Dynamical Bond Formation in KNi2Se2
[1];
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[3]
- Johns Hopkins University, Baltimore, MD (United States); Colorado State University, Fort Collins, CO (United States)
- Johns Hopkins University, Baltimore, MD (United States); California State University (CalState), Fullerton, CA (United States)
- Johns Hopkins University, Baltimore, MD (United States)
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Argonne National Laboratory (ANL), Argonne, IL (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Argonne National Laboratory (ANL), Argonne, IL (United States); University of Bordeaux, Pessac (France)
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 zig-zag 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.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States); Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source (APS); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- David and Lucile Packard Foundation; USDOE; USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
- Grant/Contract Number:
- 89233218CNA000001; AC02-06CH11357; AC05-00OR22725; AC52-06NA25396; FG02-08ER46544
- OSTI ID:
- 1869636
- Report Number(s):
- LA-UR-22-24117
- Journal Information:
- Zeitschrift fuer Anorganische und Allgemeine Chemie, Journal Name: Zeitschrift fuer Anorganische und Allgemeine Chemie Journal Issue: 15 Vol. 648; ISSN 0044-2313
- Publisher:
- WileyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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