We present a comprehensive investigation into the superconducting properties of L_(a3)Al,a La-based metal with a kagome structure.L_(a3)Al crystallizes in a Ni_(3)Sn-type crystal structure(space group P63/mmc),where t...We present a comprehensive investigation into the superconducting properties of L_(a3)Al,a La-based metal with a kagome structure.L_(a3)Al crystallizes in a Ni_(3)Sn-type crystal structure(space group P63/mmc),where the La atoms form a kagome lattice.Resistivity measurements reveal superconducting transition with T_(c)^(onset)=6.37 K and Tczero=6.18 K.In magnetic susceptibility measurements,the superconducting transition is observed at 6.16 K.The lower and upper critical fields are determined to be 22.17 mT and 6.69 T,respectively.Heat capacity measurements confirm the bulk superconductivity,showing a normalized specific heat change of△Ce/(_(γ)T_(c))=2.16 and an electron-phonon coupling strength ofλ_(ep)=0.92.DFT calculations reveal the intricate band structure of La_(3)Al.The notable specific heat jump,coupled with the electron-phonon coupling strengthλ_(ep),indicates that La_(3)Al exhibits characteristics of an intermediately coupled type-Ⅱsuperconductor.展开更多
The AA5052 aluminum alloy is widely used in automobile and aerospace manufacturing,and with the development of light-weight alloys,it is required that these materials exhibit better mechanical properties.Previous stud...The AA5052 aluminum alloy is widely used in automobile and aerospace manufacturing,and with the development of light-weight alloys,it is required that these materials exhibit better mechanical properties.Previous studies have demonstrated that the addition of Sc to aluminum alloys can improve both the microstructure and properties of the alloys.In this study,the effect of Sc on the Fe-rich phase and properties of the AA5052 aluminum alloy was studied by adding 0%,0.05%,0.2%,and 0.3%Sc.The results show that with the increase of Sc,the coarse needle-like Fe-rich phase gradually transforms into Chinese-script and then nearly spherical particles,reduce the size of Fe-rich phase,and refine the grain with increase of high angle grain boundaries(HAGBs).These microstructure changes enhance the strength of the AA5052 alloy through Sc addition.The ductility of the alloy is obviously improved because the addition of a lower amount of Sc changes the morphology of Fe-rich phase from needle-like into a Chinese-script,and it is subsequently reduced as a result of significant increase in HAGBs with increasing Sc content.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.52272268 and 52250308)the Strategic Priority Research Program and Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Grant No.XDB33010100)+1 种基金the Informatization Plan of Chinese Academy of Sciences(Grant No.CAS-WX2021SF0102)the Synergetic Extreme Condition User Facility(SECUF)。
文摘We present a comprehensive investigation into the superconducting properties of L_(a3)Al,a La-based metal with a kagome structure.L_(a3)Al crystallizes in a Ni_(3)Sn-type crystal structure(space group P63/mmc),where the La atoms form a kagome lattice.Resistivity measurements reveal superconducting transition with T_(c)^(onset)=6.37 K and Tczero=6.18 K.In magnetic susceptibility measurements,the superconducting transition is observed at 6.16 K.The lower and upper critical fields are determined to be 22.17 mT and 6.69 T,respectively.Heat capacity measurements confirm the bulk superconductivity,showing a normalized specific heat change of△Ce/(_(γ)T_(c))=2.16 and an electron-phonon coupling strength ofλ_(ep)=0.92.DFT calculations reveal the intricate band structure of La_(3)Al.The notable specific heat jump,coupled with the electron-phonon coupling strengthλ_(ep),indicates that La_(3)Al exhibits characteristics of an intermediately coupled type-Ⅱsuperconductor.
基金National Natural Science Foundation of China(Nos.52001140,52274363)Guangdong Basic Applied Basic Research Foundation,China(Nos.2022A1515010558,2022A1515011597,2022A1515240065)。
基金National Natural Science Foundation of China(No.52201103)Natural Science Basis Research Plan in Shaanxi Province of China(No.2023JCYB445)Fundamental Research Funds for the Central Universities of CHD(Nos.300102122201,300102122106)。
基金supported by the Key Research&Development Program of Yunnan Province(Grant numbers 202103AA080017,202203AE140011).
文摘The AA5052 aluminum alloy is widely used in automobile and aerospace manufacturing,and with the development of light-weight alloys,it is required that these materials exhibit better mechanical properties.Previous studies have demonstrated that the addition of Sc to aluminum alloys can improve both the microstructure and properties of the alloys.In this study,the effect of Sc on the Fe-rich phase and properties of the AA5052 aluminum alloy was studied by adding 0%,0.05%,0.2%,and 0.3%Sc.The results show that with the increase of Sc,the coarse needle-like Fe-rich phase gradually transforms into Chinese-script and then nearly spherical particles,reduce the size of Fe-rich phase,and refine the grain with increase of high angle grain boundaries(HAGBs).These microstructure changes enhance the strength of the AA5052 alloy through Sc addition.The ductility of the alloy is obviously improved because the addition of a lower amount of Sc changes the morphology of Fe-rich phase from needle-like into a Chinese-script,and it is subsequently reduced as a result of significant increase in HAGBs with increasing Sc content.
