Journal of the American Ceramic Society Awards Symposium: Journal of the American Ceramic Society Awards Symposium Session I
Sponsored by: ACerS Other
Program Organizers: William Fahrenholtz, Missouri University of Science and Technology
Wednesday 10:20 AM
November 4, 2020
Room: Virtual Meeting Room 14
Location: MS&T Virtual
Session Chair: Bill Fahrenholtz, Missouri University of Science and Technology
10:20 AM
Introductory Comments: Journal of the American Ceramic Society Awards Symposium: William Fahrenholtz1; 1Missouri University of Science and Technology
Introductory Comments
10:25 AM
Direct-Writing of 3D Photonic Crystals with Tunable Terahertz Properties: Qi Li1; 1Southwest Jiaotong University
Terahertz technology (frequencies ranging from 100 GHz to 30 THz) has now received more and more attentions due to its wide applications in various scientific and technical fields. Because of their capability to prohibit the propagation of terahertz irradiation for all directions in their band gaps, three dimensional terahertz photonic crystals (3D-TPCs) with a periodic diamond structure could create specific functionalities. The direct-writing technology had been adopted to create complex 3D-TPCs with various material systems. However, these 3D-TPCs had certain terahertz responses because their composition and structures were fixed after their creation. In this invited presentation, I will talk about our recent work on the development of creation of 3D-TPCs by the direct-writing technology with tunable terahertz properties by structure, composition, and various external stimulations. Novel functions could be integrated to these 3D-TPCs for cutting-edge terahertz technology and other relative technological applications.
10:55 AM
Improvements of Fergusonite-type Microwave Dielectric Ceramics by Ions Substitutions: Di Zhou1; 1Xi'an Jiaotong University
The 5th generation wireless systems (5G) have gradually come to application in recent year due to its apparent advantages compared with the previous 4 G, such as ultra-wideband, ultra-high speed, and ultra-low latency. As a key technique for 5G technology, massive MIMO (multiple input and multiple output) antennas increases sector throughput and capacity density using large numbers of antennas and Multi-user MIMO (MU-MIMO). MgTiO3-CaTiO3, (Ca1+xSm1-x)(Al1-xTix)O4, Li2TiO3 and fergusonite-type LnNbO4 (Ln=La, Nd, Sm etc.) microwave dielectric ceramics systems are potential K20 materials for massive MIMO of mini-station in 5G technology. Among them, fergusonite-type LnNbO4 materials possess low Qf (Q=1/dielectric loss) and large negative TCF (temperature coefficient of resonant frequency) values. In this talk, we will introduce the novel results on the improvements of Qf and TCF values of the fergusonite-type LnNbO4 materials by A and B site substitutions with Bi3+ and V5+ ions.
11:25 AM
Phase Formation and Mechanical Properties of (Mg,Co,Ni,Cu,Zn)O High Entropy Ceramics by Field Assisted Sintering Technology: Fei Chen1; Weichen Hong1; Mingyong Jia1; Qiang Shen1; 1Wuhan University of Technology
High-entropy ceramics are new materials that have only emerged in recent years. Due to its high degree of chaos and special phase structure, high-entropy ceramics have great potential in basic scientific research and practical application. In this presentation, the reaction sequence and mechanical properties of (Mg,Co,Ni,Cu,Zn)O high entropy ceramics that were synthesized using field assisted sintering technology are investigated. The evolution from binary oxide starting powders to a single-phase rock salt structure exhibits a distinct incorporation sequence. MgO, CoO and NiO are the first to be incorporated into the high entropy ceramic followed by CuO and ZnO, which exhibits a different crystal structure. In addition, a trade-off between densification and grain growth result in a maximum in strength (323 MPa) and elastic modulus (108 GPa) after densification at 900 °C.