different additives, as fabricated using various parameters, sintering temperature and time. SEM analyses were performed on samples as a part of the experimental characterization procedure. Based on microstructures, sets of points have been selected as a primary database input for the theoretical-experimental simulation to model the processes that describe the experiment. For all grain and pore analyses, the fractal nature is recognized as a matter of substantial influence on material characteristics. All of our experimental and theoretical-experimental procedures are based on the construct that reconstruction of the grain and pore fractal nature is of enormous importance for microstructure property prognoses. The method presented here can be used to simplify and simulate, in real time, the interaction of a few thousand electrically charged particles possessing different masses through formulations based on Maxwell?s electromagnetic equations. Particles in simulation interact with alternating (or static) electromagnetic fields and with static ceramics surface at the same time. All values are treated numerically. The fractal simulator consists of two components, a structure fractal generator, and field simulator. The functions for particle motion can be implemented and changed within the program in real time. The algorithm is written in the Delphi programming environment. The main result of this paper describes a quite new approach in the analysis of material microstructure properties towards programming-prognoses of the final properties of ceramic materials using the fractal nature within the fractal field simulator that generates structures, grains, and pores. The new simulator algorithm is developed as the important tool for the realization of the much ambitious project - simulation and realization of the Tesla?s Fountain in ceramics. The concrete results will follow with this project realization in near future.

In the process of predicting materials properties, it is necessary to predict microstructures. This is important for ceramic materials, for the purpose of miniaturization and for a higher level of integration. Although the method of material structure reconstruction is for the first time used on BaTiO3-ceramics by these authors, it can also be used for silicate, refractory and other ceramics, and, for any powder-based material. The reconstruction is based on the grain perimeter fractal analysis and the Richardson method. The main contribution of this paper is establishing the relationship between the electronic properties of BaTiO3-ceramics and its microstructural fractal nature. Similar relations can be used for any ceramics or even any materials. The samples consolidation includes both powder pressing (cold sintering phase) and sintering in a furnace (hot sintering phase). The fractal nature characterization has a very important role from the powder phase up to the final microstructure, through which structures it directly impacts electro-physical and other ceramics properties. Thereby, the new possibilities in the microstructure characterization applications are directly introduced to an engineering system, providing the new solutions related to computer aided support. This creates new industrial production and application possibilities, especially in the process of ceramics material consolidation, now based on microstructural properties, which is providing a basis for “fractal electronics’’ development. © 2018 Elsevier Ltd

The electrical resistivity (ρ) of Yb doped BaTiO 3 ceramics in function of temperature is investigated in this article. The concentrations of additive in the BaTiO 3 doped samples were ranged from 0.01 to 1.0 at % Yb. The conventional solid state reaction is used for preparation of initial samples. The samples are sintered at 1320° and 1380°C in air atmosphere for 4 hours. The electrical resistivity is measured in temperature range from 25°C to 170°C at versatile frequencies. To a temperature of 120°C, resistivity slightly increases with increasing of temperature, but above this temperature the resistivity increases rapidly. The electrical resistivity at the room temperature decreases with increasing concentration of Yb and gain the minimum at about 0.5 at% of donor concentration (low doping level). Over 0.5 at%, ρ increases rapidly with increment of donor content (high doping level). Also, the increment of frequency causes decrement of electrical resistivity for a few order of magnitude.

The specimens of BaTiO3 doped with 0.01, 0.1 and 0.5wt% of Er2O3 or Ho2O3 used for this investigation were prepared by the conventional solid state reaction. The specimens were sintered at 1350 degrees C in an air atmosphere for 4hours.The grain size and microstructure characteristics for various samples and their phase composition was carried out using a scanning electron microscope SEM equipped with EDS system. SEM analysis of Er/BaTiO3 and Ho/BaTiO3 doped ceramics showed that in samples doped with a low level of rare-earth ions, the grain size ranged from 10-60m, while with the higher dopant concentration the abnormal grain growth is inhibited and the grain size ranged between 2-10m.We also applied the fractal method in microstructure analysis of sintered ceramics especially as influence on dielectric properties of BaTiO3 ceramics. These fractal effects have been used for better understanding of intergranular capacitors.

We study single electron tunneling from the barrier in the binary InAs/GaAs quantum structure, including quantum well (QW) and quantum dot (QD). Tunneling is described in the terms of localized/delocalized states and their spectral distributions. Modeling is performed using the phenomenological effective potential approach for InAs/GaAs heterostructures. The results for the two and three-dimensional models are presented, focused on the effect of QD-QW geometry variations. The relation to the PL experiments is shown.

The materials based on BaTiO3 can be controlled using different technological parameters and different additives. The influence of different temperature levels of sintering (1320°C, 1350°C and 1380°C) on the size of contact area for 0.1% Ho2O3 doped BaTiO3-ceramics has been investigated. Microstructural investigations were carried out using scanning electron microscopy (JEOL-JSM 5300) equipped with EDS (QX 2000S) system. Grain size distribution was determined by quantitative metallography method. The new correlation between microstructure and dielectric properties of doped BaTiO3-ceramics based on fractal geometry and contact surface probability is recently developed. The presented results indicate that statistical model of contact surfaces is important for the prognosis of BaTiO3-ceramics microstructure and dielectric properties. [Projekat Ministarstva nauke Republike Srbije, br. 172057: Directed synthesis, structure and properties of multifunctional materials i br. III44006]

In this study, the feasibility of using fly ash to manufacture high-temperature mortars was investigated. The investigation was set to define preliminary characteristics of new types of mortars based on ordinary and/or refractory cement with fly ash addition, and to establish mutual correlation between thermally induced changes of mineral phases, microstructure, and final performances of the mortars. New mortars, made up of 21% cement (PC-CEM I 42.5R/HAC-Secar 70/71), 70% river sand, and 9% fly ash, were chemically, physically, and mechanically characterized to determine possibilities of fly ash re-utilization for high-temperature purposes. The fly ash samples, which originated from four different power plants, were mechanically activated. Mortars were heat-treated up to 1300°C in a laboratory tunnel furnace with retention time 2 h. Thermal stability of crystalline phases were studied by differential thermal analysis (DTA); thermally induced changes in mineral phase composition were analyzed by XRD; and microstructure were investigated by scanning electron microscopy. Correlated results of DTA, XRD, and SEM analyses indicated initiation of sintering processes at approximately 1300°C and formation of thermally stable minerals (rankinite, gehlenite, anorthite, cristobalite). The investigation highlights a sustainable approach of using fly ash in developing ecofriendly mortars for high-temperature application. © 2013 The American Ceramic Society.

In this paper, we develop the new physical-mathematical time scale approach-model applied to BaTiO3-ceramics. At the beginning, a time scale is defined to be an arbitrary closed subset of the real numbers R, with the standard inherited topology. The time scale mathematical examples include real numbers R, natural numbers N, integers Z, the Cantor set (i.e. fractals), and any finite union of closed intervals of R. Calculus on time scales (TSC) was established in 1988 by Stefan Hilger. TSC, by construction, is used to describe the complex process. This method may be utilized for a description of physical, material (crystal growth kinetics, physical chemistry kinetics - for example, kinetics of barium-titanate synthesis), bio-chemical or similar systems and represents a major challenge for nowadays contemporary scientists. Generally speaking, such processes may be described by a discrete time scale. Reasonably it could be assumed that such a ?scenario? is possible for discrete temperature values as a consolidation parameter which is the basic ceramics description properties. In this work, BaTiO3-ceramics discrete temperature as thermodynamics parameter with temperature step h and the basic temperature point a is investigated. Instead of derivations, it is used backward differences with respect to temperature. The main conclusion is made towards ceramics materials temperature as description parameter.

The Bayer process is the main industrial process covering 90 % of global production of alumina. The sintering process deals with the medium and low grades of bauxite resource. During the alumina production process, red mud is generated as a waste rock which consists of: hematite, Goethite, quartz, boehmite, calcite, tricalcium aluminate, zinc and magnesium oxides, sodium hydroxide etc. Due to high viscosity of the mud, prior to transport to the waste industrial water is added in the share of 10–15 % prior to transport to the waste disposal dump so that the pipeline transport would be facilitated. What makes red mud a hazardous pollutant is the alkaline liquid phase (Zlatičanin et al. in Prot Mater 53:292–298, 2012, Paramguru et al. Extr Metall Rev 26:1–29, 2005) [1, 2]. From the aspect of stored quantities, red mud represents a significant environmental problem (Zlatičanin et al. in Prot Mater 53:292–298, 2012) [1]. A large number of methods for sustainable disposal of red mud was developed, however, it a tendency to use the red mud in other production process, up to 20 % of it until 2025. The potential for utilization of red mud is seen making masonry products, ceramic tiles, in replacement of a part of cement or aggregate, as a component in self-compacting concretes, geopolymers. The paper provides a review of the developed methods for storage of red mud, with a goal of sustainability and cost-effectiveness. Simultaneously, the paper provides the review of potential application of red mud as a component of building materials. In the experimental part was considered the usage of red mud as a mineral admixture for making self-compacting concrete.

The properties of seven montmorillonite-rich bentonites of different geological origin were investigated prior and subsequent to mechano-chemical processing in an ultra-centrifugal mill. The objective of the experiment was altering the bentonite types and activation parameters in order to determine the optimal milling conditions that produce material which is physico-mechanically and microstructurally applicable as a binder replacement and sorbent in the construction composites. The efficiency of bentonite activation was assessed by chemometrics and Artificial neural networks mathematical modeling. Principal component analysis and analysis of variance were used in the observation of the influence of input variables (bentonite chemical composition) and process parameters (milling duration, rotor velocity) on the product characteristics: density, specific surface area, grain size and distribution, cation exchange capacity, melting point, compressive strength, shrinkage and porosity. When the ANN models for the observed responses, related to predicted bentonite characteristics and quality, were compared to experimental results, they correctly predicted the responses. The processed data also adequately fitted to the regression second order polynomial models. The SOP models, which showed r 2 values from 0.357 to 0.948, and were able to predict the observed responses in a wide range of processing parameters, while ANN models performed high prediction accuracy (0.776–0.901) and can be considered as precise for response variables prediction. The combination of the conducted mathematical analyses showed that that increase/decrease in output values was stabilized after 30 min of activation. Mathematically attained interpretations were correlated with the results of the instrumental analyses (XRD, DTA/TG, SEM) to confirm the adoption of B6 bentonite as a preferable type and 30 min as an optimal milling time for acquiring quality of clay powder that will be used in structural and thermal applications.

Since the wind speed fluctuation could cause large instability in wind energy systems it is crucial to develop a method for precise estimation of the wind speed fluctuation. Fractal interpolation of the wind speed could be used to improve the accuracy of the estimation of the wind speed fluctuation. Based on the self-similarity feature, the fractal interpolation could be established from internal to external interval. In this article fractal interpolation was used to improve the wind speed fluctuation estimation by soft computing methods. Artificial neural network (ANN) with different training algorithms were used in order to estimate the wind speed fluctuation based on the fractal interpolation This is the peer-reviewed version of the article: Petković, D., Nikolić, V., Mitić, V.V., Kocić, L., 2017. Estimation of fractal representation of wind speed fluctuation by artificial neural network with different training algorothms. Flow Measurement and Instrumentation 54, 172–176. [https://doi.org/10.1016/j.flowmeasinst.2017.01.007]

In this paper we develop the new physical-mathematical time scale kinetic approach-model applied on organic and non-organic particles motion. Concretely, here, at first, this new research approach is based on enzyme particles dynamics results. At the beginning, a time scale is defined to be an arbitrary closed subset of the real numbers R, with the standard inherited topology. Mathematical examples of time scales include real numbers R, natural numbers N, integers Z, the Cantor set (i.e. fractals), and any finite union of closed intervals of R. Calculus on time scales (TSC) was established in 1988 by Stefan Hilger. TSC, by construction, is used to describe the complex process. This method may utilized for description of physical (classical mechanics), material (crystal growth kinetics, physical chemistry kinetics—for example, kinetics of barium-titanate synthesis), (bio)chemical or similar systems and represents major challenge for contemporary scientists. In this sense, the Michaelis-Menten (MM) mechanism is the one of the best known and simplest nonlinear biochemical network which deserves appropriate attention. Generally speaking, such processes may be described of discrete time scale. Reasonably it could be assumed that such a scenario is possible for MM mechanism. In this work, discrete time MM kinetics (dtMM) with time various step h, is investigated. Instead of the first derivative by time used first backward difference h. Physical basics for new time scale approach is a new statistical thermodynamics, natural generalization of Tsallis non-extensive or similar thermodynamics. A reliable new algorithm of novel difference transformation method, namely multi-step difference transformation method (MSDETM) for solving system of nonlinear ordinary difference equations is proposed. If h tends to zero, MSDETM transformed into multi-step differential transformation method (MSDTM). In the spirit of TSC, MSDETM describes analogously MSDTM.

In this study, in order to establish grain shapes of sintered ceramics, new approach on correlation between microstructure and doped BaTiO3 -ceramics properties based, on Voronoi model and mathematical statistics calculations on fractal geometry, has been developed. BaTiO3-ceramics doped with Yb2O3 (from 0.1 to 1.0wt% of Yb) were prepared by using conventional solid state procedure and were sintered from 1320°C to 1380°C for four hours. The microstructure of sintered specimens was investigated by Scanning electron microscope JEOL-SEM-5300. For better and deeper characterization and understanding of the ceramics material microstructure, the methods which include the fractal nature structure, and also Voronoi model and mathematical statistics calculations, are applied. In our research the Voronoi is one specific interface between fractal structure nature and different stochastically contact surfaces, defined by statistical mathematical methods. Also, the Voronoi model practically provided possibility to control the ceramics microstructure fractal nature. Mathematical statistic methods enabled establishing the real model for the prognosis based on correlation: synthesis-structures-properties. [Projekat Ministarstva nauke Republike Srbije, br. 172057 i br. III44006]

Metal-endings are integral part of different ultrasonic sandwich transducers. In this paper a new Matlab/Simulink 3D model of the finite metal rings and discs of various dimensions is realized. With this model, which describes both the thickness and the radial resonant modes, and the coupling between them, mechanical impedance of the sample can be easily computed. Resonance frequency-length curves for rings and disks with various materials and for different selected dimensions are given. Also, comparisons of the different approaches in determining of their resonant frequencies are shown. The proposed Matlab/Simulink model requires simpler implementation than other analytical models. That enabled modifying of 1D theory and simplified modelling and projecting of the ultrasonic sandwich transducers with short-endings. Finally, the computed and experimental results are compared. [Projekat Ministarstva nauke Republike Srbije, br. TR33035, br. III43014 i br. OI172057]

Sintering process is a complex of different synergetic effects during the ceramics materials consolidation. The microstructural level properties control is very important as a stage in advanced materials prognosis. SEM analysis of Yb/BaTiO3 doped ceramics showed that in samples doped with a low level of dopant and sintered at higher temperatures the grain size ranged from 10-60?m, while with the higher dopant concentration the grain size ranged between 2-15?m. The morphology of sintered BaTiO3-ceramics grains points out the validity of developing new structure analytical methods based on different geometries of grains' model systems. The idea of electrical properties of BaTiO3-ceramics being influenced by intergrain microcontacts can be successfully followed if we start with the two-sphere Coble?s model and also the correction of the Coble?s model. In this paper, the grains contact models based on spherical, ellipsoidal and polyhedral geometries are presented making a new modeling tool for structure research of BaTiO3-ceramics materials. Intergranular impedance analysis of grains clusters was also introduced. Obtained results enabled establishment of interrelation between structural and electrical parameters.

Mixtures of BaCO(3)-ZnO-TiO(2) were mechanically activated using high-energy planetary ball mill during 20, 40 and 80 min. As the time of mechanical activation increased, the decrease in particle size was observed. The effect of milling on microstructure was investigated by scanning electron microscopy, as well. Sintering process was performed in air at 1100 and 1200 C for 2 h. Various phases are present within mixtures sintered at 1100 and 1200 degrees C, and almost pure BaZn(2)Ti(4)O(11) phase was obtained after 80 min of milling and sintering at 1200 degrees C for 2 h. (C) 2010 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Kaolinite and bentonite clay powders mixed with active additives, based on Mg(NO3)2 and Al(NO3)2, sintered at high temperatures produce very porous ceramics with microcrystalline and amorphous regions and highly developed metalized surfaces (mainly with magnesium surplus). Microstructure investigations have revealed non-uniform and highly porous structure with broad distribution of grain size, specifically shaped grains and high degree of agglomeration. The ceramics samples were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction analysis (XRD) and IR spectroscopy analysis, prior and after treatment in ?synthetic water?, i.e. in aqueous solution of arsenic-salt. Grain size distribution for untreated and treated samples was done with software SemAfore 4. It has shown great variety in size distribution of grains from clay powders to sintered samples.

La/Mn codoped BaTiO3 with different La2O3 content, ranging from 0.1 to 5.0 at% La, was investigated regarding their microstructural and dielectric characteristics. The content of 0.05 at% Mn was constant in all investigated samples. The samples were sintered at 1320?C and 1350?C for two hours. Microstructural studies were done using SEM and EDS analysis. The fine-grained microstructure was obtained even for low content of La. The appearance of secondary abnormal grains with serrated features along grain boundaries was observed in 1.0 at% La-BaTiO3 sintered at 1350?C. Nearly flat permittivity-temperature response was obtained in specimens with 2.0 and 5.0 at% La. Using the modified Curie-Weiss law a critical exponent ? and C' were calculated. The obtained values of ? pointed out the diffuse phase transformation in heavily doped BaTiO3 and great departure from the Curie-Weiss law for low doped ceramics.