Ceramic-based dielectric metamaterials

Dielectric metamaterials based on ceramics have attracted considerable in-terest in the past few years owing to their low dielectric loss,simple structure,excellent multifield tunability,and good environmental adaptability.They are considered to be promising alternative to metal-based metamaterials and can lead to a new strategy for the development of passive devices.In this review,the recent progress of ceramic-based dielectric metamaterials in electro-magnetic applications,energy applications,non-Hermitian systems,and natural materials with near-zero or negative refraction are summarized.The design principle and mechanism,as well as manufacturing technologies,are also introduced,and the current development trend of ceramic-based dielectric metamaterials are proposed.

Solid-state electrolytes for solid-state lithium-sulfur batteries:Comparisons,advances and prospects

Compared with other secondary batteries,lithium-sulfur batteries(LSBs)have unparalleled advantages such as high energy density,low cost,etc.In liquid LSB systems,it is extremely easy to cause severe‘‘shuttle effecto and safety issues.Hence,the development of solid-state LSBs(SSLSBs)has been attracting much more attention.As the most essential part of the SSLSBs,the solid-state electrolyte(SSE)has received significant attention from researchers.In this review,we concentrate on discussing the core of SSLSBs,which is the SSE.Moreover,we also highlight the differences in the properties of the different SSEs,which are polymer-based electrolytes and ceramic-based electrolytes.In addition,the challenges and advances in different types of SSEs are also compared and described systematically.Furthermore,the prospects for new SSE systems and the design of effective SSE structures to achieve highperformance SSLSBs are also discussed.Thus,this review is expected to give readers a comprehensive and systematic understanding of SSEs for SSLSBs.

The Strengthening and Toughening Mechanism of Fe-Al/Al_2O_3 Composite Material

By means of different checks and measures, we obserced and analysed the microstructure of Fe-Al/ Al2O3 composite material, We found that not only intragranular nanostructure grains and rod-like crystals but also fine-grained structure of the composite material as well as the bridging of the Fe-Al intermetallics compound contribute to the material＇s strength and toughness, It is shoun that the strengthening and toughening of the Fe- Al/ Al2O3 composite is the joint effect of a multiplicute strengthening and tougheniug mechanism.

Dielectric response of ANb_(2)O_(6)(A = Zn, Co, Mn, Ni) columbite niobates: From microwave to terahertz

In the upcoming 6-generation(6G)revolution,the achievement of low power consumption has become a key objective in research concerning terahertz devices.As an important component of passive devices,there are very few low-loss dielectric ceramics in the terahertz range.To elucidate the mechanism of loss and promote the application of microwave dielectric ceramics for future 6G technology(covering microwave and terahertz frequencies),the terahertz responses of ANb_(2)O_(6)(A=Zn,Co,Mn,and Ni)columbite niobates were studied.The influences of magnetic loss on the Qxf values in the microwave range with different transition metal ions in the A-site were reasonably analyzed.Moreover,due to the weakened magnetic relaxation properties in the terahertz range,the samples all exhibited low loss and approximate transparency,especially for MnNb_(2)O_(6) and NiNb_(2)O_(6)(tano<0.01 and absorption coefficient<10 cm^(-1) below 1.2 THz),which subverted the definition of traditional low-loss microwave dielectric ceramics.Ultimately,based on Mie theory,we designed a prototypical broadband metamaterial reflector to validate the applicability of the ANb_(2)O_(6) system in the terahertz band,which is highly important for the development of terahertz ceramic-based passive devices.