Achieving strong microwave absorption capability and wide absorption bandwidth through a combination of high entropy rare earth silicide carbides/rare earth oxides

2020 ◽  
Vol 47 ◽  
pp. 216-222 ◽  
Author(s):  
Heng Chen ◽  
Biao Zhao ◽  
Zifan Zhao ◽  
Huimin Xiang ◽  
Fu-Zhi Dai ◽  
...  
Keyword(s):  
Rare Earth ◽  
Microwave Absorption ◽  
Rare Earth Oxides ◽  
Absorption Bandwidth ◽  
High Entropy ◽  
Rare Earth Silicide

scholarly journals One-step synthesis and electromagnetic absorption properties of high entropy rare earth hexaborides (HE REB6) and high entropy rare earth hexaborides/borates (HE REB6/HE REBO3) composite powders

2020 ◽  
Author(s):  
Weiming Zhang ◽  
Biao Zhao ◽  
Huimin Xiang ◽  
Fu-Zhi Dai ◽  
Shijiang Wu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Magnetic Losses ◽  
Composite Powders ◽  
Absorption Properties ◽  
Absorption Bandwidth ◽  
High Entropy ◽  
Wave Absorption ◽  
Effective Absorption ◽  
Absorbing Materials ◽  
One Step

Abstract Considering the emergence of severe electromagnetic interference problems, it is vital to develop electromagnetic (EM) wave absorbing materials with high dielectric, magnetic loss and optimized impedance matching. However, realizing the synergistic dielectric and magnetic losses in a single phase material is still a challenge. Herein, high entropy (HE) rare earth hexaborides (REB6) powders with coupling of dielectric and magnetic losses were designed and successfully synthesized through a facial one-step boron carbide reduction method, and the effects of high entropy borates intermedia phases on the EM wave absorption properties were investigated. Five HE REB6 ceramics including (Ce0.2Y0.2Sm0.2Er0.2Yb0.2)B6, (Ce0.2Eu0.2Sm0.2Er0.2Yb0.2)B6, (Ce0.2Y0.2Eu0.2Er0.2Yb0.2)B6, (Ce0.2Y0.2Sm0.2 Eu0.2Yb0.2)B6, and (Nd0.2Y0.2Sm0.2Eu0.2 Yb0.2)B6 possess CsCl-type cubic crystal structure, and their theoretical densities range from 4.84 to 5.25 g/cm3. (Ce0.2Y0.2Sm0.2Er0.2 Yb0.2)B6 powders with the average particle size of 1.86 µm were found to possess the best EM wave absorption properties among these hexaborides. The RLmin value of (Ce0.2Y0.2Sm0.2Er0.2Yb0.2)B6 reaches −33.4 dB at 11.5 GHz at thickness of 2 mm; meanwhile, the optimized effective absorption bandwidth (EAB) is 3.9 GHz from 13.6 to 17.5 GHz with a thickness of 1.5 mm. The introduction of HE REBO3 (RE = Ce, Y, Sm, Eu, Er, Yb) as intermediate phase will give rise to the mismatching impedance, which will further lead to the reduction of reflection loss. Intriguingly, the HEREB6/HEREBO3 still possess wide effective absorption bandwidth of 4.1 GHz with the relative low thickness of 1.7 mm. Considering the better stability, low density, and good EM wave absorption properties, HE REB6 ceramics are promising as a new type of EM wave absorbing materials.

LASER SPECTROSCOPY OF RARE EARTH OXIDES

1987 ◽  
Vol 48 (C7) ◽  
pp. C7-611-C7-615
Author(s):  
C. LINTON
Keyword(s):  
Rare Earth ◽  
Laser Spectroscopy ◽  
Rare Earth Oxides

Effect of Rare Earth Oxides on Electrical Properties of Spark Plasma Sintered AlN Ceramics

2015 ◽  
Vol 30 (3) ◽  
pp. 267
Author(s):  
HUANG Lin-Yun ◽  
LI Chen-Hui ◽  
KE Wen-Ming ◽  
SHI Yu-Sheng ◽  
HE Zhi-Yong ◽  
...  
Keyword(s):  
Rare Earth ◽  
Electrical Properties ◽  
Rare Earth Oxides ◽  
Spark Plasma

A glance on rare earth oxides: importance, reserves, demand, applications, critical uncertainties, global economy, and zeta potential characterization

2020 ◽  
Vol 05 ◽  
Author(s):  
Silas Santos ◽  
Orlando Rodrigues ◽  
Letícia Campos
Keyword(s):  
Rare Earth ◽  
Zeta Potential ◽  
Sample Preparation ◽  
Rare Earths ◽  
Smart Materials ◽  
Global Economy ◽  
Materials Science ◽  
Functional Materials ◽  
Rare Earth Oxides ◽  
Interparticle Forces

Background: Innovation mission in materials science requires new approaches to form functional materials, wherein the concept of its formation begins in nano/micro scale. Rare earth oxides with general form (RE2O3; RE from La to Lu, including Sc and Y) exhibit particular proprieties, being used in a vast field of applications with high technological content since agriculture to astronomy. Despite of their applicability, there is a lack of studies on surface chemistry of rare earth oxides. Zeta potential determination provides key parameters to form smart materials by controlling interparticle forces, as well as their evolution during processing. This paper reports a study on zeta potential with emphasis for rare earth oxide nanoparticles. A brief overview on rare earths, as well as zeta potential, including sample preparation, measurement parameters, and the most common mistakes during this evaluation are reported. Methods: A brief overview on rare earths, including zeta potential, and interparticle forces are presented. A practical study on zeta potential of rare earth oxides - RE2O3 (RE as Y, Dy, Tm, Eu, and Ce) in aqueous media is reported. Moreover, sample preparation, measurement parameters, and common mistakes during this evaluation are discussed. Results: Potential zeta values depend on particle characteristics such as size, shape, density, and surface area. Besides, preparation of samples which involves electrolyte concentration and time for homogenization of suspensions are extremely valuable to get suitable results. Conclusion: Zeta potential evaluation provides key parameters to produce smart materials seeing that interparticle forces can be controlled. Even though zeta potential characterization is mature, investigations on rare earth oxides are very scarce. Therefore, this innovative paper is a valuable contribution on this field.

High‐entropy ferroelastic rare‐earth tantalite ceramic: (Y 0.2 Ce 0.2 Sm 0.2 Gd 0.2 Dy 0.2 )TaO 4

2021 ◽  
Author(s):  
Wang Jun ◽  
Fushuo Wu ◽  
Zou Ruoan ◽  
Wu Yueshu ◽  
Gan Mengdi ◽  
...  
Keyword(s):  
Rare Earth ◽  
High Entropy

scholarly journals Synthesis, characterization, and single-crystal growth of a high-entropy rare-earth pyrochlore oxide

2020 ◽  
Vol 4 (10) ◽  
Author(s):  
Candice Kinsler-Fedon ◽  
Qiang Zheng ◽  
Qing Huang ◽  
Eun Sang Choi ◽  
Jiaqiang Yan ◽  
...  
Keyword(s):  
Rare Earth ◽  
Crystal Growth ◽  
Single Crystal ◽  
Single Crystal Growth ◽  
High Entropy ◽  
Pyrochlore Oxide
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