Preliminary 3D printing of large inclined-shaped alumina ceramic parts by direct ink writing

Three dimensional(3D)printing technology by direct ink writing(DIW)is an innovative complex shaping technology,possessing advantages of flexibility in fabrication,high efficiency,low cost,and environmental-friendliness.Herein,3D printing of complex alumina ceramic parts via DIW using thermally induced solidification with carrageenan swelling was investigated.The rheological properties of the slurry under different thermally-induced modes were systematically studied.The solidification properties of thermally-induced pastes with varying contents of carrageenan were optimized.The experimental results showed that the optimized paste consisting of 0.4 wt%carrageenan could be rapidly solidified at about 55℃,which could print inclined-plane more than 60°in vertical without support,resulting in better homogeneity of the green body.A nearly pore-free structure was obtained after sintering at 1600℃ for 2 h.

Enhanced thermoelectric performance in Cl-doped BiSbSe_(3) with optimal carrier concentration and effective mass

Possessing inherently low thermal conductivity,BiSbSe_(3) is a promising thermoelectric material for medium temperature.Therefore,to substantially optimize the thermoelectric performance of BiSbSe_(3),researchers mainly focus on the strategies to improve its electrical transport properties.Among these strongly coupled thermoelectric parameters,carrier concentration and effective mass are two intrinsic variables to decisively affect the electrical transport properties.In this work,Cl as a donor dopant is effective to provide extra electrons in n-type BiSbSe_(3),and the carrier concentration and effective mass can be well optimized simultaneously with increasing Cl content owing to the multiple conduction bands in BiSbSe_(3).What’s more,maximum weighted mobility~53 cm^(2)V^(-1)s^(-1)is obtained in Cl-doped BiSbSe_(3),which contributes to a largely enhanced power factor~4.8μW cm^(-1)K^(-2)at room temperature and outperforms other halogen-doped BiSbSe_(3) samples.Finally,combining the significantly enhanced power factor and maintained low thermal conductivity,a maximum ZT~1.0 is achieved in Cl-doped BiSbSe_(3) at 800 K.

Distinct electron and hole transports in SnSe crystals

Thermoelectric materials enable the direct conversion between heat and electricity,providing potential in power generation and cooling applications[1].The energy conversion efficiency is determined by the dimensionless figure of merit ZT=S^(2)σT/κ_(tot),where S is the Seebeck coefficient;σis the electrical conductivity;T is the temperature in Kelvin;κ_(tot)is the total thermal conductivity.