Symmetry breaking of metal cluster-based strongly correlated systems can give rise to collective phenomena.Here,the twodimensional Nb_(3) cluster compound Nb_(3)Cl_(8) is shown to suffer dramatic symmetry breaking and...Symmetry breaking of metal cluster-based strongly correlated systems can give rise to collective phenomena.Here,the twodimensional Nb_(3) cluster compound Nb_(3)Cl_(8) is shown to suffer dramatic symmetry breaking and electron disproportionation under compression.A structural phase transition from trigonal P–3m1 to monoclinic C2/m is observed near 8 GPa with the three-fold symmetry breaking.Electron disproportionation occurs on Nb_(3) clusters from delocalized Nb^(8/3+)Nb^(8/3+)Nb^(8/3+)to localized Nb^(3+)Nb^(3+)Nb^(2+),which results in a subtle bandgap discontinuity,as evidenced by electrical transport and UV-Vis absorption measurements.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52073003)the Major Program of National Natural Science Foundation of China(Grant No.22090041)+1 种基金the National Key R&D Program of China(Grant No.2018YFA0305900)the Shanghai Sailing Program(Grant No.21YF1454400)。
文摘Symmetry breaking of metal cluster-based strongly correlated systems can give rise to collective phenomena.Here,the twodimensional Nb_(3) cluster compound Nb_(3)Cl_(8) is shown to suffer dramatic symmetry breaking and electron disproportionation under compression.A structural phase transition from trigonal P–3m1 to monoclinic C2/m is observed near 8 GPa with the three-fold symmetry breaking.Electron disproportionation occurs on Nb_(3) clusters from delocalized Nb^(8/3+)Nb^(8/3+)Nb^(8/3+)to localized Nb^(3+)Nb^(3+)Nb^(2+),which results in a subtle bandgap discontinuity,as evidenced by electrical transport and UV-Vis absorption measurements.
