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Microstructural Design and Processing Control of Advanced Ceramics

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Advanced and Functional Ceramics and Glasses".

Deadline for manuscript submissions: closed (10 April 2022) | Viewed by 23002

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Guest Editor
College of Architecture and Environment, Sichuan University, Chengdu 610065, China
Interests: very high cycle fatigue (VHCF) & fracture; mechanics of advanced materials and structures
School of Mechanical Engineering, Chengdu University, Chengdu 610106, China
Interests: dielectric/piezoelectric/ferroelectric materials; flexible electronics; energy harvesting system
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Special Issue Information

Dear Colleagues,

Advanced ceramics are referred to in various parts of the world as technical ceramics, high-tech ceramics, and high-performance ceramics. They represent an important technology which has considerable impact for a large variety of industries, branches, and markets. It is considered an enabling technology which has the potential to deliver high-value contributions for solving the challenges of our future. From a general point of view, the advanced ceramics sector comprises the following categories: 

  • Functional ceramics: Electrical and magnetic ceramics (i.e., dielectrics, piezoelectrics, ferromagnetics), ionic conductors, and superconductive ceramics;
  • Structural ceramics: Monoliths and composites, e.g., oxides, nitrides, carbides, borides, and composite materials based on these materials;
  • Bioceramics, e.g., hydroxyapatite and alumina;
  • Ceramic coatings: Oxides, nitrides, carbides, borides, cermets, and diamond-like coatings, deposited by technologies such as spraying, vapor deposition, and sol–gel coating;
  • Special glasses: processed flat glass, fire-resistant glazing, and glasses for optoelectronics.

First, advanced ceramics tend to lack a glassy component, i.e., they are “basically crystalline”. Second, microstructures are usually highly engineered, meaning that grain sizes, grain shapes, porosity, and phase distributions (for instance, the arrangements of second phases such as whiskers and fibers) can be carefully planned and controlled. Such planning and control require “detailed regulation” of composition and processing. Finally, such advanced ceramics with both well-designed microstructures tend to exhibit unique or superior functional attributes that can be “precisely specified” by careful processing and quality control. Examples include unique electrical properties such as superconductivity or superior mechanical properties, such as enhanced toughness or high-temperature strength.

Because of the attention to microstructural design and processing control, advanced ceramics are often high value-added products. Developments in advanced ceramic processing continue at a rapid pace, constituting what can be considered a revolution in the kind of materials and properties obtained.

Prof. Dr. Qingyuan Wang
Dr. Yu Chen
Guest Editors

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Keywords

  • advanced ceramics
  • chemical composition
  • microstructural design
  • processing control
  • high-performance
  • multifunction

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Published Papers (11 papers)

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Editorial

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6 pages, 2668 KiB  
Editorial
Microstructural Design and Processing Control of Advanced Ceramics
by Yu Chen and Qingyuan Wang
Materials 2023, 16(3), 905; https://doi.org/10.3390/ma16030905 - 17 Jan 2023
Cited by 1 | Viewed by 1513
Abstract
Advanced ceramics are referred to in various parts of the world as technical ceramics, high-tech ceramics, and high-performance ceramics [...] Full article
(This article belongs to the Special Issue Microstructural Design and Processing Control of Advanced Ceramics)
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Research

Jump to: Editorial

10 pages, 5031 KiB  
Article
The Tribological Behaviors in Zr-Based Bulk Metallic Glass with High Heterogeneous Microstructure
by Yubai Ma, Mei Li and Fangqiu Zu
Materials 2022, 15(21), 7772; https://doi.org/10.3390/ma15217772 - 4 Nov 2022
Cited by 2 | Viewed by 1115
Abstract
Microstructural inhomogeneity of bulk metallic glasses (BMGs) plays a significant role in their mechanical properties. However, there is hardly ant research concerning the influence of heterogeneous microstructures on tribological behaviors. Hence, in this research, the tribological behaviors of different microstructural-heterogeneity BMGs sliding in-air [...] Read more.
Microstructural inhomogeneity of bulk metallic glasses (BMGs) plays a significant role in their mechanical properties. However, there is hardly ant research concerning the influence of heterogeneous microstructures on tribological behaviors. Hence, in this research, the tribological behaviors of different microstructural-heterogeneity BMGs sliding in-air were systematically investigated, and the corresponding wear mechanisms were disclosed via analyzing the chemical composition and morphology of the wear track. Higher microstructural-heterogeneity BMGs can possess a better wear resistance both under dry sliding and a 3.5% NaCl solution. The results suggest that microstructural heterogeneity enhancement is a valid strategy to improve the tribological performance of BMGs. Full article
(This article belongs to the Special Issue Microstructural Design and Processing Control of Advanced Ceramics)
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12 pages, 5235 KiB  
Article
Gd/Mn Co-Doped CaBi4Ti4O15 Aurivillius-Phase Ceramics: Structures, Electrical Conduction and Dielectric Relaxation Behaviors
by Daowen Wu, Huajiang Zhou, Lingfeng Li and Yu Chen
Materials 2022, 15(17), 5810; https://doi.org/10.3390/ma15175810 - 23 Aug 2022
Cited by 6 | Viewed by 1540
Abstract
In this work, Gd/Mn co-doped CaBi4Ti4O15 Aurivillius-type ceramics with the formula of Ca1-xGdxBi4Ti4O15 + xGd/0.2wt%MnCO3 (abbreviated as CBT-xGd/0.2Mn) were prepared by the conventional solid-state [...] Read more.
In this work, Gd/Mn co-doped CaBi4Ti4O15 Aurivillius-type ceramics with the formula of Ca1-xGdxBi4Ti4O15 + xGd/0.2wt%MnCO3 (abbreviated as CBT-xGd/0.2Mn) were prepared by the conventional solid-state reaction route. Firstly, the prepared ceramics were identified as the single CaBi4Ti4O15 phase with orthorhombic symmetry and the change in lattice parameters detected from the Rietveld XRD refinement demonstrated that Gd3+ was successfully substituted for Ca2+ at the A-site. SEM observations further revealed that all samples were composed of the randomly orientated plate-like grains, and the corresponding average grain size gradually decreased with Gd content (x) increasing. For all compositions studied, the frequency independence of conductivity observed above 400 °C showed a nature of ionic conduction behavior, which was predominated by the long-range migration of oxygen vacancies. Based on the correlated barrier hopping (CBH) model, the maximum barrier height WM, the dc conduction activation energy Edc, as well as the hopping conduction activation energy Ep were calculated for the CBT-xGd/0.2Mn ceramics. The composition with x = 0.06 was found to have the highest Edc value of 1.87 eV, as well as the lowest conductivity (1.8 × 10−5 S/m at 600 °C) among these compositions. The electrical modules analysis for this composition further illustrated the degree of interaction between charge carrier β increases, with an increase in temperature from 500 °C to 600 °C, and then a turn to decrease when the temperature exceeded 600 °C. The value of β reached a maximum of 0.967 at 600 °C, indicating that the dielectric relaxation behavior at this temperature was closer to the ideal Debye type. Full article
(This article belongs to the Special Issue Microstructural Design and Processing Control of Advanced Ceramics)
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10 pages, 3593 KiB  
Article
High Humidity Response of Sol–Gel-Synthesized BiFeO3 Ferroelectric Film
by Yaming Zhang, Bingbing Li and Yanmin Jia
Materials 2022, 15(8), 2932; https://doi.org/10.3390/ma15082932 - 17 Apr 2022
Cited by 9 | Viewed by 2241
Abstract
In this work, a BiFeO3 film is prepared via a facile sol–gel method, and the effects of the relative humidity (RH) on the BiFeO3 film in terms of capacitance, impedance and current–voltage (IV) are explored. The capacitance [...] Read more.
In this work, a BiFeO3 film is prepared via a facile sol–gel method, and the effects of the relative humidity (RH) on the BiFeO3 film in terms of capacitance, impedance and current–voltage (IV) are explored. The capacitance of the BiFeO3 film increased from 25 to 1410 pF with the increase of RH from 30% to 90%. In particular, the impedance varied by more than two orders of magnitude as RH varied between 30% and 90% at 10 Hz, indicating a good hysteresis and response time. The mechanism underlying humidity sensitivity was analyzed by complex impedance spectroscopy. The adsorption of water molecules played key roles at low and high humidity, extending the potential application of ferroelectric BiFeO3 films in humidity-sensitive devices. Full article
(This article belongs to the Special Issue Microstructural Design and Processing Control of Advanced Ceramics)
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10 pages, 4920 KiB  
Article
Microstructure and Mechanical Properties of Composites Obtained by Spark Plasma Sintering of Ti3SiC2-15 vol.%Cu Mixtures
by Rui Zhang, Biao Chen, Fuyan Liu, Miao Sun, Huiming Zhang and Chenlong Wu
Materials 2022, 15(7), 2515; https://doi.org/10.3390/ma15072515 - 29 Mar 2022
Cited by 12 | Viewed by 1895
Abstract
Method of soft metal (Cu) strengthening of Ti3SiC2 was conducted to increase the hardness and improve the wear resistance of Ti3SiC2. Ti3SiC2/Cu composites containing 15 vol.% Cu were fabricated by Spark Plasma [...] Read more.
Method of soft metal (Cu) strengthening of Ti3SiC2 was conducted to increase the hardness and improve the wear resistance of Ti3SiC2. Ti3SiC2/Cu composites containing 15 vol.% Cu were fabricated by Spark Plasma Sintering (SPS) in a vacuum. The effect of the sintering temperature on the phase composition, microstructure and mechanical properties of the composites was investigated in detail. The as-synthesized composites were thoroughly characterized by scanning electron micrography (SEM), optical micrography (OM) and X-ray diffractometry (XRD), respectively. The results indicated that the constituent of the Ti3SiC2/Cu composites sintered at different temperatures included Ti3SiC2, Cu3Si and TiC. The formation of Cu3Si and TiC originated from the reaction between Ti3SiC2 and Cu, which was induced by the presence of Cu and the de-intercalation of Si atoms Ti3SiC2. OM analysis showed that with the increase in the sintering temperature, the reaction between Ti3SiC2 and Cu was severe, leading to the Ti3SiC2 getting smaller and smaller. SEM measurements illustrated that the uniformity of the microstructure distribution of the composites was restricted by the agglomeration of Cu, controlling the mechanical behaviors of the composites. At 1000 °C, the distribution of Cu in the composites was relatively even; thus, the composites exhibited the highest density, relatively high hardness and compressive strength. The relationships of the temperature, the current and the axial dimension with the time during the sintering process were further discussed. Additionally, a schematic illustration was proposed to explain the related sintering characteristic of the composites sintered by SPS. The as-synthesized Ti3SiC2/Cu composites were expected to improve the wear resistance of polycrystalline Ti3SiC2. Full article
(This article belongs to the Special Issue Microstructural Design and Processing Control of Advanced Ceramics)
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12 pages, 6013 KiB  
Article
Studies on Electron Escape Condition in Semiconductor Nanomaterials via Photodeposition Reaction
by Chen Ye and Yu Huan
Materials 2022, 15(6), 2116; https://doi.org/10.3390/ma15062116 - 13 Mar 2022
Cited by 2 | Viewed by 1875
Abstract
In semiconductor material-driven photocatalysis systems, the generation and migration of charge carriers are core research contents. Among these, the separation of electron-hole pairs and the transfer of electrons to a material’s surface played a crucial role. In this work, photodeposition, a photocatalysis reaction, [...] Read more.
In semiconductor material-driven photocatalysis systems, the generation and migration of charge carriers are core research contents. Among these, the separation of electron-hole pairs and the transfer of electrons to a material’s surface played a crucial role. In this work, photodeposition, a photocatalysis reaction, was used as a “tool” to point out the electron escaping sites on a material’s surface. This “tool” could be used to visually indicate the active particles in photocatalyst materials. Photoproduced electrons need to be transferred to the surface, and they will only participate in reactions at the surface. By reacting with escaped electrons, metal ions could be reduced to nanoparticles immediately and deposited at electron come-out sites. Based on this, the electron escaping conditions of photocatalyst materials have been investigated and surveyed through the photodeposition of platinum. Our results indicate that, first, in monodispersed nanocrystal materials, platinum nanoparticles deposited randomly on a particle’s surface. This can be attributed to the abundant surface defects, which provide driving forces for electron escaping. Second, platinum nanoparticles were found to be deposited, preferentially, on one side in heterostructured nanocrystals. This is considered to be a combination result of work function difference and existence of heterojunction structure. Full article
(This article belongs to the Special Issue Microstructural Design and Processing Control of Advanced Ceramics)
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12 pages, 3125 KiB  
Article
Microstructure and Tribological Properties of Spark-Plasma-Sintered Ti3SiC2-Pb-Ag Composites at Elevated Temperatures
by Rui Zhang, Huiming Zhang and Fuyan Liu
Materials 2022, 15(4), 1437; https://doi.org/10.3390/ma15041437 - 15 Feb 2022
Cited by 6 | Viewed by 1604
Abstract
Ti3SiC2-PbO-Ag composites (TSC-PA) were successfully prepared using the spark plasma sintering (SPS) technique. The ingredient and morphology of the as-synthesized composites were elaborately investigated. The tribological properties of the TSC-PA pin sliding against Inconel 718 alloys disk at room [...] Read more.
Ti3SiC2-PbO-Ag composites (TSC-PA) were successfully prepared using the spark plasma sintering (SPS) technique. The ingredient and morphology of the as-synthesized composites were elaborately investigated. The tribological properties of the TSC-PA pin sliding against Inconel 718 alloys disk at room temperature (RT) to 800 °C were examined in air. The wear mechanisms were argued elaborately. The results showed that the TSC-PA was mainly composed of Ti3SiC2, Pb, and Ag. The average friction coefficient of TSC-PA gradually decreased from 0.72 (RT) to 0.3 (800 °C), with the temperature increasing from RT to 800 °C. The wear rate of TSC-PA showed a decreasing trend, with the temperature rising from RT to 800 °C. The wear rate of Inconel 718 exhibited positive wear at RT and negative wear at elevated temperatures. The tribological property of TSC-PA was related to the tribo-chemistry, and the abrasive and adhesive wear. Full article
(This article belongs to the Special Issue Microstructural Design and Processing Control of Advanced Ceramics)
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23 pages, 4745 KiB  
Article
Effect of Al2TiO5 Content and Sintering Temperature on the Microstructure and Residual Stress of Al2O3–Al2TiO5 Ceramic Composites
by Kunyang Fan, Wenhuang Jiang, Jesús Ruiz-Hervias, Carmen Baudín, Wei Feng, Haibin Zhou, Salvador Bueno and Pingping Yao
Materials 2021, 14(24), 7624; https://doi.org/10.3390/ma14247624 - 11 Dec 2021
Cited by 8 | Viewed by 2734
Abstract
A series of Al2O3–Al2TiO5 ceramic composites with different Al2TiO5 contents (10 and 40 vol.%) fabricated at different sintering temperatures (1450 and 1550 °C) was studied in the present work. The microstructure, crystallite structure, [...] Read more.
A series of Al2O3–Al2TiO5 ceramic composites with different Al2TiO5 contents (10 and 40 vol.%) fabricated at different sintering temperatures (1450 and 1550 °C) was studied in the present work. The microstructure, crystallite structure, and through-thickness residual stress of these composites were investigated by scanning electron microscopy, X-ray diffraction, time-of-flight neutron diffraction, and Rietveld analysis. Lattice parameter variations and individual peak shifts were analyzed to calculate the mean phase stresses in the Al2O3 matrix and Al2TiO5 particulates as well as the peak-specific residual stresses for different hkl reflections of each phase. The results showed that the microstructure of the composites was affected by the Al2TiO5 content and sintering temperature. Moreover, as the Al2TiO5 grain size increased, microcracking occurred, resulting in decreased flexure strength. The sintering temperatures at 1450 and 1550 °C ensured the complete formation of Al2TiO5 during the reaction sintering and the subsequent cooling of Al2O3–Al2TiO5 composites. Some decomposition of AT occurred at the sintering temperature of 1550 °C. The mean phase residual stresses in Al2TiO5 particulates are tensile, and those in the Al2O3 matrix are compressive, with virtually flat through-thickness residual stress profiles in bulk samples. Owing to the thermal expansion anisotropy in the individual phase, the sign and magnitude of peak-specific residual stress values highly depend on individual hkl reflection. Both mean phase and peak-specific residual stresses were found to be dependent on the Al2TiO5 content and sintering temperature of Al2O3–Al2TiO5 composites, since the different developed microstructures can produce stress-relief microcracks. The present work is beneficial for developing Al2O3–Al2TiO5 composites with controlled microstructure and residual stress, which are crucial for achieving the desired thermal and mechanical properties. Full article
(This article belongs to the Special Issue Microstructural Design and Processing Control of Advanced Ceramics)
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11 pages, 2443 KiB  
Article
Effects of Oxide Additives on the Phase Structures and Electrical Properties of SrBi4Ti4O15 High-Temperature Piezoelectric Ceramics
by Shaozhao Wang, Huajiang Zhou, Daowen Wu, Lang Li and Yu Chen
Materials 2021, 14(20), 6227; https://doi.org/10.3390/ma14206227 - 19 Oct 2021
Cited by 5 | Viewed by 2115
Abstract
In this work, SrBi4Ti4O15 (SBT) high-temperature piezoelectric ceramics with the addition of different oxides (Gd2O3, CeO2, MnO2 and Cr2O3) were fabricated by a conventional solid-state reaction route. [...] Read more.
In this work, SrBi4Ti4O15 (SBT) high-temperature piezoelectric ceramics with the addition of different oxides (Gd2O3, CeO2, MnO2 and Cr2O3) were fabricated by a conventional solid-state reaction route. The effects of oxide additives on the phase structures and electrical properties of the SBT ceramics were investigated. Firstly, X-ray diffraction analysis revealed that all these oxides-modified SBT ceramics prepared presented a single SrBi4Ti4O15 phase with orthorhombic symmetry and space group of Bb21m, the change in cell parameters indicated that these oxide additives had diffused into the crystalline lattice of SBT and formed solid solutions with it. The SBT ceramics with the addition of MnO2 achieved a high relative density of up to 97%. The temperature dependence of dielectric constant showed that the addition of Gd2O3 could increase the TC of SBT. At a low frequency of 100 Hz, those dielectric loss peaks appearing around 500 °C were attributed to the space-charge relaxation as an extrinsic dielectric response. The synergetic doping of CeO2 and Cr2O3 could reduce the space-charge-induced dielectric relaxation of SBT. The piezoelectricity measurement and electro-mechanical resonance analysis found that Cr2O3 can significantly enhance both d33 and kp of SBT, and produce a higher phase-angle maximum at resonance. Such an enhanced piezoelectricity was attributed to the further increased orthorhombic distortion after Ti4+ at B-site was substituted by Cr3+. Among these compositions, Sr0.92Gd0.053Bi4Ti4O15 + 0.2 wt% Cr2O3 (SGBT-Cr) presented the best electrical properties including TC = 555 °C, tan δ = 0.4%, kp = 6.35% and d33 = 28 pC/N, as well as a good thermally-stable piezoelectricity that the value of d33 was decreased by only 3.6% after being annealed at 500 °C for 4 h. Such advantages provided this material with potential applications in the high-stability piezoelectric sensors operated below 500 °C. Full article
(This article belongs to the Special Issue Microstructural Design and Processing Control of Advanced Ceramics)
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11 pages, 28589 KiB  
Article
Characterization and Microstructural Evolution of Continuous BN Ceramic Fibers Containing Amorphous Silicon Nitride
by Yang Li, Min Ge, Shouquan Yu, Huifeng Zhang, Chuanbing Huang, Weijia Kong, Zhiguang Wang and Weigang Zhang
Materials 2021, 14(20), 6194; https://doi.org/10.3390/ma14206194 - 18 Oct 2021
Cited by 3 | Viewed by 2656
Abstract
Boron nitride (BN) ceramic fibers containing amounts of silicon nitride (Si3N4) were prepared using hybrid precursors of poly(tri(methylamino)borazine) (PBN) and polycarbosilane (PCS) via melt-spinning, curing, decarburization under NH3 to 1000 °C and pyrolysis up to 1600 °C under [...] Read more.
Boron nitride (BN) ceramic fibers containing amounts of silicon nitride (Si3N4) were prepared using hybrid precursors of poly(tri(methylamino)borazine) (PBN) and polycarbosilane (PCS) via melt-spinning, curing, decarburization under NH3 to 1000 °C and pyrolysis up to 1600 °C under N2. The effect of Si3N4 contents on the microstructure of the BN/Si3N4 composite ceramics was investigated. Series of the BN/Si3N4 composite fibers containing various amounts of Si3N4 from 5 wt% to 25 wt% were fabricated. It was found that the crystallization of Si3N4 could be totally restrained when its content was below 25 wt% in the BN/Si3N4 composite ceramics at 1600 °C, and the amorphous BN/Si3N4 composite ceramic could be obtained with a certain ratio. The mean tensile strength and Young’s modulus of the composite fibers correlated positively with the Si3N4 mass content, while an obvious BN (shell)/Si3N4 (core) was formed only when the Si3N4 content reached 25 wt%. Full article
(This article belongs to the Special Issue Microstructural Design and Processing Control of Advanced Ceramics)
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16 pages, 7902 KiB  
Article
Microstructures and Electrical Conduction Behaviors of Gd/Cr Codoped Bi3TiNbO9 Aurivillius Phase Ceramic
by Huajiang Zhou, Shaozhao Wang, Daowen Wu, Qiang Chen and Yu Chen
Materials 2021, 14(19), 5598; https://doi.org/10.3390/ma14195598 - 26 Sep 2021
Cited by 5 | Viewed by 2038
Abstract
In this work, a kind of Gd/Cr codoped Bi3TiNbO9 Aurivillius phase ceramic with the formula of Bi2.8Gd0.2TiNbO9 + 0.2 wt% Cr2O3 (abbreviated as BGTN−0.2Cr) was prepared by a conventional solid-state reaction route. [...] Read more.
In this work, a kind of Gd/Cr codoped Bi3TiNbO9 Aurivillius phase ceramic with the formula of Bi2.8Gd0.2TiNbO9 + 0.2 wt% Cr2O3 (abbreviated as BGTN−0.2Cr) was prepared by a conventional solid-state reaction route. Microstructures and electrical conduction behaviors of the ceramic were investigated. XRD and SEM detection found that the BGTN−0.2Cr ceramic was crystallized in a pure Bi3TiNbO9 phase and composed of plate-like grains. A uniform element distribution involving Bi, Gd, Ti, Nb, Cr, and O was identified in the ceramic by EDS. Because of the frequency dependence of the conductivity between 300 and 650 °C, the electrical conduction mechanisms of the BGTN−0.2Cr ceramic were attributed to the jump of the charge carriers. Based on the correlated barrier hopping (CBH) model, the maximum barrier height WM, dc conduction activation energy Ec, and hopping conduction activation energy Ep were calculated with values of 0.63 eV, 1.09 eV, and 0.73 eV, respectively. Impedance spectrum analysis revealed that the contribution of grains to the conductance increased with rise in temperature; at high temperatures, the conductance behavior of grains deviated from the Debye relaxation model more than that of grain boundaries. Calculation of electrical modulus further suggested that the degree of interaction between charge carriers β tended to grow larger with rising temperature. In view of the approximate relaxation activation energy (~1 eV) calculated from Z″ and M″ peaks, the dielectric relaxation process of the BGTN−0.2Cr ceramic was suggested to be dominated by the thermally activated motion of oxygen vacancies as defect charge carriers. Finally, a high piezoelectricity of d33 = 18 pC/N as well as a high resistivity of ρdc = 1.52 × 105 Ω cm at 600 °C provided the BGTN−0.2Cr ceramic with promising applications in the piezoelectric sensors with operating temperature above 600 °C. Full article
(This article belongs to the Special Issue Microstructural Design and Processing Control of Advanced Ceramics)
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