X-ray observation of 2$k_{\rm F}$ and 4$k_{\rm F}$ charge orderings in (TMTTF)$_2$Re0$_4$ and (TMTTF)$_2$SCN associated with anion orderings

Y. Nogami; T. Nakamura

doi:doi:10.1051/jp4:20020381

Issue		J. Phys. IV France Volume 12, Number 9, November 2002


Page(s)		145 - 148
DOI		https://doi.org/10.1051/jp4:20020381

J. Phys. IV France 12 (2002) Pr9-145
DOI: 10.1051/jp4:20020381

X-ray observation of 2 $k_{\rm F}$ and 4 $k_{\rm F}$ charge orderings in (TMTTF) ₂Re0 ₄ and (TMTTF) ₂SCN associated with anion orderings

Y. Nogami¹ and T. Nakamura²

¹ Depattment of Physics, Okayama University, 3-1-1 Tsushimanaka, Okayama 700-8530, Japan
² Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan

Abstract
Electronic transfer integrals ( t) and TMTTF molecular ionicities (p) in several Fabre salts were estimated using the atomic coordinates obtained by systematic X-ray structure analyses at room and low temperatures. Among these Fabre salts containing the octahedal anions, (TMTTF) ₂PF ₆ has the largest degree of 4 $k_{\rm F}$ bond dimerization in t, (TMTTF) ₂AsF ₆, does the middle and (TMTTF) ₂SbF ₆ has the smallest. This tendency correspondr well to the degree of 2 $k_{\rm F}$ spin-Peierls instability at low temperatures which had been estimated. However opposite tendency was observed between the magnitude of the 4 $k_{\rm F}$ , bond dimerization and the reported critical temperature of the charge disproportionation. The charge mochlation patterns and the transfer integral modulation patterns of two salts containing non centrosymmetric anions, (TMTTF) ₂ReO ₄ and (TMlTF) ₂SCN were compared.

X-ray observation of 2 and 4 charge orderings in (TMTTF) 2Re0 4 and (TMTTF) 2SCN associated with anion orderings

X-ray observation of 2 $k_{\rm F}$ and 4 $k_{\rm F}$ charge orderings in (TMTTF) ₂Re0 ₄ and (TMTTF) ₂SCN associated with anion orderings