Dynamical Bond Formation in KNi2Se2
SUCHOMEL, Matthew
Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
Advanced Photon Source [ANL] [APS]
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Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
Advanced Photon Source [ANL] [APS]
Language
en
Article de revue
This item was published in
Journal of Inorganic and General Chemistry / Zeitschrift für anorganische und allgemeine Chemie. 2022, vol. 648, n° 15, p. e202200042 (7 p.)
Wiley-VCH Verlag
English Abstract
Emphanisis, or the appearance out of nothing, has been used to describe the phenomena of spontaneous atom off-centering and dipole formation at elevated temperatures in lead chalcogenides. Here, we provide spectroscopic ...Read more >
Emphanisis, or the appearance out of nothing, has been used to describe the phenomena of spontaneous atom off-centering and dipole formation at elevated temperatures in lead chalcogenides. Here, we provide spectroscopic evidence of spontaneous formation of metal-metal bonds above T ~ 50 K in the layered metal KNi2Se2. These bonds form zigzag chains that lower the local symmetry from tetragonal to monoclinic. Energy-resolved pair distribution function measurements exclude a pure phonon origin of our observations, and instead imply the existence of extra, slowly fluctuating, Ni-Ni bonds above T = 50 K. Density functional theory calculations support this lower symmetry configuration as an instability of tetragonal KNi2Se2. We thus demonstrate that the phenomena of emphansis is not limited to local electric dipole formation, but can also be driven by the formation of metal-metal bonds.Read less <
Origin
Hal imported