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In this research, lead-free piezoelectric ceramic 0.94Bi0.5Na0.5TiO3–0.06BaTiO3 (BNT–BT)/Portland cement (PC) composites have been fabricated for use as sensor in structural health monitoring applications. BNT–BT ceramic particles were mixed with Portland cement using ceramic particles content of 30–60 vol.% to form 0–3 connectivity pattern BNT–BT/PC composite. The acoustic impedance, compressive strength, dielectric, ferroelectric and piezoelectric properties of the composites were investigated as a function of ceramic content. The results indicated that the BNT–BT ceramic content of ≈ 40–60 vol.% are the optimal BNT–BT ceramic contents for acoustic impedance matching between composite and concrete structure. The compressive strength was found in the region of 28.19–35.30 MPa for BNT–BT/PC composites is close to that of normal concrete. The dielectric constant (er) value of composites increased as BNT–BT ceramic content increased, while the dielectric loss value reduced with higher BNT–BT ceramic content. The BNT–BT ceramic content in these composites has a beneficial effect on the ferroelectric behavior. Moreover, composite with BNT–BT ceramic content of 60 vol.% exhibited the highest piezoelectric coefficient ( $${d}_{33}$$ ) value of 42 pC/N. The piezoelectric voltage coefficient ( $${g}_{33}$$ ) of BNT–BT/PC composites was found to be in the range of 13.96 mV m/N to 17.00 mV m/N. Furthermore, the er and $${d}_{33}$$ values of composites were close to the cubes model. According to the results, it is noted that these composites have good compatibility with concrete structure and has the potential for use as sensor in structural health monitoring applications.

Smart composites, which are composed of piezoelectric ceramics and cement-based materials, have been developed for sensing and health monitoring of concrete infrastructure. Barium titanate (BT)-Portland cement (PC)-polyvinylidene fluoride (PVDF) composites with 40-60 vol.% BT particles (with a median size of ~ 425 µm) and 0-7 vol.% PVDF were fabricated by the pressing and curing method. The effects of the PVDF content on the acoustic impedance (Zc), dielectric constant (er), piezoelectric charge coefficient (d33) and piezoelectric voltage coefficient (g33) of the BT-PC-PVDF composites were investigated. Increasing the PVDF content in the composites led to a decrease in the Zc value so that it approached that of concrete. The PC phase was replaced by the PVDF phase in the BT-cement-based composites to reduce the leakage current in these composites. As a result, the piezoelectric properties of the BT-PC-PVDF composites improved noticeably. BT contents of 50 and 60 vol.% and a PVDF of 5 vol.% had the highest d33~24-25 pC/N. Moreover, the composite with 50 vol.% BT and 5 vol.% PVDF had the highest piezoelectric voltage coefficient herein (g33=14.6 × 10-3 V∙m/N).

PLZT ceramics containing 9 mol% La and 50–70 mol% Zr were prepared by two-stage sintering to enhance the densification and the microstructure. Dielectric properties were investigated and the phase ...

Quantum dots (QDs) are materials grown in confined dimension also known as 0D materials. QDs can be synthesized in many shapes and forms through various methods making the materials extremely versatile and can be fine-tuned for appropriate applications. Among the potentially scalable methods, Electrochemical process is considered as one of the top-down approaches with the highest potential for scalability and easy-to-process methodology while electrolyte and pH level can play various important roles on the final product. In this work, we grew and studied the effect of electrolytic solution in the growth of graphene quantum dots (GQDs) in colloidal forms using cheap graphite as precursor in KCl and NaOH as electrolytes in various concentrations. It can be inferred from our results that when KCl and NaOH were used in combination with citric acid, the optoelectrical properties and hydrodynamic properties of the resulting growth can be fine-tuned to match the required applications. [Formula: see text] electronics excitation was identified with small tunability of 487–500[Formula: see text]nm wavelength while the hydrodynamic size varied from 80–140[Formula: see text]nm with resulting pH range from 3.0–9.5 adjustable to appropriate applications, while the TEM results showed physical particle size of 1.7–3.7[Formula: see text]nm.

In this work, bismuth (Bi) and copper (Cu) doped lead lanthanum zirconate titanate (PLZT) 9/65/35 ceramics were fabricated by solid state sintering. Measurement of dielectric and ferroelectric properties at various temperatures was performed to determine electrocaloric effect in the ceramics. It was found that both undoped and doped PLZT ceramics exhibited relaxor behavior and phase transition from ferroelectric to relaxor. Indirect measurement of electrocaloric effect revealed that pure PLZT had broad peak of temperature change around the temperature at maximum dielectric constant and doped PLZT had narrower peak. Temperature change resulting from electrocaloric effect due to phase transition at low electric field could be observed in co-doped PLZT. It can be concluded that compositional effect played an important role to the change of dielectric, ferroelectric and electrocaloric properties because doping caused the change of electronic structure from A- and B-site substitution in perovskite structure of PLZT and the change of dynamic polar nanoregions.

A series of monometallic [Ln2(BDC)3(DMF)2(H2O)2]n (Ln = EuIII, GdIII, TbIII; H2BDC = benzene-1,4-dicarboxylic acid; DMF = dimethylformamide) and the lanthanide luminophores-loaded [LnxGd2-x(BDC)3(DMF)2(H2O)2]n (Ln = EuIII and TbIII) were synthesized and used in photoluminescent study. The dependence of emitting colors of [LnxGd2-x(BDC)3(DMF)2(H2O)2]n on the luminophore contents is reported and discussed based on the sensitization efficiency of BDC2− antenna. On the basis of an explicit change in the emitting colors of [EuxGd2-x(BDC)3(DMF)2(H2O)2]n, colorimetric analysis has been introduced as a new and effective strategy to establish ratiometric-thermometric parameters. Within the sRGB and CIE XYZ color matching systems, the temperature-dependent ratiometric-thermometric parameters could be derived from both x/(x+y) and R/(R+G) over 303–348 K covering physiological temperatures. Temperature resolution in term of standard deviation of the measurements, repeatability and relative sensitivity of the successive measurements have been evaluated and are reported.

The aim of this research is to investigate optical and photocatalytic properties of 0.25, 0.5 and 1.0 mol% BiVO4 doped bismuth silicate glasses. The glasses composition is 60 mol% SiO2 and 40 mol% Bi2O3. Optical spectra and the analysis of color by CIELab system revealed that the addition of BiVO4 changed the color of the glasses from pale yellow to yellow-orange with the narrower band gap. Photocatalytic activity was observed in 0.5 and 1.0 mol% BiVO4-doped glass. The effect of BiVO4 doping to bismuth silicate glass is also discussed.

Graphene Quantum dots (GQDs) are used as a surface-enhanced Raman substrate for detecting target molecules with large specific surface areas and more accessible edges to enhance the signal of target molecules. The electrochemical process is used to synthesize GQDs in the solution-based process from which the SERS signals were obtained from GQDs Raman spectra. In this work, GQDs were grown via the electrochemical process with citric acid and potassium chloride (KCl) electrolyte solution to obtain GQDs in a colloidal solution-based format. Then, GQDs were characterized by transmission electron microscope (TEM), Fourier-transform infrared spectroscopy (FTIR), and Raman spectroscopy, respectively. From the results, SERS signals had observed via GQDs spectra through the Raman spectra at D (1326 cm−1) and G (1584 cm−1), in which D intensity is defined as the presence of defects on GQDs and G is the sp2 orbital of carbon signal. The increasing concentration of KCl in the electrolyte solution for 0.15M to 0.60M demonstrated the increment of Raman intensity at the D peak of GQDs up to 100 over the D peak of graphite. This result reveals the potential feasibility of GQDs as SERS applications compared to graphite signals.

In this work, a multi-electron transporting layer (ETL) for efficient perovskite solar cells is investigated. The multi-ETL consists of five conditions including SnO2, SnO2/SnOx, TiO2, TiO2/SnO2, and TiO2/SnO2/SnOx. The best performance of PSC devices is found in the SnO2/SnOx double-layer and exhibits a power conversion efficiency equal to 18.39% higher than the device with a TiO2 single-layer of 14.57%. This enhancement in efficiency can be attributed to a decrease in charge transport resistance (Rct) and an increase in charge recombination resistance (Rrec). In addition, Rct and Rrec can be used to explain the comparable power conversion efficiency (PCE) between a PSC with a SnO2/SnOx double-layer and a PSC with a triple-layer, which is due to the compensation effect of Rct and Rrec parameters. Therefore, Rct and Rrec are good parameters to explain the efficiency enhancement in PSC. Thus, the Rct and Rrec from the electrochemical impedance spectroscopy (EIS) technique is an easy and alternative way to obtain information to understand and characterize the multi-ETL on PSC.

The aim of this paper was to study the electrical signal produced by the commercial piezoelectric buzzer by impact testing. The experiment varied external resistor, sphere weight, incident angle of...

In this study, the effect of Nb, Ta and Sb addition on the structure, dielectric and ferroelectric properties of the Pb(Zr0.5Ti0.5)O3 ceramics in the morphotropic phase boundary (MPB) region were investigated. Powders of pure PZT, PZT + 0.1 mol% Nb, PZT + 0.1mol% Ta and PZT + 0.1mol% Sb were synthesized by conventional mixed oxide method via a vibro-milling technique. All compositions of powders were uniaxially pressed in pellets and sintered at the temperature of 1275°C for 2h. Phase formation, dielectric and ferroelectric properties of ceramics were characterized by XRD, LCR meter and modified Sawyer–Tower Circuit respectively.

In this paper, 2-2 connectivity pattern lead-free piezoelectric ceramic Bi0.5Na0.5TiO3/Portland cement composites with ≈ 30–70 vol% of Bi0.5Na0.5TiO3 ceramic has been successfully fabricated. Dielectric and piezoelectric properties of the composites were investigated. The results showed that Bi0.5Na0.5TiO3 ceramic content has an effect on dielectric property of the composite, that is the dielectric constant value increased as Bi0.5Na0.5TiO3 ceramic content increased while the dielectric loss value reduced at higher Bi0.5Na0.5TiO3 ceramic content. The piezoelectric coefficient (d33) values of composites obtained were in the range of 48 pC/N to 73 pC/N. Moreover, composite with Bi0.5Na0.5TiO3 ceramic content of ≈ 30 vol% exhibited highest piezoelectric voltage coefficient (g33) value of 26.06 mV m/N. Therefore, these promising results showed that the 2–2 connectivity pattern lead-free piezoelectric ceramic Bi0.5Na0.5TiO3/Portland cement composite has the potential to be used as a sensor for structural health monitoring application.

The objectives of this research are to fabricate and investigate new smart composites for structural vibration control applications in concrete structure. The fabrication and properties of 0–3 cement pozzolan-based piezoelectric ceramic composites are emphasized. To this end, a novel approach to effectively improve the properties of cement by using pozzolanic materials and also improve poling of piezoelectric ceramic by adding a semiconductor was examined. In this research, silica fume (SF) and graphene nanoplatelets (GNPs) was chosen as a pozzolanic materials and a third phase with piezoelectric ceramic and Portland cement to produce new composites of ceramic-cement pozzolan-third phase combination. Microstructure of the new composites was investigated using Scanning electron microscope (SEM). The ferroelectric properties and dielectric permittivity were then investigated

This research focuses on optical properties of bismuth silicate based glasses. The glasses with the composition 60SiO2-40Bi2O3 were prepared and 3d transition metals (Cr, Mn, Fe, Co, Ni and Cu) with 0.1, 0.3, 0.5 and 1 at% were added. Optical spectra in terms of transmittance were used to analyze color shade with CIELab analysis in all glasses. Transmittance of glasses was changed in intensity and dominant wavelength when the transition metals were incorporated. This resulted in the change of lightness and color shade or CIELab values. Localization of 3d transition metals resulted in change of optical properties by non-bridging oxygen ions, which acted as network modifier.

Lead iron niobate (PFN) has been reported as a high dielectric ceramic. However, the fabrication of PFN to obtain high purity needs careful preparation and complex techniques. In this study, lead zirconate titanate (PZT) was added to PFN to produce (1-x)PFN–xPZT composites where x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5. The X-ray diffraction (XRD) patterns confirmed that all ceramics had perovskite structure with Pb2FeNbO6 as a second phase when x = 0 and 0.1. Pure PFN could be obtained in the form of PFN–PZT composites with PZT when x = 0.2–0.5. Dielectric behavior of PFN showed relaxor ferroelectric behavior as broad dielectric peak could be observed. The temperature at the maximum dielectric constant increased when PZT was added to PFN ceramics. The change of the degree of diffuseness, the variation of Curie-Weiss behavior and the broadness of dielectric peaks confirmed that the dielectric behavior was less relaxor and more normal ferroelectric when the amount of PZT was increased. Electrical conductivity of PFN–PZT composites was also discussed to explain the change of ferroelectric behavior in relation to the activation energy required for charge hopping process.

The 0–3 connectivity piezoelectric ceramic-cement composites of barium zirconate titanate (BaZr0.05Ti0.95O3, BZT) and Portland cement were developed for smart concrete structure applications. In th...

Lead lanthanum zirconate titanate ceramics (PLZT) are well known for their excellent dielectric, piezoelectric and ferroelectric properties. In this study, PLZT 9/70/30, 9/65/35 and 9/60/40 ceramics were prepared by vibro-milling mixed-oxide method. All compositions of powders were uniaxial pressed in pellets and sintered at the temperatures of 1200–1275 °C with various soaking times of 2, 4 and 6 h. The X-ray diffraction (XRD) patterns confirmed that all the PLZT samples had perovskite structure with ZrO2 as a second phase and PLZT/ZrO2 composite structure was formed. Dielectric behavior at the frequency of 1 kHz showed broad peak indicating relaxor ferroelectric behavior and the difference of the temperature at maximum dielectric at different frequencies increased when Zr:Ti ratio increased. Polarization with electric field (P-E loop) at room temperature showed that when Zr:Ti ratio increased, the coercive field decreased resulting from crystal structure change from tetragonal to rhombohedral. Induced strain with electric field depended on microstructure where the value of Smax/Emax tended to decrease with increasing grain size. It can be concluded that dielectric and ferroelectric behavior predominantly depended on composition of PLZT ceramics and induced strain behavior predominantly depended on grain size of PLZT ceramics.

The isostructural [Ln(L)0.5(NO2-BDC)(H2O)]·3H2O complexes (Ln = EuIII (I), TbIII (II), GdIII (III) and 0.012EuIII/0.494TbIII/0.494GdIII (IV); L = BDC2− or BDC2−/NO2-BDC2−; H2BDC = 1,4-benzenedicarboxylic acid) were synthesized and characterized by powder X-ray diffraction and wavelength dispersive X-ray fluorescence. Room temperature and temperature dependent photoluminescence behavior of the title complexes were studied in solid state using the ground crystals. The rare constant intensity of EuIII with increasing temperatures in complex I is reported, and a potential of the mixed complex IV as a ratiometric luminescence thermometer in a temperature range 333(2)–423(2) K is illustrated.

In this work, Pb0.91La0.09(Zr1–xTix)0.9775O3 ceramics where x = 0.3, 0.35 and 0.4 (the composition near MPB) were prepared by solid solution method. After fabrication process, electrical property w...

Piezoelectric ceramic – Portland cement composites have been developed for sensor application in concrete structures to overcome the acoustic matching problem that may occur for piezoelectric ceramic or polymers with concrete. Pozzolanic materials such as fly ash are commonly used in concrete to enhance durability. The objectives of this research were to investigate the effects of fly ash addition on the physical properties, dielectric properties and piezoelectric properties of 0–3 barium zirconate titanate ceramic– Portland cement composites. The results showed that the dielectric constant of these composites decreased when the fly ash content in the composite increases. However , the piezoelectric coefficient (d 33 ) value of BZT–PC composite with fly ash 10% by volume was found to be similar to that of BZT–PC composites.

Photoplethysmography (PPG) is one of the optical signals commonly used in clinical research for measuring the vital signs. Previously, PPG is often used as an indicator for detecting blood volume changes in the micro-vascular. The advantages of PPG signal mentioned in studies are non-invasive, lower operation cost, and the simplicity of the procedure. Although some the components of the PPG signal are not fully understood, it is generally accepted that it can provide valuable information in clinical study. Thus, it is interesting for finding a relation between PPG signal and blood alcohol concentration. The objective of this study is to classify two groups of ten-volunteer: (1) group of people who consumed alcohol and (2) non-consumed alcohol, by using the difference of PPG signals in these two groups and compared the results with fuel-cell breath alcohol analyzer. A set of PPG reflection data is recorded from optical sensors including the wavelength light of the red light and the infrared light from the fingertip of individuals. In additional, the changes of each signals for distinguishing two groups of volunteers are examined. The set of data is computed and analysed to find the correlation coefficient between significant variables in statistic domain. The analysis techniques are included (1) slope of the signals over time, (2) peak to peak of the heart rate, and (3) deep of waveform valley after rotation for training generalized linear (GLM) classifiers to create classification models. The accuracy of GLM classification can be obtained up to 87.50%. This suggests that PPG technique with our lab prototype has a potential for screening test to classify people who consumed alcohol and non-consumed alcohol.

PVDF-modified 0–3 connectivity cement-based/lead-free 0.94(Bi0.5Na0.5)TiO3–0.06BaTiO3 piezoelectric ceramic composites were fabricated using 0.94(Bi0.5Na0.5)TiO3–0.06BaTiO3 (BNBT), Portland cement, and polyvinylidene fluoride (PVDF). The microstructure, acoustic impedance (Z c), dielectric properties, and influence of poling temperature and electrical poling field on the piezoelectric coefficient (d 33) and the total period of the poling process of composites with 50 vol% BNBT and 1–10 vol% PVDF were investigated. The results indicated that Z c, the dielectric constant, and the dielectric loss of the composites decrease as the PVDF content increases. The d 33 of the composites was found to enhance more clearly when the content of PVDF is more than 2 vol%. The d 33 results of the composites showed an optimum increase of 45% when 5 vol% PVDF was used (under an electrical poling field of 1.5 kV/mm and a poling temperature of 80°C). Moreover, these composites with PVDF were found to exhibit enhanced poling behavior in that the PVDF was able to reduce the total period of the poling process. Interestingly, the piezoelectric voltage coefficient (g 33) of the composite with 5 vol% PVDF content had the highest value of 33.59 mV·m/N. Therefore, it can be safely concluded that this new kind of PVDF-modified 0–3 connectivity cement-based/lead-free 0.94(Bi0.5Na0.5)TiO3–0.06BaTiO3 piezoelectric ceramic composite has the potential to be used in concrete as a sensor for structural health monitoring applications.

Lead-free bismuth sodium titanate-bismuth potassium titanate-barium titanate ceramic/cement composites with carbon nanotubes (CNTs) addition were developed for smart structures application. The pores in composite and insulating nature of the cement matrix made the poling difficult and lower piezoelectric activities of composites. In this work, CNTs additions as a conducting phase at 0–2% by volume was mixed with ceramic and Portland cement by pressing and curing method. The influence and optimum of CNTs content on the microstructure, dielectric, electrical conductivity, acoustic impedance and piezoelectric properties of composites were studied. The results indicate that the CNTs are filled in the pores between the hydration products of cement as observed using scanning electron microscope. The highest piezoelectric coefficient ( d 33 ) and piezoelectric voltage coefficient ( g 33 ) values of composite with CNTs content was found at 1% by volume where the values are 58 pC/N and 30.20 × 10 −3 Vm/N, respectively. Therefore, CNTs content at 1% by volume was optimum for improvement of the piezoelectric properties for cement based-ceramic composites. All composites with CNTs content in the range tested were found to have good compatibility with concrete structure with matching acoustic properties.

The 0-3 lead-free bismuth sodium titanate-bismuth potassium titanate-barium titanate (BNBK) ceramic/Portland cement composites (PC) were fabricated by pressing and curing method. The influence of BNBK particle size on the dielectric and acoustic properties of 0-3 BNBK-PC composites was studied. BNBK of various median particle sizes (75, 212 and 425 μm) at 50% by volume were mixed with Portland cement to produce the 0-3 BNBK-PC composites. The dielectric constant results of composites were found to increase with increasing BNBK particle size and the dielectric constant of composite with 425 μm particle size at 1 kHz was 196. The 0-3 BNBK-PC composites in the range tested have an acoustic impedance match with concrete structure.

The 1–3 connectivity lead-free piezoelectric composites were produced from the bismuth sodium titanate-bismuth potassium titanate-barium titanate (BNBK) ceramic and Portland cement (PC) by dice-and-fill method. Microstructure and performance of composites were investigated and compared with predicted models. The results indicated that the BNBK ceramic can improve the dielectric, piezoelectric coefficient and thickness electromechanical coupling coefficient properties in composites. At ≈40% BNBK ceramic content is the optimal BNBK content for an acoustic impedance match between composites and concrete. The dielectric constant and piezoelectric coefficient were close to the parallel model. The piezoelectric voltage coefficient of all composites was found to be higher than pure ceramic and the g33 value were found to be 26.55 × 10−3 Vm/N and 21.74 × 10−3 Vm/N for composite with 30% and 70% BNBK contents, respectively. The 1–3 BNBK-PC composites have good compatibility with concrete obtaining good performance for use in smart structures applications.

In the present study, lead-lanthanum-zirconate-titanate (PLZT) ceramics were prepared by a solid-state mixed oxide method. Different amount of lithium carbonate and bismuth oxide (0.15 mol%, 0.45 mol% and 0.75 mol%), where the ratio of Li:Bi =1:1 by mole, was added to PLZT to investigate the effect of Li and Bi co-doping. The ceramic samples were sintered at the temperatures of 1000, 1050, 1100, 1150 and 1200 °C for 4 h. After that, all samples were subjected to phase identification, physical property determination (sintered density and microstructure) and dielectric property measurement. It was found that doping of 0.15 mol% Li and Bi resulted in maximum dielectric constant (e r =7819) when sintered at 1200 °C. Grain size of PLZT ceramics was dependent on sintering temperature and dielectric properties were affected by the chemical composition rather than the grain size of the ceramics. Therefore, co-doping of Li and Bi was useful as it could improve the dielectric properties of PLZT ceramics.

The new nanoporous framework [Gd4(di-nitro-BPDC)4(NO2)3(OH)(H2O)5]·(solvent) (I; di-nitro-BPDC2– = 2,2′-dinitrobiphenyl-4,4′-dicarboxylate) has been designed and synthesized through a simple one-po...

A new series of non-porous, three-dimensional coordination frameworks, i.e. [LnIII(bdc)0.5(phth)(H2O)2], where LnIII = EuIII, TbIII, HoIII, ErIII and TmIII, phth2- = 1,2-benzenedicarboxylate, and bdc2- = 1,4-benzenedicarboxylate, were synthesized and characterized. The frameworks have two-dimensional sheets of which the stoichiometry is the same as the framework containing only phth2-. Architecture, topology and thermal stability of the frameworks were examined. Temperature-dependent photoluminescent properties of the EuIII and TbIII frameworks were studied and discussed with reference to those containing only phth2- and bdc2-. The mixed EuIII/TbIII frameworks were also prepared and their temperature-dependent photoluminescent properties were investigated, revealing energy transfer from TbIII to EuIII and its dependence on EuIII content.

This research involves an application of reflection photoelasticity used to analyze stressed samples. The poly(methyl methacrylate) (PMMA) had a rectangular shape 2.5 × 2.5 × 0.6 cm and was compressed by hydraulic press system. The observation of a stressed sample using reflection photoelasticity showed isochromatic and isoclinic fringe patterns. We adjusted the polariscope to determine the photoelastic parameters, namely fringe order, angle principal stress and strain value, which were used to calculate the stress-strain based on calibration, shear difference method and stress-strain optic law. It was found that maximum normal stress (y-direction) and strain values were at contact area and decreased to the edge and center along horizontal and vertical direction of sample. Shear stress depended on multiple of fringe order and sin 2 θ . It was zero along center of vertical and horizontal direction of sample.

PbZr1-xTixO3 (PZT) powders (x = 0.45–0.54) were synthesized by conventional solid state reaction method. The phase information was investigated by a combination of X-ray diffraction and X-ray absorption spectroscopy (XAS) techniques. The XRD measurements indicated the global phase formation of the prepared powders was the mixture of rhombohedral and tetragonal phases. However, the local phase formation around titanium atom was revealed using X-ray Absorption Near-Edge Structure (XANES), indicating the existence of monoclinic phase within the compositional range studied.

In this paper, the 2-2 parallel connectivity barium titanate (BT) piezoelectric ceramics and Portland cement (PC) were fabricated by dice-and-fill method. The acoustic impedance (Zc) and electromechanical coupling coefficient (Kt) of composites were experimentally investigated as a function of BT ceramic content. When BT ceramic content increases from 30 to 70 vol%, Zc values increases from 8.51 to 14.32 kg⋅m−2s−1. According to the results, the composites with BT ceramic content of 30 to 50 vol% showed Zc values matching with concrete materials. In addition, with the optimum BT ceramic content of 30 to 50 vol% where the Kt values of composites were 17.31 to 19.59%. These composites therefore have promising characteristics for potential use as smart materials for structural health monitoring applications in concrete structures.

Hybrid-doped BaTiO3 ferroelectric polycrystalline ceramic samples were synthesized by solid state reaction. The concentration of La3+ was fixed 1 mol% while that of Sm3+ varied from 1 to 4 mol%. The effect of the replacement, which can be either lanthanum or samarium, in a cationic site on structural and physical properties of BaTiO3 was investigated. The dielectric permittivity changed significantly with temperature in a wide temperature rang. It was found that the dielectric behavior can be ascribed to the change in defect concentrations in different lattice locations in BaTiO3 structure.

The ferroelectric materials with high Curie temperature in (1-x)[0.5Bi(Zn0.5Ti0.5)O3− 0.5PbTiO3]−(x)[(Bi0.5K0.5)TiO3] or (1-x)[0.5BZT−0.5PT]−(x)BKT ternary system were synthesized by solid state reaction technique. The single phase perovskite was formed at 950°C in compositions with x ≥ 0.50. The dielectric properties (ϵr and tan δ) were observed to exhibit the relaxor-like behavior. From room temperature P–E measurement, both Pr and Ec were found to increase with increasing BKT content.

In this work, Pb 0.91 La 0.09 (Zr x Ti 1−x ) 0.9775 O 3 PLZT ceramics, where x =0.70, 0.65 and 0.60, were prepared by a solid-state mixed-oxide technique. Structural information was investigated by X-ray diffraction method. Electric field induced polarization and strain behavior of the PLZT ceramics under an influence of static magnetic field were measured by a Sawyer-Tower circuit in conjunction with Michelson interferometer at various static magnetic fields (0–30.7 mT). The results showed that the imposed magnetic field affected the polarization and induced strain behaviors in PLZT ceramics More interestingly, the imposed magnetic field showed more significant influence on the PLZT ceramic composition near morphotropic phase boundary (MPB), i.e. PLZT 9/65/35. The spontaneous polarization of 180° domain switching was seen to be suppressed by the applied magnetic field.

In this study, the fringe pattern distribution of various loads on circular disk of homogeneous acrylic in different thicknesses by using reflection polariscope technique was carried out. The load was pressed at the top and the bottom to produce the fringe patterns, which were recorded by digital camera. Then the results were analyzed. The number of isochromatic fringe pattern depends on the magnitude of force acting on the circular disk and these relation is linearly. The application of these research is used to predict stress distribution on the transparent material in the case of different dimension of the circular disk shape.

PLZT 9/65/35 (Pb0.91La0.09(Zr0.65Ti0.35)0.9775O3) ceramics with addition of 0.25, 0.5 and 1.0 wt% of Bi2O3/CuO (where the ratio of Bi2O3:CuO=9:1 by mole) were prepared by sintering at the temperatures between 1000 and 1200 °C. It was found that Bi2O3/CuO could bring the sintering temperature down ~50 °C to obtain PLZT with no second phase. Dielectric and ferroelectric properties were investigated. Bi2O3/CuO decreased both coercive field and remnant polarization, which was caused by an increase of the degree of diffuseness in relaxor ferroelectric materials. Electric field induced strain behavior was also investigated and it was found that the addition of Bi2O3/CuO increased the maximum induced strain and maximized electrostrictive effect. Therefore, Bi2O3/CuO was useful as a sintering aid, which improved the dielectric and the relaxor ferroelectric properties as well as the electric field induced strain of PLZT ceramics.

The optical spectroscopic properties of fluorescent materials were investigated using laser induced fluorescence technique. The fluorescent creams were used in this research. The sample materials were illuminated by UV laser excitation source. Then, the fluorescence spectra were recorded and analyzed by fiber optics spectrometer complied with the CIE 1931 XYZ color space which is essential for color management. The result showed that the characteristics of fluorescence spectra such as intensity, wavelength position and bandwidth in each fluorescent creams exhibited distinct characteristics in each species.

In this work, (1−x)Pb(Mg1/3Nb2/3)O3−xPbTiO3 (PMN−PT) where x = 0.1−0.3 relaxor ferroelectric ceramics were prepared. PMN−PT ceramics were subjected to measurement of dielectric constant by LCR meter by cooling method from 200 to 25°C and investigation subswitching electric field induced strain behaviour was carried out twice, before and after 500°C annealing, by modified Michelson interferometric technique at various temperatures (30−70°C). The result showed higher dielectric properties and broad peak at phase transition temperature Tm of ferroelectric to paraelectric, like the nonlinear change of integrated P-E areas and s-E areas around 40 and 90°C for x = 0.1 and 0.2, but the induced strain and integrated s-E area are very sensitive to the annealing effect to observed ferroelectric phase change from normal ferroelectric to relaxor phase around 40 and 60°C for x = 0.2 and 0.3.