To address the main stumbling-block of bulk metallic glasses （BMGs）, i.e., room temperature brittleness, designing BMG matrix composites has been attracted extensive attention. Up to date, BMG composites in various ...To address the main stumbling-block of bulk metallic glasses （BMGs）, i.e., room temperature brittleness, designing BMG matrix composites has been attracted extensive attention. Up to date, BMG composites in various alloy systems have been successfully developed by forming crystalline phases embedded in the amorphous matrix through either ex-situ or in-situ methods. In this paper, a brief review of our recent work in this topic will be presented and the novel approaches to improving composite formability and mechanical properties will also be highlighted. The main purpose of this manuscript is not to offer a comprehensive review of all the BMG composites, but instead focuses will be placed on illustrating recently developed advanced BMG composites including Fe-based BMG composite with no metalloids, AI-based BMG composite and BMG composites reinforced by the TRIP （transformation-induced plasticity） effects. The basic ideas and related mechanisms underlying the development of these novel BMG composites will be discussed.展开更多
Recently,by intercalating organic ions into bulk FeSe superconductors,two kinds of layered FeSe-based superconductors[(TBA)xFeSe and(CTA)xFeSe]with superconducting transition temperatures(Tc)above 40 K have been disco...Recently,by intercalating organic ions into bulk FeSe superconductors,two kinds of layered FeSe-based superconductors[(TBA)xFeSe and(CTA)xFeSe]with superconducting transition temperatures(Tc)above 40 K have been discovered.Due to the large interlayer distance(~15A),these new layered superconductors have a large resistivity anisotropy analogous to bismuth-based cuprate superconductors.Moreover,remarkable pseudogap behavior well above Tcis revealed by nuclear magnetic resonance(NMR)measurements on77Se nuclei,suggesting a preformed pairing scenario similar to that of cuprates.Here,we report another new kind of organic-ion-intercalated FeSe superconductor,(PY)xFeSe,with a reduced interlayer distance(~10A)compared to(TBA)xFeSe and(CTA)xFeSe.By performing77Se NMR and transport measurements,we observe a similar pseudogap behavior well above Tcof~40 K and a large resistivity anisotropy of~10~4 in(PY)xFeSe.All these facts strongly support a universal pseudogap behavior in these layered FeSe-based superconductors with quasi-two-dimensional electronic structures.展开更多
基金supported in part by the National Natural Science Foundation of China (Nos. 51010001, 51371003, 51001009 and 51271212)111 Project (No. B07003)+2 种基金Program for Changjiang Scholars and Innovative Research Team in Universityfinancial support from the Fundamental Research Funds for the Central Universities (Nos. FRF-SD-12-005A and FRF-TP-11-005A)financial support from the Research Project of State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing (No. 2011Z-13)
文摘To address the main stumbling-block of bulk metallic glasses （BMGs）, i.e., room temperature brittleness, designing BMG matrix composites has been attracted extensive attention. Up to date, BMG composites in various alloy systems have been successfully developed by forming crystalline phases embedded in the amorphous matrix through either ex-situ or in-situ methods. In this paper, a brief review of our recent work in this topic will be presented and the novel approaches to improving composite formability and mechanical properties will also be highlighted. The main purpose of this manuscript is not to offer a comprehensive review of all the BMG composites, but instead focuses will be placed on illustrating recently developed advanced BMG composites including Fe-based BMG composite with no metalloids, AI-based BMG composite and BMG composites reinforced by the TRIP （transformation-induced plasticity） effects. The basic ideas and related mechanisms underlying the development of these novel BMG composites will be discussed.
基金supported by the National Natural Science Foundation of China(Grant Nos.11888101 and 12034004)the National Key R&D Program of China(Grant No.2017YFA0303000)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB25000000)the Anhui Initiative in Quantum Information Technologies(Grant No.AHY160000)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302800)。
文摘Recently,by intercalating organic ions into bulk FeSe superconductors,two kinds of layered FeSe-based superconductors[(TBA)xFeSe and(CTA)xFeSe]with superconducting transition temperatures(Tc)above 40 K have been discovered.Due to the large interlayer distance(~15A),these new layered superconductors have a large resistivity anisotropy analogous to bismuth-based cuprate superconductors.Moreover,remarkable pseudogap behavior well above Tcis revealed by nuclear magnetic resonance(NMR)measurements on77Se nuclei,suggesting a preformed pairing scenario similar to that of cuprates.Here,we report another new kind of organic-ion-intercalated FeSe superconductor,(PY)xFeSe,with a reduced interlayer distance(~10A)compared to(TBA)xFeSe and(CTA)xFeSe.By performing77Se NMR and transport measurements,we observe a similar pseudogap behavior well above Tcof~40 K and a large resistivity anisotropy of~10~4 in(PY)xFeSe.All these facts strongly support a universal pseudogap behavior in these layered FeSe-based superconductors with quasi-two-dimensional electronic structures.
