Chelate complex assisted cold sintering for spinel ceramics

Funahashi, Shuichi; Kobayashi, Eigo; Kimura, Masahiko; Shiratsuyu, Kosuke; Randall, Clive A.

doi:10.2109/jcersj2.19140

Cited by 23 publications

(7 citation statements)

References 15 publications

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“…In recent years, the cold sintering process (CSP), as an energyefficient sintering technology, has emerged. The CSP is a technique according to which the densified ceramics or metals are sintered at low temperatures, typically below 300 • C and high pressure, with the aid of a transient solvent [12][13][14][15]. In the typical cold sintering process, the introduction of a certain amount of liquid is indispensable.…”

Section: Introductionmentioning

confidence: 99%

Preparation of Densified Fine-Grain High-Frequency MnZn Ferrite Using the Cold Sintering Process

Ying

et al. 2023

Materials

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The densified MnZn ferrite ceramics were prepared using the cold sintering process under pressure, with an acetate ethanol solution used as the transient solvent. The effects of the transient solvent, the pressure and annealing temperature on the density, and the micromorphology and magnetic properties of the sintered MnZn ferrites were studied. The densified MnZn ferrite was obtained using the cold sintering process and its relative density reached up to 85.4%. The transient solvent and high pressure are essential to the cold sintering process for MnZn ferrite. The annealing treatment is indispensable in obtaining the sample with the higher density. The relative density was further increased to 97.2% for the sample annealed at 950 °C for 6 h. The increase in the annealing temperature reduces the power loss at high frequencies.

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Section: Introductionmentioning

confidence: 99%

Preparation of Densified Fine-Grain High-Frequency MnZn Ferrite Using the Cold Sintering Process

Ying

et al. 2023

Materials

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“…Funahashi et al applied a chelating complex for the densification of spinelbased ferrites. 35 Also, recently, Santha et al used EDTA as the sintering aid to densify the Li 2 TiO 3 -PTFE composites. 36 In the recent past, on account of the lower polarizability of F − (1.62 Å 3 ) than that of an O 2− ion (2.01 Å 3 ), researchers have more focused on fluoride-based systems to take advantage of CSP for promising microwave dielectric ceramics.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Cold-sintered hydroxyapatite (HA) having high density was prepared by Shen et al and Hassan et al without any added solvent. Funahashi et al applied a chelating complex for the densification of spinel-based ferrites . Also, recently, Santha et al used EDTA as the sintering aid to densify the Li 2 TiO 3 -PTFE composites …”

Section: Introductionmentioning

confidence: 99%

Water and SnF₂ Assisted Ultralow-Temperature Sintering of Mechanically Tough Y₃Fe₅O₁₂ Composites for Magneto-Dielectric Antennas

Madhuri

Subodh

2023

ACS Appl. Electron. Mater.

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Recently, the cold sintering process (CSP) has gained worldwide recognition from the scientific community as a green and innovative fabrication technique due to the substantial reduction of processing energy, time, and cost. The present work reports the preparation, fabrication, and properties of (1 – x)Y3Fe5O12–xSnF2 (x = 0.2, 0.3, 0.4, 0.5 volume fraction) ceramic composites for the first time through the cold sintering process under 150 °C, by applying 300 MPa uniaxial pressure for 30 min. The evolved microstructures of the cold-sintered composites suggest enhanced densification with increasing SnF2 concentration. The evolution of the microstructure, consequent densification, and hardness of the composites can be due to the combined effect of water as a transient solvent and the relatively low melting point of SnF2. The main mechanism behind the densification in the SnF2-based system can be the liquid phase formation followed by pressure solution creep and plastic deformation. At the optimum additive concentration, the measured microhardness of the composite is around 4.7 GPa and its moisture absorption lies below 0.1%. The (1 – x)YIG–xSnF2 ceramics have relative permittivity (εr) in the range of 7.1–11.3 and loss tangent of the order of 10–2 at a frequency of 900 MHz. Further, the real part of permeability and the corresponding loss tangent lie below 2 and 10–1, respectively, at 900 MHz. Herein, a microstrip patch antenna (MPA) is designed, simulated, and fabricated using the 0.5YIG–0.5SnF2 composite, which shows excellent performance at 5.29 GHz with a return loss of −17.9 dB and an impedance bandwidth of 780 MHz. Hence, cold sintering using SnF2-based additives is considered a sustainable, energy-efficient, and cost-effective tool for the densification of magneto-dielectric materials.

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“…To improve the incompatible ceramic-polymer interphase, several workers have added coupling agents or other surface-active agents such as organo-titanates and organometallic chelating agents . Funahashi et al have obtained high densification in spinel-based ceramics by chelate complex assisted CSP. Ndayishimiye et al studied the role of metal-organic chelate Zn(AcAc) 2 · x H 2 O on cold-sintering of ZnO .…”

Section: Introductionmentioning

confidence: 99%

Ethylenediaminetetraacetic Acid (EDTA) Assisted Single Step Densification of Li₂TiO₃/PTFE Composites at Ultralow Sintering Temperature to Realize a High-Performance Ku-Band Antenna

Narayanaiyer

Mohanan

Nazeemabeevi

et al. 2022

ACS Appl. Electron. Mater.

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In the last few decades, extensive research has been focused on the ever-increasing demand for energy-efficient materials and technologies in consumer electronics. The low-weight, low-cost, environmentally safe Li-based ceramics are widely investigated as potential materials for Li-ion batteries and low-temperature cofired ceramics (LTCC). In the present work, we combine high volume fractions of Li2TiO3 (LT) ceramic with incredibly versatile polytetrafluoroethylene (PTFE) to synthesize thermally stable, low-loss dielectrics at ultralow temperatures (<150 °C) in a single step without any additional transient liquid phase in a very short time, and the effect of different wt % of ethylenediaminetetraacetic acid (EDTA), which is a chelating agent, on the densification, microstructure, thermal, and broadband dielectric properties of these composites has been studied. X-ray photoelectron and FTIR spectroscopic analyses were used to explain the densification mechanism in these composites. The presence of the OH– ion on the surface of LT and manipulation of the ceramic-polymer interphase by EDTA are significant in the densification of LT-PTFE composites. A cylindrical prototype dielectric resonator antenna (CDRA) was designed, simulated, and fabricated with the 0.7LT-0.3PTFE-5EDTA composite having excellent thermal and dielectric properties, and antenna properties were experimentally verified. The return loss, input impedance, and radiation pattern of the CDRA were examined, and the experimental results match reasonably well with simulated results. This study shows that the 0.7LT-0.3PTFE-5EDTA composite is a potential candidate for the fabrication of an economical, low-loss, lightweight, easy-to-fabricate, wide bandwidth CDRA for telecommunication applications in the Ku-band. Further, it is possible to achieve enhanced bandwidth and gain, by varying the compositions of these composites.

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Chelate complex assisted cold sintering for spinel ceramics

Cited by 23 publications

References 15 publications

Preparation of Densified Fine-Grain High-Frequency MnZn Ferrite Using the Cold Sintering Process

Preparation of Densified Fine-Grain High-Frequency MnZn Ferrite Using the Cold Sintering Process

Water and SnF₂ Assisted Ultralow-Temperature Sintering of Mechanically Tough Y₃Fe₅O₁₂ Composites for Magneto-Dielectric Antennas

Ethylenediaminetetraacetic Acid (EDTA) Assisted Single Step Densification of Li₂TiO₃/PTFE Composites at Ultralow Sintering Temperature to Realize a High-Performance Ku-Band Antenna

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Chelate complex assisted cold sintering for spinel ceramics

Cited by 23 publications

References 15 publications

Preparation of Densified Fine-Grain High-Frequency MnZn Ferrite Using the Cold Sintering Process

Preparation of Densified Fine-Grain High-Frequency MnZn Ferrite Using the Cold Sintering Process

Water and SnF2 Assisted Ultralow-Temperature Sintering of Mechanically Tough Y3Fe5O12 Composites for Magneto-Dielectric Antennas

Ethylenediaminetetraacetic Acid (EDTA) Assisted Single Step Densification of Li2TiO3/PTFE Composites at Ultralow Sintering Temperature to Realize a High-Performance Ku-Band Antenna

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Product

Resources

About

Water and SnF₂ Assisted Ultralow-Temperature Sintering of Mechanically Tough Y₃Fe₅O₁₂ Composites for Magneto-Dielectric Antennas

Ethylenediaminetetraacetic Acid (EDTA) Assisted Single Step Densification of Li₂TiO₃/PTFE Composites at Ultralow Sintering Temperature to Realize a High-Performance Ku-Band Antenna