Highly dense 0.3CaCeNbWO₈‐0.7LaMnO₃ composite ceramics fabricated by cold sintering process

Abstract

The cold sintering process (CSP) has been used for fabricating functional ceramics at a low sintering temperature. In this study, highly dense 0.3CaCeNbWO8‐0.7LaMnO3 composite ceramics have been successfully fabricated by CSP. The phase structure, microstructure, and electrical properties of composite ceramics have been investigated. The composite ceramic is mainly composed of a tetragonal CaCeNbWO8 phase with scheelite structure and an orthorhombic LaMnO3 phase with perovskite structure. The relative density of composite ceramic is 94.5%, and is higher than that of single phase ceramic. The resistivity of composite ceramic exhibits negative temperature coefficient characteristics, with an aging coefficient less than 2%. Such a sintering methodology is of great significance, since it provides a feasible idea for preparing composite ceramics.

Photoluminescence and conductive properties of CaEuNbMoO8 solid‐solution ceramics

“…From the slope of the ln ρ versus 1000/ T curve, it can be calculated that the activation energy of the sample is 1.462 eV, which indicates that the polaron jump needs to overcome the large energy barrier. From the calculated B value, it can be seen that CENMO has a higher B value than that of similar material, 14,15,22 as shown in Table 2. Higher B values are more sensitive to variation of temperature, providing more accurate and smaller variation in temperature measurement 50 .…”

“…18,19 On the other hand, the transfer of polaron changes the concentration of electrons. 20 In addition, solid solution ceramics based on the Ca-Ln-Nb-M-O can be modulated in various ways to improve their electrical conductivity, such as adjusting the content of solid solution components, 14 doping with rare earth ions, 21 optimizing the sintering process, and compounding with low resistance phases, 22 all of which can effectively increase the practical application of these ceramic materials.…”

Polycrystalline thermosensitive ceramic oxides in CaCeNbWO8: Density, texture, and thermal aging stability

“…The XPS spectrum of CeO 2 raw powder was used to more accurately determine the binding energies of Ce ions, which is similar to our previous work. 32 Figure 6A presents the XPS spectra of the Ce 3d core levels for all oxides. Compared with the binding energies of CeO 2 , ν 0 (∼882.1 eV, ∼881.2 eV), ν 0 ť (∼900.7 eV, ∼899.6 eV), ν 1 ť (∼906.8 eV, ∼906.9 eV), and ν 2 ť (∼916.1 eV, ∼916.0 eV) in pressureless-sintered and pressure-sintered ceramics are labeled as the +4 valence state of Ce, and μ 0 (∼880.5 eV), μ 1 (∼884.9 eV, ∼885.1 eV), μ 0 ť (∼898.3 eV) and μ 1 ť (∼903.2 eV, ∼903.7 eV) are confirmed as the +3 valence state of Ce.…”

Fast response and high stability Mn–Co–Ni–Al–O NTC microbeads thermistors

“…Ceramic are used in a wide range of applications such as temperature sensors, controllers, infrared detectors, voltage regulators, and delay devices due to their many excellent properties and negative temperature coefficient 1‐2 . Moreover, ternary spinel compounds, i.e.…”

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Ceramic are used in a wide range of applications such as temperature sensors, controllers, infrared detectors, voltage regulators, and delay devices due to their many excellent properties and negative temperature coefficient. [1][2] Moreover, ternary spinel compounds, i.e. (Mn 3x-y Co x Ni y )O 4 (MCN), render promising electrical properties due to their easy fabrication and outstanding properties.

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