About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
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Neutron and X-ray Scattering in Materials Science
|
Presentation Title |
Understanding the Origin of Kohn Anomalies in Alpha-Uranium |
Author(s) |
Dipanshu Bansal, Aditya Prasad Roy, Naini Bajaj, Ranjan Mittal, P D Babu |
On-Site Speaker (Planned) |
Dipanshu Bansal |
Abstract Scope |
The topology of the Fermi surface controls electronic response of metal, including charge density wave (CDW). A topology conducive to Fermi surface nesting (FSN) allows the electronic susceptibility to diverge and induce a CDW at wave vector qCDW. Kohn extended the implications of
FSN to show that the imaginary part of lattice dynamical susceptibility also responds anomalously for all phonon branches at qCDW — a phenomenon referred to as the Kohn anomaly. However, materials exhibiting multiple Kohn anomalies remain rare. Using first-principles simulations of lattice and electron susceptibility, combined with inelastic neutron scattering measurements we show that α-uranium harbors multiple Kohn anomalies enabled by the combined effect of FSN and “hidden” nesting, i.e., nesting of electronic states above and below the Fermi surface. FSN and hidden nesting lead to a ridgelike feature in real part of electronic susceptibility, allowing interatomic forces to modulate strongly and multiple Kohn anomalies to emerge. |
Proceedings Inclusion? |
Planned: |