%0 Journal Article
%A Medyanik, Katerina
%A de Souza, Mariano
%A Kutnyakhov, Dmytro
%A Gloskovskii, Andrei
%A Müller, Jens
%A Lang, Michael
%A Pouget, Jean-Paul
%A Foury-Leylekian, Pascale
%A Moradpour, Alec
%A Elmers, Hans-Joachim
%A Schönhense, Gerd
%T Hard X-ray photoemission study of the Fabre salts (TMTTF)<sub>2</sub>X (X = SbF<sub>6</sub> and PF<sub>6</sub>)
%J The European physical journal / B
%V 87
%N 11
%@ 1434-6028
%C Berlin
%I Springer
%M PUBDB-2015-00173
%P 256
%D 2014
%Z (c) EDP Sciences, Societa Italiana di Fisica, Springer-Verlag. Post referee fulltext in progress. Embargo ab 03 Nov 2014.
%X Core-level photoemission spectra of the Fabre salts with X = SbF6 and PF6 were taken using hard X-rays from PETRA III, Hamburg. In these salts TMTTF layers show a significant stack dimerization with a charge transfer of 1e per dimer to the anion SbF6 or PF6 . At room temperature and slightly below the core-level spectra exhibit single lines, characteristic for a well-screened metallic state. At reduced temperatures progressive charge localization sets in, followed by a 2nd order phase transition into a charge-ordered ground state. In both salts groups of new core-level signals occur, shifted towards lower kinetic energies. This is indicative of a reduced transverse-conductivity across the anion layers, visible as layer-dependent charge depletion for both samples. The surface potential was traced via shifts of core-level signals of an adsorbate. A well-defined potential could be established by a conducting cap layer of 5 nm aluminum which appears “transparent” due to the large probing depth of HAXPES (8–10 nm). At the transition into the charge-ordered phase the fluorine 1s line of (TMTTF)2 SbF6 shifts by 2.8 eV to higher binding energy. This is a spectroscopic fingerprint of the loss of inversion symmetry accompanied by a cooperative shift of the SbF6 anions towards the more positively charged TMTTF donors. This shift does not occur for the X = PF6 compound, most likely due to smaller charge disproportion or due to thepresence of charge disorder.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000344645900001
%R 10.1140/epjb/e2014-50499-y
%U https://bib-pubdb1.desy.de/record/205613