Density-wave instability in α−(BEDT-TTF)2KHg(SCN)4 studied by x-ray diffuse scattering and by first-principles calculations
Loading...
Access rights
openAccess
URL
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
View publication in the Research portal (opens in new window)
View/Open full text file from the Research portal (opens in new window)
Other link related to publication (opens in new window)
Date
2010
Department
Major/Subject
Mcode
Degree programme
Language
en
Pages
1-14
Series
PHYSICAL REVIEW B, Volume 82, issue 13
Abstract
α−(BEDT-TTF)2KHg(SCN)4 develops a density wave ground state below 8 K whose origin is still debated. Here we report a combined x-ray diffuse scattering and first-principles density functional theory study supporting the charge density wave (CDW) scenario. In particular, we observe a triply incommensurate anharmonic lattice modulation with intralayer wave vector components which coincide within experimental errors to the maximum of the calculated Lindhard response function. A detailed study of the structural aspects of the modulation shows that the CDW instability in α−(BEDT-TTF)2KHg(SCN)4 is considerably more involved than those following a standard Peierls mechanism. We thus propose a microscopic mechanism where the CDW instability of the BEDT-TTF layer is triggered by the anion sublattice. Our mechanism also emphasizes the key role of the coupling of the BEDT-TTF and anion layers via the hydrogen bond network to set the global modulation.Description
Keywords
density-wave, first principles, x-ray scattering
Other note
Citation
Foury-Leylekian , P , Pouget , J-P , Lee , Y-J , Nieminen , R M , Ordejon , P & Canadell , E 2010 , ' Density-wave instability in α−(BEDT-TTF)2KHg(SCN)4 studied by x-ray diffuse scattering and by first-principles calculations ' , Physical Review B , vol. 82 , no. 13 , 134116 , pp. 1-14 . https://doi.org/10.1103/PhysRevB.82.134116