CaCO3 Precursor Research Articles

In Situ Monitoring the Nucleation and Growth of Nanoscale CaCO3 at the Oil-Water Interface.

Interfaces can actively control the nucleation kinetics, orientations, and polymorphs of calcium carbonate (CaCO3). Prior studies have revealed that CaCO3 formation can be affected by the interplay between chemical functional moieties on solid-liquid or air-liquid interfaces as well as CaCO3's precursors and facets. Yet little is known about the roles of a liquid-liquid interface, specifically an oil-liquid interface, in directing CaCO3 mineralization which are common in natural and engineered systems. Here, by using in situ X-ray scattering techniques to locate a meniscus formed between water and a representative oil, isooctane, we successfully monitored CaCO3 formation at the pliable isooctane-water interface and systematically investigated the pivotal roles of the interface in the formation of CaCO3 (i.e., particle size, its spatial distribution with respect to the interface, and its mineral phase). Different from bulk solution, ∼5 nm CaCO3 nanoparticles form at the isooctane-water interface. They stably exist for a long time (36 h), which can result from interface-stabilized dehydrated prenucleation clusters of CaCO3. There is a clear tendency for enhanced amounts and faster crystallization of CaCO3 at locations closer to isooctane, which is attributed to a higher pH and an easier dehydration environment created by the interface and oil. Our study provides insights into CaCO3 nucleation at an oil-water interface, which can deepen our understanding of pliable interfaces interacting with CaCO3 and benefit mineral scaling control during energy-related subsurface operation.

Exploring the role of surface and porosity in CO2 capture by CaO-based adsorbents through response surface methodology (RSM) and artificial neural networks (ANN)

In this study, synthetic CaCO3 materials were utilized as precursors for CaO-based CO2 sorbents. The investigation examined how various operating parameters—such as synthesis temperature (ST), stirring rate (SR), and surfactant percentage (SP)—impact the properties of the adsorbents. Samples were firstly characterized by X-ray diffraction and Scanning Electron Microscopy (SEM), which revealed that the prevalence of calcite or aragonite crystal phases in the synthetic CaCO3 precursors can be tuned by adequately choosing the dose of surfactant (Triton-X100®), so that it can be used as a crystal habit and growth modifier. The calcination process applied to the CaCO3 precursors leads to the formation of partially sinterized cubic crystals of CaO, accompanied by minor quantities (< 5 %) of additional compounds like Ca(OH)2 or CaSO4. Specific surface area (SBET) and porosity were determined by measuring the N2 adsorption isotherms. A CaCO3 sample with an unprecedented value of SBET as large as 116 m2/g was prepared operating under optimal conditions. SBET and pore volumes were successfully correlated with the CO2 uptake capacity of the samples. SBET is more influential for experiments carried out under diluted CO2 atmosphere. When pure CO2 is used, the influence of meso- and micropore volumes (Vme and Vmi) is clearly predominant, which suggests that in this latter case diffusion through the porous texture of the samples plays a more remarkable role. A double-way approach through Response Surface Methodology (RSM) and the use of Artificial Neural Networks (ANNs) has been used to analyze the CO2 uptake capacity of the samples. Within the operational interval, excellent results were obtained for pure and diluted CO2 flow, and RSM and ANNs have demonstrated to be a very efficient tool to correlate the behavior of the CaO-based materials as CO2 sorbents with the surface area and pore volumes of the samples. Valuable information on (i) the importance of the different factors under study; (ii) their influence on the surface and porosity of the CaO-derived sorbents; and (iii) the subsequent CO2 capture performance of the sorbents has been obtained. The results suggest that four parameters have a statistically significant influence on CO2 uptake. These parameters are SR, the square of SR, its interaction with SP, and the square of SP. Additionally, the study assessed the stability of the CaO-based sorbents over 11 consecutive calcination-carbonation cycles. By adequately choosing the synthesis strategy and conditions, an almost negligible shrinkage effect can be achieved, resulting in a more sustained uptake capacity throughout the cycles.

Micro-structural, thermal, and optical properties of nanostructured CaMoO4 materials screened under different processes

In this work, we have varied numerous conditions to obtain nanocrystalline CaMoO4 materials by high-energy-ball-milling, mechanical stirring, and wet chemical methods. Despite several conditions suited for the formation of scheelite CaMoO4 phase, interestingly mechanical stirring of CaCO3 and MoO3 precursors with deionized water yielded pure tetragonal CaMoO4 phase in a simple way. All the processed CaMoO4 materials show rather broad reflections with reduced average crystalline size (14.2 ∼ 26.6 nm). The thermal profiles of phase pure CaMoO4 materials show relatively low weight loss as compared to contaminated samples signifying the formation of the CaMoO4 phase. The calculated optical band gap for the CaMoO4 samples is in the range of 3.55–3.93 eV. While the high-energy-ball-milling method prepared CaMoO4 materials exhibit lower NIR reflectance values, the wet chemical synthesized CaMoO4 materials reveal quite higher NIR reflectance in the region (750–2500 nm). The Raman spectral analyses well support the optical properties of the CaMoO4 phase. Agglomerated nature of round-shaped particles is seen for the co-precipitation and ball-milled processed CaMoO4 materials.

Process-Specific Effects of Sulfate on CaCO3 Formation in Environmentally Relevant Systems.

Additives, such as ions, small molecules, and macromolecules, have been found to regulate the formation of CaCO3 and control its morphologies and properties. However, a single additive usually affects dominantly one process in CaCO3's formation and is seldom found to significantly affect multiple CaCO3 formation processes. Here, we used in situ grazing incidence X-ray techniques to observe the heterogeneous formation of CaCO3 and found that a series of formation processes (i.e., nucleation, growth, and Ostwald ripening) were modulated by sulfate. In the nucleation process, increased interfacial free energy and bulk free energy cooperatively increased the nucleation barrier and decreased nucleation rates. In the growth process, sulfate reduced the electrostatic repulsion between CaCO3 precursors and nuclei, promoting CaCO3 growth. This influence on the growth counteracted the inhibition effect in the nucleation process, causing a nearly 100% increase in the volume of heterogeneously formed CaCO3. Meanwhile, adsorbed sulfate on CaCO3 nuclei may poison the surface of smaller CaCO3 nuclei, inhibiting Ostwald ripening. These revealed sulfate's active roles in controlling CaCO3 formation advance our understanding of sulfate-incorporated biomineralization and scaling phenomena in natural and engineered aquatic environments.

Decay on Cyclic CO2 Capture Performance of Calcium-Based Sorbents Derived from Wasted Precursors in Multicycles

In order to obtain the cheap waste calcium-based sorbent, three wasted CaCO3 precursors, namely carbide slag, chicken eggshells, and analytical reagent-grade calcium carbonate, were selected and prepared at 700 °C to form calcium-based sorbents for CO2 capture. TGA was used to test the CO2 uptake performance of each calcium-based sorbent in 20 cycles. To identify the decay mechanism of CO2 uptake with an increasing number of cycles, all calcium-based sorbents were characterized by using XRF, XRD, and N2 adsorption. The specific surface area of calcium-based sorbents was used to redefine the formula of cyclic carbonation reactivity decay. The carbonation conversion rate of three calcium-based sorbents exhibited a decreasing trend as the cycle number increased. Chicken eggshells exhibited the most significant decrease rate (over 50% compared with Cycle 1), while carbide slag and analytical reagent-grade calcium carbonate showed a flat linear decline trend. The specific surface area of the samples was used to calculate carbonation conversion for an infinite number of cycles. The carbonation conversion rates of three calcium-based sorbents were estimated to decrease to 0.2898, 0.1455, and 0.3438 mol/mol, respectively, after 100 cycles.

Economical and Environmentally Friendly Track of Biowaste Recycling of Scallop Shells to Calcium Lactate.

The scallop shell waste (Pectinidae, one of saltwater clams) was used as a raw material (precursor) to prepare calcium lactate (Ca(C2H4OHCOO)2), and the physicochemical properties of scallop-derived calcium lactate were then investigated. The scallop waste was first ground to obtain calcium carbonate (CaCO3) powder, and the calcium lactate compounds were successfully synthesized by the reactions between shell-derived CaCO3 and lactic acid (C2H4OHCOOH). The short preparation time, high percentage yield, and low-cost production are the preferred manners, and, in this research, it was the reaction of 70 wt % lactic acid and scallop-derived CaCO3. The thermal decompositions of both CaCO3 precursor and all prepared calcium lactates resulted in the formation of calcium oxide (CaO), which is widely used as a catalyst for biodiesel production. By comparing with the literature, the results obtained from the characterization instruments (infrared spectrophotometer, X-ray diffractometer, thermogravimetric analyzer, and scanning electron microscope) confirmed the formation and crystal structure of both CaCO3 and its calcium lactate product. The morphologies of calcium lactate show different sizes depending on the acid concentration used in the reaction process. Consequently, this work reports an easy, uncomplicated, low-cost technique to change the cheap calcium compound product (scallop CaCO3) derived from shellfish waste to the valuable compound (calcium lactate), which can be used in many industries.

Synthesis of Egyptian Blue and mechanisms

Egyptian Blue (EB, Cuprorivaite, CaCuSi4O10) is a novel candidate for nanomaterial-based sensors in water, as its infrared (IR, 910 nm) emission has high quantum yield in comparison with current commonly-used IR reporters. IR signals for bioimaging and environmental sensing penetrate biological matrices (i.e. tissues) deeper and with less scattering than visible light. This work reports the effects of heating rate on the solid state synthetic yield of EB and formation mechanism is discussed. EB synthesis was investigated with thermogravimetric analysis coupled with mass spectrometry and in-situ high temperature X-ray diffraction. A reproducible maximum in EB yield was observed at a heating rate of 7 °C/min with samples containing CaCO3 precursor. We report the optimized reaction conditions, yields, and the photoluminescent response of the synthesized EB layered materials. The precursor content (O2, CaCO3, CuO and SiO2) also had a subtle effect on EB yield.

Examining the Ability of Aerobic Halophilic Heterotrophic Microbial Consortia to Replace Ca by Mg in Different CaCO3 Precursors.

Recent laboratory experiments have exhibited microbes as promising agents in solving the perplexing origin of ancient dolomite by demonstrating microbial capability to mediate dolomite nucleation and growth. However, dolomite crystals from laboratory experiments have shown irrelevant characteristics to ancient dolomite from mineralogical and petrological perspectives. A major irrelevant characteristic is that ancient dolomite was assumed to be formed after the replacement of Ca by Mg in precursor CaCO3 in a process known as diagenesis, which contrasts with the primary precipitation process observed in laboratory culturing experiments. Considering dolomite microbial experiments, one can imply the involvement of microbes in the formation of ancient dolomite, as microbes have shown the ability to overcome the dolomite kinetic barrier. Despite that fact, the ability of microbes in mediating dolomite diagenesis has not been investigated. In this study, microbes were applied to mediate replacement of Ca by Mg in different CaCO3 precursors. The microbial replacement experiments were based on the enrichment of aerobic halophilic heterotrophic microbial consortia sampled from sediments collected from Al-Subiya sabkha in Kuwait. Two experiments were performed in saturated media at 35°C for 14 and 30 days simulating the conditions of microbial dolomite experiments. The change in mineralogy was examined via powder X-ray diffraction (XRD), and the change in texture and compositional microstructures was examined using scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). The effect of microbes on the alteration of CaCO3 precursors was studied by comparing biotic experimentations with abiotic controls. The biotic samples were shown to result in the favorable conditions for dolomite formation including an increase in pH and alkalinity, but no changes were observed in mineralogy or compositional microstructure of CaCO3 precursors. Our results suggest the inability of aerobic halophilic heterotrophic microbial consortia to introduce Mg replacement on CaCO3 precursors in a timely manner that is comparable to primary precipitation in microbial dolomite experiments. The inability of the enriched microbial consortia to mediate replacement can be ascribed to different factors controlling the diagenetic process compared to primary precipitation in microbial dolomite experiments.

Influence of additives on CaCO3 precursors and multicycle CO2 capture performance of CaO sorbents

Calcium looping based on alternation between uptake and release of CO2 is a promising technology for high-temperature CO2 capture. In this study, CaO sorbents were obtained from different precipitated CaCO3 precursors. Two additives, cetyltrimethyl ammonium bromide (CTAB) and triblock copolymer (P123), were used to modify CaCO3 precursors. Physical properties (morphology, crystal structure and porosity) of CaCO3 precursors, as well as CO2 capture performance of CaO sorbents were investigated. It was found that the presence of different concentration of additive would affect crystal composition and porosity of CaCO3 precursor. Experimental data showed that CaO sorbents derived from CaCO3 modified with 8 mmol/L CTAB exhibited higher CO2 capture capacity than other CaO sorbents after multiple cycles. Furthermore, the relationship between CO2 capture performance and properties of CaCO3 precursors was established. BET surface area and pore volume of CaCO3 precursors were positive correlated to average carbonation conversion. For CTAB cases, molar ratio of vaterite to calcite was negatively correlated to average carbonation conversion; and for P123 cases, molar ratio of vaterite to calcite was positively correlated to average conversion.

Immobilization and migration of arsenic during the conversion of microbially induced calcium carbonate to hydroxylapatite

Coprecipitation with calcium carbonate (CaCO3) could decrease the bioavailability of arsenic (As). However, in a phosphate-rich environment, some CaCO3 will be converted to hydroxylapatite (HAP). Currently, the behavior of carbonate-bound As during conversion is unclear. Therefore, we prepared bio-induced CaCO3 in an As solution and converted it to HAP. The results showed that a high concentration of arsenate promoted vaterite precipitation and the conversion of CaCO3 to HAP. The dissolution data verified the low solubility of As in HAP, though its As-bearing CaCO3 precursor released up to 88.19% As during the conversion. Furthermore, HPLC-ICP-MS data showed partial oxidation of arsenite to arsenate, suggesting that CaCO3 and HAP's structure favored the incorporation of arsenate. Our results demonstrated that the stability of heavy metal-bearing CaCO3 should be considered, and the role of HAP in the immobilization of heavy metals such as As should not be overestimated.

Precipitation of Calcium Carbonate Inside Giant Unilamellar Vesicles Composed of Fluid-Phase Lipids.

Biomineralization of CaCO3 commonly involves the formation of amorphous CaCO3 precursor particles that are produced in a confined space surrounded by a lipid bilayer. While the influence of confinement itself has been investigated with different model systems, the impact of an enclosing continuous lipid bilayer on CaCO3 formation in a confined space is still poorly understood as appropriate model systems are rare. Here, we present a new versatile method based on droplet-based microfluidics to produce fluid-phase giant unilamellar vesicles (GUVs) in the presence of high CaCl2 concentrations. These GUVs can be readily investigated by means of confocal laser scanning microscopy in combination with bright-field microscopy, demonstrating that the formed CaCO3 particles are in conformal contact with the fluid-phase lipid bilayer and thus suggesting a strong interaction between the particle and the membrane. Atomic force microscopy adhesion studies with membrane-coated spheres on different CaCO3 crystals corroborated this notion of a strong interaction between the lipids and CaCO3.

Synthesis and Characterization of Spherical Calcium Carbonate Nanoparticles Derived from Cockle Shells

Cockle shells are a natural reservoir of calcium carbonate (CaCO3), which is widely used in bone repair, tissue scaffolds, and the development of advanced drug delivery systems. Although many studies report on the preparation of CaCO3, the development of a nanosized spherical CaCO3 precursor for calcium oxide (CaO) that is suitable to be incorporated in dental material was scarce. Therefore, this study aimed to synthesize a nanosized spherical CaCO3 precursor for CaO derived from cockle shells using a sol–gel method. Cockle shells were crushed to powder form and mixed with hydrochloric acid, forming calcium chloride (CaCl2). Potassium carbonate (K2CO3) was then fed to the diluted CaCl2 to obtain CaCO3. The effect of experimental parameters on the morphology of CaCO3, such as volume of water, type of solvents, feeding rate of K2CO3, and drying method, were investigated using field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffractometry (XRD), Brunauer–Emmett–Teller surface area analysis, and thermogravimetric analysis. Optimized CaCO3 was then calcined to form CaO. XRD analysis of CaCO3 nanoparticles was indicative of the formation of a calcite phase. The well-structured spherical shape of CaCO3 was obtained by the optimum condition of the addition of 50 mL of water into CaCl2 in ethanolic solution with a 1 h feeding rate of K2CO3. Less agglomeration of CaCO3 was obtained using a freeze-drying technique with the surface area of 26 m2/g and average particle size of 39 nm. Spherical shaped nanosized CaO (22–70 nm) was also synthesized. The reproducibility, low cost, and simplicity of the method suggest its potential applications in the large-scale synthesis of the nanoparticles, with spherical morphology in an industrial setting.

Sol-gel synthesis and solar photocatalytic activity of Ca-alloyed ZnO nanoparticles elaborated using different precursors.

Ca-alloyed ZnO nanoparticles elaborated using different calcium precursors (CaSO4, CaCl2, Ca(NO3)2 and CaCO3) at different [Ca]/[Zn] ratios (0, 1, 5, 10, 15 and 20%) have been prepared by a sol–gel method followed by supercritical drying and annealing at 300 °C. The synthesized samples have been characterized by a number of techniques including Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray Diffraction (XRD), Raman Spectroscopy and Electron Paramagnetic Resonance (EPR). SEM and TEM images reveal that the nanoparticles have a quasi-spherical shape with a grain size between 20 and 40 nm. The EDS results on chemical elementary compositions show that the Ca-alloyed ZnO with a CaCO3 precursor and [Ca]/[Zn] ratios of 5 and 10% are quasi-stoichiometric. The XRD results indicate that all the elaborated nanoparticles have a hexagonal wurtzite structure. Using Raman Spectroscopy a supplementary vibrational mode is detected in the case of CaSO4, CaCO3 and Ca(NO3)2 precursors. The intrinsic defect centers and defect number have been studied using EPR. Two intrinsic defects with different g factors are identified by EPR for which the spectral intensities change with calcium precursors. Furthermore, EPR reveals a correlation between the defect number and photocatalytic efficiency. The photocatalytic efficiency of the nanoparticles elaborated with different precursors and compositions has been studied for the solar photocatalytic degradation of pyrimethanil, using a solar simulator. The results show that the nanoparticles of Ca-alloyed ZnO elaborated with a CaCO3 precursor give promising results and enhance the photocatalytic efficiency in the solar field.

Intrashell Variability of Trace Elements in Benthic Foraminifera Grown Under High CO2 Levels

Two species of Amphistegina were cultured under four variable DIC concentrations (2340–2570 μM). The variability of trace elements within the foraminiferal shells was measured in the knob area of three individuals for each DIC treatment using LA-ICPMS. In individuals that showed significant growth (identified via 135Ba-enriched seawater), B, Na, and Sr showed an increase with DIC, while K and Mg were slightly lower or unchanged. Sharp transition zones between natural 135Ba and the ∼10-fold increased 135Ba in the shells represent one quarter of a new additional chamber, which occurs roughly once a week. The shape of the transition zone is best described by a logistic equation for population growth. We propose that this reflects the dynamics of seawater vacuoles that serve the biomineralization process and provide Ca and DIC for calcification of Amphistegina as described in previous publications (e.g., Bentov et al., 2009). LA-ICPMS profiles in the central knob (∼70 μm depth) also revealed previously described cyclical changes in concentration of Mg, each apparently representing a growth of a new chamber. Additional elements such as K, Na and U showed similar cycles with the same frequency and phase as the Mg cycles. Sr showed variability with similar frequency but not in-phase to those of the Mg. These multi-element cycles were found both in the newly grown calcite (elevated-135Ba) and in the natural skeleton regardless of the DIC treatments. These high Mg and multi-element cycles seem to be an essential part of the calcification process. They may originate from the interaction with the organic matrix resulting in elevated Mg and other elements in primary calcite while secondary calcite of the lamination process shows lower concentrations. It is also possible that primary calcite is enriched in trace elements if an Amorphous CaCO3 (ACC) or vaterite precursors are involved. In addition, Rayleigh fractionation from a semi-closed reservoir, the presence of high Mg in the lattice or any combination of the previous causes may explain the trace elements enrichment. Changes in the DIC did not affect the pattern of elemental cycles in these foraminifera, suggesting that this variability is inherent to the biomineralization process.

Novel nano-sized biphasic calcium phosphate bioceramics (β-CPP/β-TCP) derived of lime mud waste

In this work, novel BCP (β-CPP, β-Ca2P2O7/β-TCP, β-Ca3(PO4)2) bioceramics have been synthesized by wet chemical precipitation using lime mud waste from cellulose industry as inexpensive sustainable CaCO3 precursor source. The synthesized BCP bioceramics have been characterized regarding to X-ray diffraction (XRD), Rietveld refinement, scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The results indicated that the amounts of the phases β-CPP and β-TCP in the biphasic mixtures depend on the different HNO3 molar concentrations used in the synthesis. In addition, the BCP (β-CPP/β-TCP) powders exhibited average crystallite size in the range of 55.56 to 59.85 nm. Such novel BCP nanopowders produced by using CaCO3 from lime mud waste have high potential for biomedical applications.

NaBr-Enhanced CaO-Based Sorbents with a Macropore-Stabilized Microstructure for CO2 Capture

Calcium looping process (CaLP) is well-considered as a cost-effective scenario for trapping CO2 from flue gas. However, the CO2 capture capacity of natural CaO-based sorbents spoils rapidly over long-term cycles. In this work, NaBr was introduced to enhance the cyclic CO2 capture capacity of CaO sorbents. The NaBr-modified CaO showed an improved activity and durability for carbonation. After 100 cycles, the “NaBr/CaO-10/100” maintained a capacity of 0.202 g CO2/g sorbent, which was about 185% higher than that of unmodified CaCO3 precursor. The mechanism of enhancement was analyzed by a simultaneous thermal analyzer (STA), in situ X-ray powder diffraction (in situ XRD) instrumentation, an inductively coupled plasma optical emission spectrometer (ICP-OES), a field emission scanning electron microscope coupled energy dispersive X-ray spectrometer (FSEM-EDS), and N2 physical absorption analysis, and the results showed that the modified sorbent formed a well-linked macropore structure, which was relatively sta...

Calcium precursor from stirring processes at room temperature for controllable preparation of nano-structure CaO sorbents for high-temperature CO2 adsorption

Nano-structure CaO crystals with an average size of 480 nm × 255 nm (length and width) were prepared by simply roasting CaCO3 precursors at 900 °C for 2 h. The CaCO3 precursors with a pure vaterite crystalline phase were readily synthesized by a room temperature stirring method using Ca(NO3)2 and CO2 storage material (CO2SM). The CO2SM played an important role in providing CO32− source and structure controlling. The effects of CO2SM dosage, Ca2+ concentration, and stirring time on the crystallization of CaCO3 precursors were investigated. In addition, the CO2SM was successfully regenerated by simply exposing the filtrate from the preparation process to CO2 for further preparing CaCO3 precursor. The as-obtained CaO crystals exhibited a strong CO2 adsorption capacity up to 17.18 mmol g-1 under 0.1 MPa at 700 °C.

Photocatalyst of Perovskite CaTiO3 Nanopowder Synthesized from CaO derived from Snail Shell in Comparison with The Use of CaO and CaCO3

Calcium titanate belongs to the important group of compounds with a perovskite structure having high dielectric loss for various applications including photocatalysis mechanism. Refer to the principles of green chemistry, in this work preparation of CaTiO3 was conducted by using CaO derived from snail shell. Aim of this research are to study the physicochemical character of perovskite derived from snail shell and its comparison with CaO and CaCO3 as Ca sources. Material preparation was performed by solid reaction of Ca sources with TiO2 under comparison with CaO and CaCO3 precursors. Mixture of Ca sources with TiO2 in certain proportion were ground and calcined at the temperature of 200 °C for 2 hs. Materials were characterized by using X-ray diffractometer (XRD), Fourier Transform-Infra Red (FTIR) and the photocatalytic activity was tested by using methylene blue photooxidation. Perovskite synthesized using CaO derived from snail shell exhibits the similar XRD pattern with that were prepared by using CaO and CaCO3. From the photooxidation activity test, it is proven that CaTiO3 shows similar photocatalytic activity correspond to that were prepared by CaO and CaCO3. Utilazation of shell as agricultural waste of the synthesis of CaTiO3 perovskite is the novelty of this work. Furthermore, the study on material structure and photoactivity is the main focuses for the application in industry and environment.

Investigation on electrical properties of BCZT ferroelectric ceramics prepared at various sintering conditions

ABSTRACTThe influence of sintering conditions on phase formation, density, microstructure and electrical properties of BCZT ceramics wer investigated. The BCZT (Ba0.85Ca0.075Zr0.1Ti0.9O3) ceramics were fabricated by a mixed oxide synthetic route of BaCO3, CaCO3, ZrO2 and TiO2 precursors and then sintered at 1250, 1300 and 1350°C for 2 and 4 hrs. Phase formation, densification, microstructure surfaces, dielectric properties, ferroelectric and piezoelectric properties were analyzed by using X-ray diffraction (XRD), Archimedes method, Scanning Electron Microscopy (SEM), LCR Meter, P-E hysteresis and d33 meter, respectively. In processes of sintering, the results show that BCZT structures are perovskite with pseudo-cubic phase. Sintering condition at 1300°C for 4 hrs exhibits optimum density, grain size and higher electrical properties: density 5.62 g/cm3 (∼98% of theoretical density), average grain size = 2.19 ± 0.87 µm, dielectric constant (ϵr) = 2840, dielectric loss (tan δ) = 0.10, remanent polarization (Pr) = 5.84 µC/cm2 and d33 = 167 pC/N.

Physical properties of CaCuO2 target into the thin film deposition

The CaCuO2 target was prepared by solid state reaction (SSR) method from CaCO3 and CuO precursor powders. These precursor powders were mixed with mortar, and pressed by single hydraulic for sintering at temperature 600, 650, 700, and 750 ˚C within the thermogravimetric-differential thermal analyses (TG-DTA). The phase identification, atomic composition, hardness, and density of CaCuO2 target were measured and analyzed by X-ray diffraction (XRD) and energy dispersive X-ray (EDX), micro hardness tester and density kit techniques, respectively. It was found that, the CaCuO2 target shows nearly single phase, responded chemical composition, and high density after sintered at 700 ˚C. This result shows best target for deposition thin film by DC magnetron sputtering.