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In this work, stacked SiC fibers paper‐reinforced SiC ceramic matrix composites (SiCnf/SiC CMCs) were prepared by nanoimpregnation and transient eutectic (NITE) process using ultra‐long single‐crystal SiC nanofibers. The effect of the SiCnf surface modification via boron nitride (BN) interphase deposition as well as the sintering additive (Al2O3–Y2O3) content on the density, microstructure, and mechanical properties of SiCnf/SiC CMCs has been investigated systematically. The results revealed that the laminated SiCnf/SiC CMCs feature a significant saw‐tooth‐like curve on the load–displacement test, which indicates that the obtained laminated structure with the weak interlayer binding owning to the BN coating treatment possesses significant toughening to the SiC ceramics. Specifically, the SiCnf/SiC CMCs with the sintering additive content of 12 wt% revealed a fracture toughness of over 10 MPa m1/2 after 60 min of BN interface deposition, which is 104.31% higher than that of the composites prepared without BN coating. [ABSTRACT FROM AUTHOR]

Accelerated thermal aging was conducted on Kraft papers impregnated with mineral insulating oil (MO) and palm insulating oil (PO), and the effect of aging time on the oils and Kraft papers was observed. Each sample consisted of insulating oil, dried Kraft paper, and weighed metal catalysts (copper, iron, zinc, and aluminum) in a bottle. Prior to aging, the bottles were left for 24 h at room temperature for impregnation to take place. The thermal aging experiments were carried out at 130 °C for 250, 500, and 750 h. The properties of the MO and PO (moisture content, acidity, and ultraviolet-visible absorption spectra) and the properties of the Kraft papers (tensile strength and colour) were determined. Results showed that the aged PO had higher moisture content compared with the aged MO. However, the Kraft papers impregnated with PO had better tensile strength after 750 h of aging, which may be attributed to the affinity of PO to moisture. This slows down the hydrolytic degradation mechanism. In terms of colour, the Kraft papers were darker than their original colour as the tensile strength decreased. To conclude, the Kraft paper impregnated with PO had higher tensile strength compared with those impregnated with MO. [ABSTRACT FROM AUTHOR]

Ag@ceramic composite papermaking pigment was prepared by coating silver onto red ceramic powder using the electroless plating method. SEM and XRD showed that the ceramic pigments have a porous crystalline structure and that silver particles had been successfully loaded onto the surface and into the pores of the Ag@ceramic. Untreated ceramic pigment and Ag@ceramic pigment were incorporated into paper sheets by coating, filling and filling‐coating. Using spinach as an example, the ability of the different papers to preserve food was then evaluated. Four indicators were used to assess the preservative effect of the papers: inhibition of growth of Staphylococcus aureus and Escherichia coli, weight loss of the spinach and retention of vitamin C and chlorophyll in the spinach. Although the ceramic preservative paper has no antibacterial properties, it reduced weight loss from the spinach and increased retention of vitamin C and chlorophyll. The antibacterial preservative papers inhibited the growth of E. coli and S. aureus by >99%, and because of their additional antibacterial activity, these papers preserved the spinach more effectively. The experimental results showed that the antibacterial food‐preservative paper incorporating ceramic pigments had great potential in food packing applications. [ABSTRACT FROM AUTHOR]

Background: Re‐use of wastes as a part of sustainable development is one of the most important aspects of a healthy human life and environmental protection. This study examines the viability of using paper industry slag for the production of building ceramics. Results: Paper industry slag was used in the production of ceramic bricks as a burnable additive in amounts of 5, 10 and 15 wt%. The slag was introduced without and after three different preparatory operations: dried, dried and ground, granulated and dried. Clay was used as a raw material and quartz sand as a lean additive. The samples were made by plastic molding. Drying was carried out at a temperature of 100 °C. To determine the optimal heat treatment temperature, firing was carried out at 900, 950, 1000 and 1050 °C with holding at the maximum temperature for 30 min, followed by determination of the properties of the samples. Conclusions: It has been established that the samples obtained using the slag have good physical and mechanical properties and comply with current standards. At the same time, the use of slag in the production of ceramic bricks makes it possible to solve the problem of waste management, as well as to obtain a secondary material resource from the slag – a burnable additive, which leads to savings in raw materials and energy resources in the production of ceramic bricks. © 2022 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

[001]-textured 0.4P(Mg1/3Nb2/3)O3-0.25PbZrO3-0.35PbTiO3-0.5%MnO2 (Mn-PMN-PZT) ceramics were fabricated by templated grain growth using 2 vol. % BaTiO3 in this paper. Full matrices of dielectric (ɛij), elastic (sij, cij), and piezoelectric (dij) parameters were obtained by the resonance–antiresonance method. The dielectric constant ɛ33T of textured ceramics reaches 2600, which is four times that of random ceramics. Textured Mn-PMN-PZT ceramics exhibit high d33 = 984 pC/N and high k33 = 0.89, which is much larger than d33 = 223 pC/N and k33 = 0.70 of random ceramics. However, ɛ11T of ceramics decreases by about 30% after texturing, and the corresponding shear coupling coefficient k15 also decreases from 0.66 to 0.44, which may be due to the reduction in the angle between spontaneous polarization and transverse direction. Furthermore, the temperature stability of the textured ceramics was evaluated as well. The phase transition temperature TR−T was determined by the impedance method to be 120 °C. The textured Mn-PMN-PZT ceramic shows high temperature stability, which is better than PMN-PT. [ABSTRACT FROM AUTHOR]

With the increasing demand for the resilient capacity of transformers in high-proportion renewable energy grids, the overload capacity of transformers and the thermal conductivity of winding insulation materials have been put forward as important requirements. In response to these requirements, a novel ceramic high temperature tolerance insulation winding is proposed in this paper and is applied in a ceramic insulated winding transformer. A combination of simulation and experimentation is used to analyze the thermal-flow characteristics of this transformer. The temperature and flow field distribution characteristics of transformers with both winding insulation methods (ceramic and Nomex paper) are compared. The internal mechanism of reflux near the iron core and high voltage winding under forced air cooling is clarified. A superior outside cooling condition is obtained. A prototype ceramic insulated winding transformer is developed and tested to verify the accuracy of the simulation model. The results show that the hotspot temperature of the ceramic insulated winding transformer under natural cooling is 10.7% lower than that of the Nomex paper insulated winding transformer. With forced air cooling of 2, 3, 4, 5, and 6 m/s applied at the bottom, the hotspot temperature of the ceramic insulated winding transformer is 11.4%, 10.5%, 9.7%, 14.0%, and 17.8% lower than that of the Nomex paper insulation winding transformer, respectively. Under forced air cooling, a reflux phenomenon is observed in both transformers in the vicinity of the iron core and high voltage winding due to the formation of adverse pressure gradient region and wall viscous force blocking. The strength of the reflux is affected by the magnitude of the forced air cooling flow velocity and the construction of the transformer. The optimal range of the external cooling flow velocity for the ceramic insulated winding transformer is 3–4 m/s. The errors between the simulated temperature and the measured temperature at the nine monitoring points of the prototype are all less than 5%, which verifies the effectiveness of the simulation model. The experimental and theoretical basis for the design and application of resilient capacity dry type transformers is provided by this research. [ABSTRACT FROM AUTHOR]

Fibers represent a type of structure of great interest in catalysis since they combine high area to volume ratio and can be fabricated from many types of materials, such as ceramic oxides, polymers, and alloys. They can be used in isolated form or structured, as in the case of the ceramic papers synthesized in this work, following a modified papermaking technique. The addition of cationic and anionic polyelectrolytes improved the retention of ceramic fibers during the ceramic paper formation stage by adsorption processes, through the formation of floccules. In the complex aqueous system containing charged macromolecules, the amounts of polyelectrolytes to be added were determined by titrations. To enhance mechanical properties of ceramic papers, different classes of nanoparticle suspensions can be used as binders. As a novel alternative, we have used different borate-type compounds. Among them, we selected natural ulexite, which was purified and used as a binder of ceramic fibers. In order to improve mechanical resistance and flexibility, measured from tensile indexes and elastic module, the amounts of NaCaB5O6(OH)6.5H2O and the calcination temperature were varied. In this contribution, to take advantage of the unique characteristics of the ulexite-containing ceramic papers, they were impregnated with Co,Ce and Co,Ba,K and tested for diesel soot combustion. [ABSTRACT FROM AUTHOR]

Due to their exceptional impact resistance, ceramics are extensively used in various fields. However, unavoidable pores, microcracks, and inherent defects can degrade the performance of ceramic materials. A damage model of SiC ceramics under passive confining pressure was constructed based on the Lemaitre strain equivalence principle and the Weibull distribution function. This paper presented a dynamic damage model for SiC ceramics subjected to passive confinement pressure based on the principles of damage mechanics. Additionally, the split Hopkinson pressure bar device was employed to investigate the compressive strength and damage evolution of SiC ceramics at various shock pressures and confinement degrees. The experimental results indicate that constraints can reduce the damage to ceramics. The metal sleeve increased stiffness when compressing the ceramic material, allowing the specimen to convert from brittle–plastic–brittle. When sufficient constraints can be provided, the peak strain decreases gradually with the increase of the impact air pressure. Experimental data showing good agreement with the proposed model validated and analyzed the established model. Thinner boundary constraints cannot maintain the stability of ceramic structures, thicker boundaries do not significantly improve performance, and thicker boundaries can cause more weak areas. This paper provides guidance for the design of encapsulated ceramic composite armor by quantitatively studying the constraint thickness. [ABSTRACT FROM AUTHOR]

Introduction: In this paper, recent developments in non-destructive testing of 3D-printed ceramics and monitoring of additive manufacturing of ceramics are presented. Methods: In particular, we present the design and use of an inline midinfrared optical coherence tomography (MIR-OCT) system to evaluate printed and micro-structured specimens in lithography-based ceramic manufacturing (LCM). Results: The proposed system helps with the detection of microdefects (e.g., voids, inclusions, deformations) that are already present in green ceramic components, thereby reducing the energy and costs incurred. Discussion: The challenges during integration are discussed. Especially, the prospects for MIR-OCT imaging combined with machine learning are illustrated with regard to inline inspection during LCM of printed ceramics. [ABSTRACT FROM AUTHOR]

A comprehensive review of the application of different ceramics for MEMS devices is presented. Main ceramics materials used for MEMS systems and devices including alumina, zirconia, aluminum Nitride, Silicon Nitride, and LTCC are introduced. Conventional and new methods of fabricating each material are explained based on the literature, along with the advantages of the new approaches, mainly additive manufacturing, i.e., 3D-printing technologies. Various manufacturing processes with relevant sub-techniques are detailed and the ones that are more suitable to have an application for MEMS devices are highlighted with their properties. In the main body of this paper, each material with its application for MEMS is categorized and explained. The majority of works are within three main classifications, including the following: (i) using ceramics as a substrate for MEMS devices to be mounted or fabricated on top of it; (ii) ceramics are a part of the materials used for an MEMS device or a monolithic fabrication of MEMS and ceramics; and finally, (iii) using ceramics as packaging solution for MEMS devices. We elaborate on how ceramics may be superior substitutes over other materials when delicate MEMS-based systems need to be assembled or packaged by a simpler fabrication process as well as their advantages when they need to operate in harsh environments. [ABSTRACT FROM AUTHOR]

The ultra-high-frequency pulse trains in a Yb:LuAG passively Q-switched laser with a Yb ratio of 15 at. % are experimentally investigated. The pulse trains consist of a low-frequency harmonic spectrum pulse train with a fundamental frequency below 500 KHz as the source and an ultra-high-frequency harmonic spectrum pulse train with an exciting fundamental frequency above 104 KHz. The basic frequency of the low spectrum increases approximately linearly with increasing pump power. The change law of the fundamental frequency of the ultra-high frequency spectrum with the increase in pump power conforms to the frequency-doubling principle of the harmonic spectrum changing to a higher frequency, and increases exponentially with A × 2n (n is a natural number, A = 1.25 × 108, 1.552 × 108, or 1.0 × 108 Hz). In this paper, the base frequency range of the ultra-high-frequency spectrum was 0.077 73 GHz–0.66 THz. The maximum average peak power of an ultra-high-frequency pulse was 18.25 mW, and the minimum width of an ultra-high-frequency pulse was 3.2 ps. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rapid technological advancements in recent years have opened the door to innovative solutions in the field of telecommunications and wireless systems; thus, new materials and manufacturing methods have been explored to satisfy this demand. This paper aims to explore the application of low-cost, commercially available 3D-printed ceramic/polymer composite filaments to design dielectric resonators (DRs) and check their suitability for use in high-frequency applications. Three-dimensional printing was used to fabricate the three-dimensional dielectric resonant prototypes. The filaments were characterized in terms of their thermal and mechanical properties and quality of printability. Additionally, the filaments' dielectric properties were analyzed, and the prototypes were designed and simulated for a target frequency of ~2.45 GHz. Afterward, the DRs were successfully manufactured using the 3D printing technique, and no post-processing techniques were used in this study. A simple and efficient feeding method was used to finalize the devices, while the printed DRs' reflection coefficient (S11) was measured. Results on prototype size, manufacture ease, printability, cost per volume, and bandwidth (BW) were used to evaluate the materials' suitability for high-frequency applications. This research presents an easy and low-cost manufacturing process for DRs, opening a wide range of new applications and revolutionizing the manufacturing of 3D-printed high-frequency devices. [ABSTRACT FROM AUTHOR]

This paper reports the dielectric characterizations of (Ca0.95Sr0.05)(Ti1−xSnx)O3 ceramics prepared using a solid-state reaction method with various x values. X-ray diffraction spectroscopy analyses showed that the crystal structure of these pure samples was orthorhombic perovskite. With increasing Sn4+ content, the lattice constant and unit cell volume increased, while the dielectric constant decreased because of the ionic polarizability decreasing. Moreover, a maximum Q × f value of 5242 (GHz), a dielectric constant (εr) of 91.23, and a temperature coefficient (τf) of +810 ppm/°C were achieved for samples sintered at 1350 °C for 4 h. The microwave dielectric characterization was found to be strongly correlated with the sintering temperature, and the best performance was achieved for the sample sintered at 1350 °C. (Ca0.95Sr0.05)(Ti1−xSnx)O3 possesses a promising potential to be a τf compensator for a near-zero τf dielectric ceramic applied in wireless communication systems. [ABSTRACT FROM AUTHOR]

The formation of defects, due to drying, in robocasted ceramic objects is an important issue arising from non-uniform shrinkage of the material during this step in the process. Common methods for shrinkage measurement are not well suited to the small size of robocasted cords or the complexity of robocasted objects. Innovative methods for shrinkage measurement were developed using non-destructive optical vision techniques with computer-controlled data acquisition, allowing measurement on millimetric cords and on specific zones of a product. The study of a single porcelain cord revealed an anisometric shrinkage related to the orientation of grains during extrusion. A differential shrinkage at the macroscopic scale was also measured on a robocasted object, indicating a moisture content gradient in the material. The methods presented in this paper are of particular relevance to real-time control of the drying process for robocasted objects. [ABSTRACT FROM AUTHOR]

The Kingdom of Navarre was a Christian kingdom located in the north of the Iberian Peninsula during the Middle Ages. Its location on the west of the isthmus between the Iberian Peninsula and the European continent allowed an exchange of cultural currents. The main pottery production centres were in Estella, Lumbier, Pamplona, Tafalla, and Tudela. Ceramic pastes from various mediaeval sites were analysed for both elemental and mineralogical composition determination. The results were evaluated using Principal Component Analysis and allowed us to identify each production centre. Each manufacturing centre showed a different and characteristic composition of raw materials. Ceramics from Tudela were Ca-, Mg-, Na-, and Sr-rich. Ceramics from Estella were richer in Al, K, and Ti. Ca, Sc, and Sr contents were higher in Tafalla ceramics. Lumbier ceramics stood out for being enriched in Si, Mn, Fe, and Zr. Pamplona ceramics showed intermediate values. The analysis of samples from other Navarrese locations allowed us to begin to define what the commercial ceramic network in the Kingdom of Navarre was like during the Middle Ages. Therefore, two aims were defined for this paper: to characterise the ceramic pastes for each of the producing centres and to know where the ceramics were exported to. [ABSTRACT FROM AUTHOR]

Well known for vibrant ideological energy, Nsukka School is home to several renowned artists whose impacts are felt globally. Among them are artists of various specialties including painting, sculpture, graphics, and ceramics. This paper presents a review of the ceramic works of key ceramicists from Nsukka School--Echeta, Ozioma Onuzulike, and Ngozi Omeje. While these ceramicists have, in recent times, continued to soar on the international art scene, the background of their practices, particularly as artists from the Nsukka art school, needs to be reviewed. With a specific focus on the artists' ceramic installations, the works of these artists between 2000 and 2010 are, therefore, presented and analyzed. While the study is anchored in the background of Nsukka School and the persistent ideologies for which the school is known, the uniqueness of the artists' works is also foregrounded. The study relied on extant literature, in-depth interviews with each of the artists, and a personal observation of their works. The data analysis involved the narrative and comparative methods. By presenting a background to the current practices of the Nsukka ceramicists, this study provides a backdrop upon which their work and those of many more artists could be studied and understood. [ABSTRACT FROM AUTHOR]

Copyright of Praehistorische Zeitschrift is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two commercial stoneware pastes traditionally used to produce ceramic objects were evaluated. The objective was the comparative characterization of the pastes and to find the most suitable to obtain fine ceramic objects using the pottery wheel. Both ceramic pastes were characterized by X-ray powder diffraction (XRPD), particle size analyses (laser diffraction) and thermal analyses (thermogravimetry-TG, its derivative-DTG, and differential thermal analysis-DTA). The technological properties like linear drying and firing shrinkage, moisture content and plasticity were also determined. The results showed that both pastes have appropriate properties making them suitable for plastic shaping by pottery wheel. In addition, the stoneware paper clay paste is "greener" due to its content of cellulose fibers which can come even from recycled paper. [ABSTRACT FROM AUTHOR]

Polymer matrix solid buoyancy materials (PSBMs) have the advantages of low density, high strength, low cost, and low water absorption, and they are widely used in marine engineering fields. How to improve the performance of PSBMs further and adapt them to harsh marine environments has become a hot topic in current research. This paper provides a comprehensive summary of PSBM, detailing both the preparation methodologies and properties of single-component and multi-component PSBM. In this paper, relevant research is systematically summarized from two dimensions of matrix and filler, and the application of thermosetting resin and thermoplastic resin as a matrix in PSBM is introduced in detail, and the corresponding research on fillers such as hollow glass microspheres, fly ash, hollow ceramic spheres and hollow polymer microspheres are expounded. This paper aims to summarize the latest advancements in PSBM research, thereby providing insights into the current state of the field and guiding future investigations. [ABSTRACT FROM AUTHOR]

Three-dimensional digital technology has made breakthroughs and shown unique advantages in all walks of life. On the basis of practicality, the three-dimensional artistic design of ceramic products gradually adds some aesthetic, artistic design elements, which brings beautiful enjoyment to people's lives and makes people's lives colorful. This paper presents a three-dimensional artistic design method for ceramic products based on RNN (recurrent neural network) technology. With the establishment of the 3D YOLOv3 framework, the new model training is faster and more stable, the convergence speed of the loss function is faster, and the reconstructed 3D model is more accurate. After training for a certain number of times, the network gradually becomes stable, the accuracy rate is kept at 95%, and the loss function value is reduced below 0.2. The accuracy of the network model and the precision of semantic segmentation are improved. The semantic segmentation and object recognition under 3D scene reconstruction studied in this paper have certain theoretical value and high feasibility. [ABSTRACT FROM AUTHOR]

The book "Western Ceramic Traditions: Prehistoric and Historic Native American Ceramics of the Western U.S." edited by Suzanne Griset explores the diversity of ceramic traditions and social identities reflected in pottery production in the far southwestern desert and coastal region of the U.S. The book features 11 chapters that critically examine traditional typologies of plainware pottery and explore new datasets for dating and identifying the composition of pottery. The volume provides important discussions on the sociocultural aspects of pottery technology and challenges the limitations of typological classification. The book is recommended for researchers working with plainware or other ceramic wares, although the technical ceramic data presented may be daunting for readers without an archaeological or ceramic analyst background. [Extracted from the article]

In spite of the flexoelectric effect being a universal phenomenon in the ferroelectric perovskites, the current understanding of flexoelectric aging in ferroelectrics is, actually, rather incomplete. In this paper, we have fabricated a series of Mn-doped BaTiO3 perovskite ceramics (BaTi1–xMnxO3, x = 0.1% and 1%, BTMO) to systematically investigate the corresponding flexoelectric aging behavior by controlling the concentration of Mn. We found that the variation of Mn dopant significantly effects the Curie temperature, dielectric constant, flexoelectric aging, and flexoelectric coefficient of the BTMO ceramics. Especially for the BTMO (0.1%) ceramics, obvious ferroelectric aging and flexoelectric aging phenomenon are observed at room temperature. The main reason for aging of BTMO ceramics is that the doping of Mn introduces oxygen vacancies, which tend to be stable under the action of strain gradient and electric field. Therefore, the results presented in this paper verify that the flexoelectric aging in Mn-doped BTO ceramics is closely related to ferroelectric fatigue. [ABSTRACT FROM AUTHOR]

Cellulose‐based paper samples were surface‐modified by a polymeric single‐source precursor prepared from perhydropolysilazane (PHPS) and iron(III)acetylacetonate (Fe(acac)3) and ammonolyzed at 500°C, 700°C, 900°C, and 1000°C, leading to C/SiFe(N,C)O‐based ceramic papers with in situ‐generated hierarchical micro/nano‐morphology. As reference, cellulose‐free samples were prepared under the same conditions. Upon thermal treatment, the microstructure evolutions of the resulting ceramic paper and the reference sample were comparatively investigated. Scanning electron microscopy (SEM) showed that for all temperatures, the ceramic papers exhibit the same morphology as the template, however, with noticeable shrinkage and curling, particularly evident at higher temperatures. X‐ray diffraction (XRD) measurements of the reference samples and the ceramic papers showed a similar crystallization behavior and phase evolution in both materials. In the ceramic paper, the crystallization process seems to occur at a later time. The results provide a comprehensive understanding of the investigated C/SiFe(N,C)O‐based ceramic system. It was shown that use of the cellulose‐based paper template has the benefit of retaining the microstructure and furthermore, apart from transforming the cellulose fibers into turbostratic carbon, does not change the phase evolution during the polymer‐to‐ceramic transformation, allowing at the same time the manufacturing of novel morphologically complex parts by a convenient one‐pot synthesis approach. [ABSTRACT FROM AUTHOR]

SiFeO(N,C)‐based ceramic papers were prepared via a one‐pot synthesis approach by dip‐coating a cellulose‐based paper template with a polymeric perhydropolysilazane precursor modified with iron(III)acetylacetonate. The preceramic composites were subsequently pyrolyzed in ammonia atmosphere at 500, 700, and 1000°C, respectively, and the characteristics of the three resulting ceramic papers were comparatively investigated. Scanning electron microscopy revealed that in each sample, the morphology of the template is successfully transferred on the ceramic system, with the cellulose‐derived fibers being converted to elemental carbon encased by a SiFeO(N,C) coating. Electron transparent cross‐sectional samples for transmission electron microscopy (TEM) were prepared from the ceramic papers, employing a standard ultramicrotomy slice cutting procedure, allowing for a detailed characterization of their in situ generated micro‐/nanostructure as well as occurring crystalline phases. TEM imaging and diffraction revealed that depending on pyrolysis temperature a different microstructure with a distinct phase assemblage is generated in the polymer‐derived ceramic papers. Crystallization from the polymer precursor starts with the precipitation of wüstite (Fe(1‐x)O) nanoparticles at 700°C inside the ceramic coating and secondary ε‐FexN at the fiber‐coating interface. Upon pyrolysis at 1000°C however, the sample primarily accommodates metallic α‐iron nanocrystals that impart ferromagnetic characteristics to the ceramic paper. The results show that the template‐assisted polymer‐derived ceramic route is a feasible approach in the production of complex ceramic compounds with fibrous paper‐like morphology. By adjusting the pyrolysis temperature, microstructure and phase composition of the ceramic paper can be conveniently tailored to the needs of its respective application. [ABSTRACT FROM AUTHOR]

In this paper, the crystallization behavior of 50ZnO:47B2O3:3Nb2O3:0.5Eu2O3 (G-0 h) glass has been investigated in detail by DSC, XRD and TEM analysis. The luminescent properties of the resulting glass-ceramics were also investigated. By XRD and TEM analysis, crystallization of several crystalline phases has been proved (α-Zn3B2O6, β-Zn3B2O6 and ZnNb2O6). By calculating crystal parameters, it was found that europium ions are successfully incorporated in the β-Zn3B2O6. Photo-luminescent spectra showed increased emission in the resulting glass-ceramic samples compared to the parent glass sample due to higher asymmetry of Eu3+ ions in the obtained crystalline phases. It was established that the optimum emission intensity is registered for glass-ceramic samples obtained after 25 h heat treatment of the parent glass. [ABSTRACT FROM AUTHOR]

This paper presents a study of ceramics from Northwest China from the Neolithic and Bronze Age (c. 3300–600 BCE), providing insights into variations in human–ceramic interactions over time and space. Based on macroscopic and petrographic analysis of ceramics from 10 sites, this paper shows that there is much more complexity in ceramic technology than previously thought. It identifies a development from a bi‐modal distinction between painted fine ware and rusticated coarse wares shared among communities across Northwest China to strongly localised ceramic traditions with new fabrics, vessel shapes, and decorations, some of them potentially of outside origin, reflecting considerable societal change. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive analysis of the utilization of 3D printing technology for the fabrication of ceramic shells in the context of investment casting. This study encompasses an exploration of various 3D printing techniques such as binder jetting technology and lithography-based ceramic manufacturing applied to ceramic materials tailored for investment casting applications for different materials. Comparative analyses between conventionally manufactured shells and those produced through 3D printing techniques are presented, shedding light on the potential advantages and challenges associated with the adoption of additive manufacturing in investment casting processes. The findings of this study reveal that both methods offer viable solutions for creating ceramic materials suitable as shells for investment casting. Both lithography-based ceramic manufacturing and binder jetting technology exhibit unique advantages and challenges. Lithography-based ceramic manufacturing demonstrates a superior surface finish and resolution, making it particularly suitable for intricate designs and fine details. On the other hand, binder jetting technology presents advantages in terms of speed and scalability, allowing for the rapid production of larger components. [ABSTRACT FROM AUTHOR]

The conventional manufacturing chain for technical ceramics is too expensive for the production of small series or unique parts with complex designs. Hybrid machines that combine additive and subtractive processes can be an interesting solution to overcome this technology lock-in. However, despite the great interest in hybrid machines for metallic parts, there is a lack of data in the literature when it comes to ceramics. The purpose of this paper is to contribute to closing this gap. It is the first to evaluate the achievable geometrical tolerances according to ISO 2768-2 as well as the surface textures of composite zirconia parts shaped sequentially by pellet additive manufacturing (PAM, from ceramic injection molding feedstock) and finish milling. The green parts were then debinded and sintered to analyze the influence of these steps. Compared to the initial green parts, the sintered parts exhibited shiny and smooth surfaces with sharp edges. Flatness, parallelism and perpendicularity all achieved an H (fine) class, while the surface textures were significantly improved, resulting in arithmetic roughness (Ra) below 1.6 µm. [ABSTRACT FROM AUTHOR]

In this paper, based on our previous expertise on ceramic artifacts, several archaeometric methods applied to some samples collected from the Dudești archaeological site (Oltenia region, Romania) are reported for the first time in the literature. The chemical composition, and microstructural and morphological characterization of these samples offer important conclusions about the processing conditions. Some specific techniques such as X-ray diffraction (XRD), wavelength-dispersive X-ray fluorescence (WDXRF), optical microscopy (OM), stereomicroscopy, environmental scanning electron microscopy (ESEM), Fourier-transform infrared spectroscopy (FTIR), and Raman spectroscopy provide compositional information about composition and the decay processes. Additionally, the Brunauer–Emmett–Teller (BET) method helps to estimate pore sizes and specific surface areas. A thermogravimetric analysis (TGA/TDG) was used to establish details regarding the production technology and also the raw materials source used to make the ceramics. The obtained results indicated that the ceramics are based on a paste of muscovite and feldspar, with high plasticity, together with quartz and hematite/goethite and calcite, the latter in very low concentrations. According to the obtained results, we could assume that clays from the investigated samples had a low concentration of calcium. Gypsum is present as paste in a very low concentration, identified by the presence of a sulphate group in WDXRF. In the same context, iron oxides have a significant impact on the firing atmosphere of iron-rich clay, resulting in blackening under reducing conditions and a reddish coloration under oxidative conditions. The use of hematite and gypsum as pigments further contributes to the color variations in the pottery. The consistent firing temperature range of 200–600 °C in Dudești pottery implies a standardized production process, the variation in color being dependent on the specific reducing/oxidative regime conditions (reducing atmosphere followed by rapid oxidation). This relationship between clay composition and local sources suggests a connection to Neolithic pottery production in the region and their color depending on the reducing/oxidative regime conditions. [ABSTRACT FROM AUTHOR]

The outstanding thermal, chemical, and mechanical properties of ceramic membranes have attracted increasing attention, offering advantages over polymer and metal counterparts. Exploring the specialized applications of ceramic membranes through various preparation methods poses a daunting challenge for contemporary researchers. Traditional preparation methods are essentially unable to meet the requirements of complex membrane structures. For instance, in ceramic fuel cell applications, cells composed of ceramic membrane materials exhibit high resistance and low conductivity, which seriously hinders the progress of new high-performance ceramic fuel cells. Therefore, it is necessary to improve preparation methods to improve the electrochemical performance of devices composed of ceramic membrane materials. In recent years, breakthroughs in various new processing technologies have propelled the performance of ceramic membrane devices. This paper will focus on the following aspects. Firstly, traditional preparation methods and advanced preparation methods of ceramic membrane materials will be discussed. Secondly, high-performance ceramic membrane materials prepared by different advanced preparation methods are introduced, and the electrochemical properties of the devices composed of ceramic membrane materials are elaborated in combination with different testing and characterization methods. Finally, the prospects and future direction of the preparation of ceramic membrane materials by advanced preparation methods are summarized. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to understand the vibration characteristics of full ceramic ball bearings under grease lubrication, reduce the vibration of the bearings and improve their service life. Design/methodology/approach: The Hertz contact stiffness formula for full ceramic ball bearings is constructed; the equivalent comprehensive stiffness calculation model and vibration model of full ceramic ball bearings are established. The dynamic characteristic test of full ceramic ball bearing under grease lubrication was carried out by using the bearing life testing machine, and its vibration was measured, and its vibration acceleration root-mean-square was obtained by software calculation and compared with the simulation results. Findings: At the rotational speed of 12,000 r/min, the root-mean-square value of vibration acceleration is maximum 10.82 m/s2, and the error is also maximum 7.49%. As the rotational speed increases, the oil film stiffness decreases. In the radial load of 600 N, the vibration acceleration root-mean-square is minimum 6.40 m/s2, but its error is maximum 6.56%. As the radial load increases, the vibration of the bearing decreases and then increases, so under certain conditions increasing the radial load can reduce the bearing vibration. With different types of grease, the best preload is also different; low-speed heavy load should be used when the viscosity of the grease is large, and high-speed light load should be used when the choice of smaller viscosity grease is made. Originality/value: It provides a theoretical basis for the application of full ceramic ball bearings under grease lubrication, which is of great significance for reducing the vibration of bearings as well as enhancing the service life of bearings. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2024-0094/ [ABSTRACT FROM AUTHOR]

The 1D moisture diffusivity of porous materials may strongly depend on the content of moisture in the materials, varying over an order of magnitude or more. In this paper we present a new model from which the diffusivity can be evaluated, using the pore size distribution and water absorption coefficient. We point out that this is a more efficient approach than the standard Boltzmann–Matano (BM) method, because measurements of pore curves and water absorption are much shorter and rather accurate compared to moisture profile experiments needed in the BM method. As an example, we apply our model to two samples of a ceramic brick for which experimental data on both pore curves and moisture profiles had been measured. A very good quantitative agreement in the diffusivity is obtained for early stage profiles. For later stages, however, the model predicts three to four times higher diffusivity than the BM method. The reasons for this discrepancy are discussed and further tasks to validate the effectiveness of the new model are proposed. We also compare our model with the pore models of Burdine and Mualem. [ABSTRACT FROM AUTHOR]

The use of SiO2 ceramic materials is increasingly prevalent in both industrial and artisanal craftsmanship. These materials exhibit excellent mechanical properties, making them challenging to process, especially after firing. The paper explores the application of CO2 lasers for engraving ceramic materials, addressing challenges in traditional processing methods and offering insights into optimizing laser parameters for enhanced engraving performance. Through simulations using COMSOL Multiphysics software and experimental validations, the thermal interaction between CO2 lasers and SiO2 ceramic substrates is thoroughly investigated. Parameters such as power, scanning speed, pulse width, and repetition frequency are examined to understand their influence on engraving depth, resolution, and surface quality. The research compares continuous wave (CW) and pulsed modes, highlighting their advantages and limitations. The most suitable set of technological parameters is selected for experimentations on unfired and fired ceramic samples. The results demonstrate the effectiveness of CO2 lasers in engraving ceramics and their potential for various industrial applications. This research provides comprehensive insights into applying CO2 laser technology to ceramic materials. [ABSTRACT FROM AUTHOR]

The present paper investigates flaw strength distributions established using various flexural tests on batches of SiC bar test specimens, namely four-point bending as well as three-point bending tests with different span lengths. Flaw strength is provided by the elemental stress operating on the critical flaw at the fracture of a test specimen. Fracture-inducing flaws and their locations are identified using fractography. A single population of pores was found to dominate the fracture. The construction of diagrams of p-quantile vs. elemental strengths was aimed at assessing the Gaussian nature of flaw strengths. Then, empirical cumulative distributions of strengths were constructed using the normal distribution function. The Weibull distributions of strengths are then compared to the normal reference distributions. The parameters of the Weibull cumulative probability distributions are estimated using maximum likelihood and moment methods. The cumulative distributions of flexural strengths for the different bending tests are predicted from the flaw strength density function using the elemental strength model, and from the cumulative distribution of flexural strength using the Weibull function. Flaw strength distributions that include the weaker flaws that are potentially present in larger test pieces are extrapolated using the p-quantile diagrams. Implications are discussed regarding the pertinence of an intrinsically representative flaw strength distribution, considering failure predictions. Finally, the influence of the characteristics of fracture-inducing flaw populations expressed in terms of flaw strength interval, size, dispersion, heterogeneity, and reproducibility with volume change is examined. [ABSTRACT FROM AUTHOR]

This paper reports experimental investigations on cold plates made from Low-Temperature Co-fired Ceramic (LTCC) technology for liquid cooling of supercomputer microprocessors. LTCC, a ceramic substrate-based technology with lightweight and ease of fabrication for miniaturization of cooling devices, can be a potential alternative to the existing copper cold plates for future three-dimensional stacked chip architectures. LTCC cold plates were fabricated using ceramic substrates whose thermal conductivity was enhanced using thermal vias. They were embedded with microchannels for liquid with different flow configurations. Their thermal performance is compared against copper cold plates. Deionized (DI) water is used as a coolant. Pressure drop and thermal resistance across different cold plates are measured as per water-cooled data center standards (W3 and W4 class). Obtained experimental results show that the tested LTCC cold plates can be used to cool supercomputer processors. It is concluded that LTCC cold plates can be a potential alternative for existing copper cold plates. [ABSTRACT FROM AUTHOR]

In the paper, glass ceramics used as architectural materials were prepared based on lead fuming furnace-slag (LFFS) by a synergistic sinter-crystallization method. The effects of Al2O3 addition on the crystallization phase, crystallization kinetics, and mechanical performance of glass ceramics were investigated. The results showed that the phases of the glass ceramics prepared were composed of gehlenite and wollastonite, and crystallization kinetics analysis showed that bulk crystallization dominated the overall crystallization process in the Al2O3 content range from 2% to 8%. The glass transition temperature and the crystallization peak temperature of the glass ceramics generally increased with the increase in the Al2O3 content. Additionally, the crystalline morphology gradually developed from sheet-like to spherical, while the number of pores increased and the bulk density gradually decreased. When the Al2O3 content was 2%, the bending strength of glass ceramics reached its maximum, 75.1 MPa, corresponding to a bulk density of 2.24 g·cm−3. Owing to the high strength and relatively low bulk density, the sintered glass ceramics appear promising for potential applications in lightweight construction tiles. [ABSTRACT FROM AUTHOR]

Additive manufacturing is very important due to its potential to build components and products using high-performance materials. The filament-based 3D printing of ceramics is investigated, revealing significant developments and advancements in ceramic material extrusion technology in recent years. Researchers employ several typologies of ceramics and binders to achieve fully dense products. The design of the filament and the necessary technological adaptations for 3D printing are fully investigated. From a material perspective, this paper reviews and analyzes the recent developments in additive manufacturing of material-extruded ceramics products, pointing out the performance and properties achieved with different material-binder combinations. The main gaps to be filled and recommendations for future developments in this field are reported. [ABSTRACT FROM AUTHOR]

Copyright of RumeliDE Journal of Language & Literature Research / RumeliDE Dil ve Edebiyat Araştırmaları Dergisi is the property of RumeliDE Uluslararasi Hakemli Dil & Edebiyat Arastirmalari Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Improving fracture toughness, electrical conductivity, and biocompatibility has consistently presented challenges in the development of artificial bone replacement materials. This paper presents a new strategy for creating high-performance, multifunctional composite ceramic materials by doping graphene oxide (GO), which is known to induce osteoblast differentiation and enhance cell adhesion and proliferation into barium calcium zirconate titanate (BCZT) ceramics that already exhibit good mechanical properties, piezoelectric effects, and low cytotoxicity. Using fast hot-pressed sintering under vacuum conditions, (1 − x)(Ba0.85Ca0.15Zr0.1Ti0.9)O3−xGO (0.2 mol% ≤ x ≤ 0.5 mol%) composite piezoelectric ceramics were successfully synthesized. Experimental results revealed that these composite ceramics exhibited high piezoelectric properties (d33 = 18 pC/N, kp = 62%) and microhardness (173.76 HV0.5), meeting the standards for artificial bone substitutes. Furthermore, the incorporation of graphene oxide significantly reduced the water contact angle and enhanced their wettability. Cell viability tests using Cell Counting Kit-8, alkaline phosphatase staining, and DAPI staining demonstrated that the GO/BCZT composite ceramics were non-cytotoxic and effectively promoted cell proliferation and growth, indicating excellent biocompatibility. Consequently, with their superior mechanical properties, piezoelectric performance, and biocompatibility, GO/BCZT composite ceramics show extensive potential for application in bone defect repair. [ABSTRACT FROM AUTHOR]

Ceramic matrix composites (CMCs) are a category of advanced materials which have gained significant interest recently due to their remarkable mechanical and thermal characteristics. These composites are composed of ceramic fibers, particles, or other types of ceramics incorporated in a ceramic matrix and have shown the capability to be implemented in several sectors, including aerospace, energy, and biomedical engineering. This review paper will provide a synopsis of the current scenario and recent progress in CMCs, including materials and processing techniques, characterization methods, and applications. The paper discusses the advantages and limitations of CMCs, recent advancements, and future trends in research. The microstructural and mechanical properties of CMCs are also reviewed, highlighting their potential for various applications. The paper's conclusion delivers a summary of the essential findings and a discussion of future directions for CMC research. [ABSTRACT FROM AUTHOR]

This paper proposes a machining method that uses ultrasonic vibration in the radial direction of the grinding wheel. This method is expected to suppress machining heat because the wheel and workpiece are in intermittent contact with each other. The abrasive grains on the working surface of the wheel act dynamically in the direction of cutting into the workpiece. In this paper, the constant-load grinding of Al2O3 ceramics, a hard and brittle material, was performed. Ductile-mode surfaces were more easily obtained when vibration support was used. The standard deviation of the brightness distribution of the ground surface can be used to evaluate the ductile-mode surface. In this study, the value was less than 16. The results of the measurement of tangential/normal grinding force ratio and the rear-surface temperature of the workpiece confirmed that the values were higher when ductile-mode machining was performed, compared with brittle-mode machining. Furthermore, a vibration-assisted removal model was used to discuss the results of the ductile-mode surfaces, which were more easily obtained when vibration-assisted machining was used. [ABSTRACT FROM AUTHOR]

The paper deals with analyzes of Isothermal Conduction Calorimetry response obtained during the alkaline activation of four types of precursors (metakaolin, slag and two kinds of waste ceramic powders) to geopolymers. The first two precursors are traditionally used, while the latter two are emerging materials and knowledge of their alkaline activation might have high importance in the recycling of Construction and Demolition Waste. The studied precursors differ each to other not only in the chemical composition, but also in the phase composition—the waste ceramic precursors are highly crystalline. It was found that the total reaction heat evolved in the geopolymerization is directly proportional to the amorphous matter content as well as to the compressive strength of the activated product. This finding can be used as fast evaluation tool in searching of new potential geopolymer precursors. The dissolution and polycondensation steps were observed in all experiments and their kinetics was described by Jander's equation. While the rate of dissolution step is not dependent on temperature, the polycondensation has been accelerated by the higher temperature. The level of the rate acceleration was described by apparent activation energy; these findings can be useful in tuning of geopolymers curing procedure. [ABSTRACT FROM AUTHOR]

High‐temperature piezoelectric sensing is usually used in the aerospace, automotive, and power plant fields. High temperature piezoelectric ceramics are considered the key materials in these fields. In this paper, Ca1−x(Ba1/2Sr1/2)xBi2Nb1.985(W3/4Mn1/4)0.015O9 (x = 0.05, 0.10, 0.15 and 0.20) (C1−xBSxBNWM) has been synthesized by a traditional solid state reaction method. The effects of substitution of calcium at the A‐site by barium and strontium on phase evolution and piezoelectric properties of the CaBi2Nb2O9 orthorhombic Aurivillius phases were investigated. The crystal structure of piezoelectric ceramics was characterized by XRD, Rietveld refinement, and Raman spectroscopy. Co‐substitution of barium/strontium (Ba2+/Sr2+) and tungsten/manganese (W6+/Mn4+) resulted in lattice distortion of C1−xBSxBNWM ceramics. The results induce that the tetragonal crystal structure increase with increasing the co‐substitution cations. Isothermal impedance spectroscopy confirmed intrinsic thermally activated conduction in the system. The C1−xBSxBNWM ceramics with x = 0.15 exhibit a very high Curie temperature (TC ∼ 923°C), a reasonable piezoelectric coefficient (d33 = 13.3 pC/N). Remarkably, even after thermal annealing at temperatures up to 800°C, it still retains a high d33 of 13 pC/N. In addition, the C0.85BS0.15BNWM ceramic had a relatively high resistivity (3.82 × 106 Ω·cm, 500°C). The Ca0.85(Ba1/2Sr1/2)0.15Bi2Nb1.985(W3/4Mn1/4)0.015O9 ceramics make possible their application in high‐temperature acceleration transducers. [ABSTRACT FROM AUTHOR]

Copyright of African Archaeological Review is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper studies ceramic samples prepared using traditional ceramic technology also knows as conventional sintering. Samples were prepared from Eu3+ activated fine powders of gadolinium niobate-tantalates GdNb1−yTayO4 (y = 0, 0.7, 1); Eu3+ concentration was x = 0.01, 0.2 and 0.4. Powders were synthesized using nitrate solutions Gd and Eu and niobium and tantalum hydroxides. The hydroxides were coprecipitated from hydrofluoric acid solutions. Full-profile analysis (Rietveld refinement) of XRD (X-ray diffraction) patterns of polycrystals determined the phase composition and refined the parameters of the structure of solid solution phases depending on the Eu concentration. Morphological features of the microstructure have been studied for gadolinium niobate-tantalate ceramics Gd1−xEuxNb1−yTayO4 where y = 0, 0.7, 1 and x = 0.01, 0.2, 0.4. Their mechanical properties have been studied; strength characteristics (Young's modulus, microhardness) and critical stress intensity factor for mode I KIC have been estimated. The compositions and modes for producing ceramics with optimal mechanical properties have been determined. The photoluminescence (PL) has been studied in ceramic solid solutions in the visible range upon excitation by near UV (376 nm). The features of energy transfer between the host of ceramic GdNb1−yTayO4:Eu solid solution (y = 0; 0.7; 1) and 4fn-4fn levels of Eu in concentrations x = 0.01, 0.2 and 0.4 have been established. We have established that concentration quenching of PL in single-phase ceramics Gd1−xEuxNbO4 occurs above Eu concentration x > 0.01 and in ceramics Gd1−xEuxTaO4—at Eu concentration x > 0.2. The sample with the composition Gd0.99Eu0.01NbO4 demonstrated the maximal PL intensity among all other studied samples. The least PL intensity is observed in Gd0.99Eu0.01Nb0.3Ta0.7O4 relative to individual compounds of gadolinium niobates and tantalates, activated with Eu in the same concentration x = 0.01. The significant difference in Stark splitting of levels has been shown for solid solutions based on niobium (Gd1−xEuxNbO4) and tantalum (Gd1−xEuxTaO4). The compositions of ceramic GdNb1−yTayO4:Eu solid solution have been established which have maximum luminance. We have determined that the luminance of some of the studied samples exceeded the luminance of an industrial phosphor based on Y2O3:Eu3+. [ABSTRACT FROM AUTHOR]

Copyright of Kiva is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Kiva is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We have evaluated over fifty materials using small semi–elliptical controlled surface flaws with the Newman–Raju factors. Although occasionally there were nuances and peculiarities, the results were sound and comparable to other methods. So, despite the lengthy discussions and numerous plots in Lubauer et al.'s paper, what is evident is that if one simply follows the guidelines in ASTM C 1421 and the other standards for most ceramics including the SL200B sintered silicon nitride, and polish off the recommended 4.5 to 5 h material, one will obtain the correct results. Excessive indentation forces and excessive material removal to obtain sharp corner, shallow surface cracks are unwise. Removing more than 5 h should only be done to remove lateral cracks. In such cases the Strobl et al. solutions may be useful. These solutions are an interesting alternative to the reputable Newman–Raju factors, but much more experience and verification is needed before they can be accepted. They and the extension of their analysis for precrack angles χ < 70° need to be vetted in a major engineering journal. [ABSTRACT FROM AUTHOR]

The co-achieving of stable colossal permittivity (CP) and low dielectric loss in dielectric materials has been a challenge. In this paper, a transition in CP was observed in V-doped CaCu3Ti4O12 (CCTO) ceramics. The fast high-frequency dielectric relaxation that mainly contributed to CP of CCTO ceramics was greatly suppressed in V-doped CCTO samples. Its relaxation activation energy remained ∼0.10 eV, while its magnitude dropped from thousands in CCTO to dozens in V-doped CCTO. Instead, CP of V-doped CCTO ceramics mainly arose from another slow dielectric relaxation, which appeared in a much lower frequency range. Moreover, this dielectric relaxation gradually turned from a "carrier-dominated" relaxation into a "dipole-dominated" one with the increase in temperature. Its relaxation activation energy also changed from ∼0.06 to 0.42 eV in the meanwhile. These results indicated important roles of multiple point defects and their relating charge transport in CP behaviors. It supported that CP arose from electron trapping behaviors at the edge of double Schottky barriers at grain boundaries. On this basis, suppression of any deep-level point defects was concluded to be a potential clue to achieve both stable CP and sufficiently low dielectric loss in CCTO ceramics and other CP materials. [ABSTRACT FROM AUTHOR]