A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition techniq...A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition technique. The structural, thermal and electrical properties are studied and presented in detail, which demonstrate that the material is of semiconductor type, orthorhombic structure, with a band gap in the order of 1.56eV and a free carrier concentration of 1.46 × 10^17 cm-3. The thermal conductivity, thermal diffusivity, thermal conduction mode, Seebeck coefficient and electrical conductivity are determined using the photo-thermal deflection technique combined with the Boltzmann transport theory and Cahill＇s model, showing that the AgsSnS6 material has a low thermal conductivity of 3.8 Wm - 1K- 1, high electrical conductivity of 2.4 × 10^5 Sm- 1, Seebeck coefficient of -180μVK-1 and a power factor of 6.9mWK-2m-1, implying that it is more efficient than those obtained in recently experimental investigations for thermoelectric devices.展开更多
A new zero-dimensional（0D） thioborate compound Ba（13）（BS3）6（SnS6）, the first one in the AE/B/Sn/Q（AE=alkali-earth metals; Q=S, Se, Te） family, has been synthesized by conventional high-temperature solid-stat...A new zero-dimensional（0D） thioborate compound Ba（13）（BS3）6（SnS6）, the first one in the AE/B/Sn/Q（AE=alkali-earth metals; Q=S, Se, Te） family, has been synthesized by conventional high-temperature solid-state reaction. It crystallizes in the trigonal space group of R3（No. 148） with a=b=21.4634（6） , c=8.3653（5） , V=3337.4（2） 3, Z=3, Mr=2738.41, Dc=4.088 g/cm3, μ=12.977 mm（-1）, F（000）=3576, the final R=0.0208 and w R=0.0505 with I 〉 2σ（I）, 3.28〈θ〈27.49°, w=1/[σ2（Fo2） ＋（0.0253P）2 ＋ 0.0000P], where P =（Fo2 ＋ 2Fc2）/3, S=1.051,（Δρ）max=0.639 and（Δρ）min=–1.195 e/3. The structure is constructed by discrete [BS3]（3–） trigonal planes and isolated [SnS6]（8–） octahedra with Ba（2＋） cations filled among them. The IR spectrum indicates the presence of lighter element boron. Its optical band gap shown by the UV-Vis-near-IR spectrum is about 2.69 e V, which agrees well with the electronic structure calculation.展开更多
In this article,in-situ scanning electron microscope characterization of the tensile properties of TiB/Ti-2Al-6Sn titanium matrix composite(TMC)was conducted before and after electroshocking treatment(EST).After EST,t...In this article,in-situ scanning electron microscope characterization of the tensile properties of TiB/Ti-2Al-6Sn titanium matrix composite(TMC)was conducted before and after electroshocking treatment(EST).After EST,the tensile strength increased by 113.2 MPa.The effect of EST on the tensile strength and fracture behavior of TiB was investigated using in-situ characterization of the fracture morphology and crack propagation path of the matrix and TiB.Before EST,TiB fracture introduced cracks that extended into the matrix,resulting in material failure.After EST,the refined TiB improved the bearing capacity of the matrix,thereby improving TMC strength.Moreover,after EST,the cracks were introduced into the matrix,and resulting the fracture of matrix first.With an increase in the external load,cracks in the matrix were observed to propagate to TiB,and the refined TiB was fractured,detached,and pulled out,resulting in the formation of pores.Analyzing the propagation path of the main crack after EST showed that the deflection angle of the main crack increased.The micro structure of the fracture surface indicated that the fracture of the matrix was plastic,whereas that of TiB was brittle.After EST,the size and area of the dimples increased,confirming the increase in plasticity.The results revealed that the comprehensive mechanical properties of TiB/Ti-2Al-6Sn improved after EST.Hence,EST is an efficient method for tailoring the micro structures and mechanical properties of TMCs.展开更多
基金Supported by the Scientific Research Deanship of University of Dammam under Grant No 2014264
文摘A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated g/ass （ITO） substrates using a chemical process via the electrodeposition technique. The structural, thermal and electrical properties are studied and presented in detail, which demonstrate that the material is of semiconductor type, orthorhombic structure, with a band gap in the order of 1.56eV and a free carrier concentration of 1.46 × 10^17 cm-3. The thermal conductivity, thermal diffusivity, thermal conduction mode, Seebeck coefficient and electrical conductivity are determined using the photo-thermal deflection technique combined with the Boltzmann transport theory and Cahill＇s model, showing that the AgsSnS6 material has a low thermal conductivity of 3.8 Wm - 1K- 1, high electrical conductivity of 2.4 × 10^5 Sm- 1, Seebeck coefficient of -180μVK-1 and a power factor of 6.9mWK-2m-1, implying that it is more efficient than those obtained in recently experimental investigations for thermoelectric devices.
基金supported by the National Natural Science Foundation of China(21233009,21225104,91422303,21301175 and 21171168)
文摘A new zero-dimensional（0D） thioborate compound Ba（13）（BS3）6（SnS6）, the first one in the AE/B/Sn/Q（AE=alkali-earth metals; Q=S, Se, Te） family, has been synthesized by conventional high-temperature solid-state reaction. It crystallizes in the trigonal space group of R3（No. 148） with a=b=21.4634（6） , c=8.3653（5） , V=3337.4（2） 3, Z=3, Mr=2738.41, Dc=4.088 g/cm3, μ=12.977 mm（-1）, F（000）=3576, the final R=0.0208 and w R=0.0505 with I 〉 2σ（I）, 3.28〈θ〈27.49°, w=1/[σ2（Fo2） ＋（0.0253P）2 ＋ 0.0000P], where P =（Fo2 ＋ 2Fc2）/3, S=1.051,（Δρ）max=0.639 and（Δρ）min=–1.195 e/3. The structure is constructed by discrete [BS3]（3–） trigonal planes and isolated [SnS6]（8–） octahedra with Ba（2＋） cations filled among them. The IR spectrum indicates the presence of lighter element boron. Its optical band gap shown by the UV-Vis-near-IR spectrum is about 2.69 e V, which agrees well with the electronic structure calculation.
基金financially supported by the National Natural Science Foundation of China(No.52271135)the Major Research Plan of the National Natural Science Foundation of China(No.92266102)+5 种基金the Natural Science Foundation of Hubei Province(No.2022CFB492)the Knowledge Innovation Program of Wuhan-Basic Research(No.2022010801010174)the Application Foundation Frontier Project of Wuhan(No.2020010601012171)"Chu Tian Scholar"Project of Hubei Province(No.CTXZ2017-05)the Overseas Expertise Introduction Project for Discipline Innovation(No.B17034)the Innovative Research Team Development Program of Ministry of Education of China(No.IRT_17R83)。
文摘In this article,in-situ scanning electron microscope characterization of the tensile properties of TiB/Ti-2Al-6Sn titanium matrix composite(TMC)was conducted before and after electroshocking treatment(EST).After EST,the tensile strength increased by 113.2 MPa.The effect of EST on the tensile strength and fracture behavior of TiB was investigated using in-situ characterization of the fracture morphology and crack propagation path of the matrix and TiB.Before EST,TiB fracture introduced cracks that extended into the matrix,resulting in material failure.After EST,the refined TiB improved the bearing capacity of the matrix,thereby improving TMC strength.Moreover,after EST,the cracks were introduced into the matrix,and resulting the fracture of matrix first.With an increase in the external load,cracks in the matrix were observed to propagate to TiB,and the refined TiB was fractured,detached,and pulled out,resulting in the formation of pores.Analyzing the propagation path of the main crack after EST showed that the deflection angle of the main crack increased.The micro structure of the fracture surface indicated that the fracture of the matrix was plastic,whereas that of TiB was brittle.After EST,the size and area of the dimples increased,confirming the increase in plasticity.The results revealed that the comprehensive mechanical properties of TiB/Ti-2Al-6Sn improved after EST.Hence,EST is an efficient method for tailoring the micro structures and mechanical properties of TMCs.
