Oxygen vacancy regulation and its high frequency response mechanism in microwave ceramics

Zhang, Bowen; Li, Lingxia; Luo, Weijia

doi:10.1039/c8tc03936d

Cited by 55 publications

(16 citation statements)

References 44 publications

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“…33 Meanwhile, the substitution of donor Nb 5+ for Ti 4+ provides excess electrons, which contributes to inhibiting the formation of oxygen vacancies. 34 The decreased concentration of oxygen vacancies inhibits mass transportation during the sintering process, resulting in a decreased grain size. 35 The decreased average grain size contributes to the improvement of BDS.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Aliovalent Doping Engineering for A- and B-Sites with Multiple Regulatory Mechanisms: A Strategy to Improve Energy Storage Properties of Sr_0.7Bi_0.2TiO₃-Based Lead-Free Relaxor Ferroelectric Ceramics

Zhao

Fang

Zhang

et al. 2021

ACS Appl. Mater. Interfaces

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Sr 0.7 Bi 0.2 TiO 3 (SBT) is a promising pulse energy storage material due to minor hysteresis, but its low maximum polarization (P max ) is bad for energy storage. K + −Bi 3+ defect pairs were introduced into the A-site of SBT to obtain Sr 0.35 Bi 0.35 K 0.25 TiO 3 (SBKT) with larger P max . Through firstprinciples calculations, we determined that the introduction of defect pairs destroys the paraelectric order phase and increases local polarization, resulting in more and larger polar nanoregion (PNR) formation. On this basis, doping NaNbO 3 (NN) in A-and B-sites of SBKT increases the cationic disorder and ferroelectric destabilization, further destroying the long-range order structure and forming more PNRs with smaller sizes. This enhances relaxation and decreases remnant polarization, and the broadened dielectric peak enables 0.85SBKT−0.15NN to meet the X7R specification. Furthermore, the decreased grain size and oxygen vacancy, increased thermal conductivity, and weakened local electric field (simulated by COMSOL) increase the dielectric breakdown strength (BDS). As a result, 0.95SBKT−0.05NN exhibits a high energy storage density (W) of 2.45 J/cm 3 with a high efficiency of 93.1%, a high pulsed discharge energy density of 2.1 J/cm 3 , and a high power density of 54.1 MW/cm 3 at 220 kV/cm. The energy storage properties show excellent stability of temperature (−55 to 150 °C), frequency (10−500 Hz), and cycling (10 5 cycles). Notably, for the pulse charge−discharge properties, 0.95SBKT−0.05NN shows great fatigue resistance during 10 5 cycles under 25 and 150 °C, accompanied by excellent thermal stability. Moreover, the BDS and P max of 0.95SBKT−0.05NN sintered in O 2 further enhance. A higher W of 2.92 J/cm 3 with a high efficiency of 89% at 250 kV/cm is achieved. Therefore, 0.95SBKT−0.05NN shows great application potential for pulse energy storage. In this work, we provide a novel strategy and systematic in-depth study for improving the energy storage properties of SBT.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Aliovalent Doping Engineering for A- and B-Sites with Multiple Regulatory Mechanisms: A Strategy to Improve Energy Storage Properties of Sr_0.7Bi_0.2TiO₃-Based Lead-Free Relaxor Ferroelectric Ceramics

Zhao

Fang

Zhang

et al. 2021

ACS Appl. Mater. Interfaces

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“…In Ti-containing systems, it was commonly found that the reduction of Ti 4+ ions brought about the deterioration of Qf values. [31][32][33] Similarly, the electron ionized from oxygen vacancy during the sintering process would be bonded to V 5+ . The defect equations were written as follows:…”

Section: Resultsmentioning

confidence: 99%

“…The Qf reached 56 660 GHz at 740°C, was reduced with an increase in ST. In Ti‐containing systems, it was commonly found that the reduction of Ti 4+ ions brought about the deterioration of Qf values 31‐33 . Similarly, the electron ionized from oxygen vacancy during the sintering process would be bonded to V 5+ .…”

Section: Resultsmentioning

confidence: 99%

SrZnV₂O₇: A low‐firing microwave dielectric ceramic with high‐quality factor

Chen

Zhang

et al. 2021

J Am Ceram Soc

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The explosive advances in modern communication have provoked huge requirements for microwave devices with superior performance. To satisfy the criteria for device fabrication, microwave dielectric ceramics should own a proper dielectric constant (ε r ), a high-quality factor (Qf), and a nearzero temperature coefficient of resonant frequency (τ f ). [1][2][3] Recently, low-temperature co-fired ceramic (LTCC) technology has gained considerable attention for it can effectively lessen the volume of components, allowing for realizing miniaturization, integration, and modularization of devices. In LTCC, ceramics need to be co-fired with metal electrodes (e.g., Ag), which requires a low sintering temperature (ST) (<961°C, the melting point of Ag) and chemical compatibility with electrodes. [4][5][6] There are numerous ceramic systems developed with desirable properties, such as MgO-

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“…The concentration of oxygen vacancy, relative density, and decrease in damping behavior would influence the Q×f value of Li 2 ZnTi 3 O 8 -x wt% Nb 2 O 5 [270]. To trace the dielectric response of lattice vibration, the response process of dielectric loss in Li 2 ZnTi 3-x M x O 8 (M = Al 3+ , Nb 5+ , (Al 0.5 Nb 0.5 ) 4+ , (Zn 1/3 Nb 2/3 ) 4+ , and (Li 1/4 Nb 3/4 ) 4+ ) was discussed systematically containing the conduction loss and lattice vibration loss [271]. The conduction loss which acts at frequency lower than terahertz is neglectful by researchers concentrating on MWDCs, while AC impedance analysis was used to identify the effect of dopants and the mechanism of conduction loss in this system.…”

Section: Rock-salt Structurementioning

confidence: 99%

The latest process and challenges of microwave dielectric ceramics based on pseudo phase diagrams

et al. 2021

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The explosive process of 5G communication evokes the urgent demand of miniaturized and integrated dielectric ceramics filter. It is a pressing need to advance the development of dielectric ceramics utilization of emerging technology to design new materials and understand the polarization mechanism. This review provides the summary of the study of microwave dielectric ceramics (MWDCs) sintered higher than 1000 from 2010 up to now, °C with the purpose of taking a broad and historical view of these ceramics and illustrating research directions. To date, researchers endeavor to explain the structure-property relationship of ceramics with multitude of approaches and design a new formula or strategy to obtain excellent microwave dielectric properties. There are variety of factors that impact the permittivity, dielectric loss, and temperature stability of dielectric materials, covering intrinsic and extrinsic factors. Many of these factors are often intertwined, which can complicate new dielectric material discovery and the mechanism investigation. Because of the various ceramics systems, pseudo phase diagram was used to classify the dielectric materials based on the composition. In this review, the ceramics were firstly divided into ternary systems, and then brief description of the experimental probes and complementary theoretical methods that have been used to discern the intrinsic polarization mechanisms and the origin of intrinsic loss was mentioned. Finally, some perspectives on the future outlook for high-temperature MWDCs were offered based on the synthesis method, characterization techniques, and significant theory developments.

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Oxygen vacancy regulation and its high frequency response mechanism in microwave ceramics

Abstract: This article reports a new research method for oxygen vacancy regulation in microwave ceramics and its high frequency response mechanism.

Cited by 55 publications

References 44 publications

Aliovalent Doping Engineering for A- and B-Sites with Multiple Regulatory Mechanisms: A Strategy to Improve Energy Storage Properties of Sr_0.7Bi_0.2TiO₃-Based Lead-Free Relaxor Ferroelectric Ceramics

Aliovalent Doping Engineering for A- and B-Sites with Multiple Regulatory Mechanisms: A Strategy to Improve Energy Storage Properties of Sr_0.7Bi_0.2TiO₃-Based Lead-Free Relaxor Ferroelectric Ceramics

SrZnV₂O₇: A low‐firing microwave dielectric ceramic with high‐quality factor

The latest process and challenges of microwave dielectric ceramics based on pseudo phase diagrams

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Oxygen vacancy regulation and its high frequency response mechanism in microwave ceramics

Abstract: This article reports a new research method for oxygen vacancy regulation in microwave ceramics and its high frequency response mechanism.

Cited by 55 publications

References 44 publications

Aliovalent Doping Engineering for A- and B-Sites with Multiple Regulatory Mechanisms: A Strategy to Improve Energy Storage Properties of Sr0.7Bi0.2TiO3-Based Lead-Free Relaxor Ferroelectric Ceramics

Aliovalent Doping Engineering for A- and B-Sites with Multiple Regulatory Mechanisms: A Strategy to Improve Energy Storage Properties of Sr0.7Bi0.2TiO3-Based Lead-Free Relaxor Ferroelectric Ceramics

SrZnV2O7: A low‐firing microwave dielectric ceramic with high‐quality factor

The latest process and challenges of microwave dielectric ceramics based on pseudo phase diagrams

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Aliovalent Doping Engineering for A- and B-Sites with Multiple Regulatory Mechanisms: A Strategy to Improve Energy Storage Properties of Sr_0.7Bi_0.2TiO₃-Based Lead-Free Relaxor Ferroelectric Ceramics

Aliovalent Doping Engineering for A- and B-Sites with Multiple Regulatory Mechanisms: A Strategy to Improve Energy Storage Properties of Sr_0.7Bi_0.2TiO₃-Based Lead-Free Relaxor Ferroelectric Ceramics

SrZnV₂O₇: A low‐firing microwave dielectric ceramic with high‐quality factor