Dependence of the structural, transport and magnetic properties of Tl1-yFe2-z(Se1-xSx)2 with isovalent substitution of Se by S - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Physics: Condensed Matter Année : 2013

Dependence of the structural, transport and magnetic properties of Tl1-yFe2-z(Se1-xSx)2 with isovalent substitution of Se by S

Résumé

The effect of selenium substitution by sulfur in the Tl$_{1-y}$Fe$_{2-z}$Se$_{2}$ antiferromagnet was studied by x-ray and electron diffraction, magnetization and transport measurements. Tl$_{0.8}$Fe$_{1.5}$(Se$_{1-x}$S$_{x}$)$_{2}$ (nominal composition) solid solution was synthesized in the full x range (0~$\le x(S)\le$~1) using the sealed tube technique. No superconductivity was found down to 4.2K in the series despite the fact that the optimal crystallographic parameters, determined by Rietveld refinements, are reached in the series (i.e. the Fe-(Se,S) interplane height and (Se,S)-Fe-(Se,S) angle for which the critical superconducting transition T$_{c}$ is usually maximal in pnictides). Quasi~full Tl site ($y\sim0.05$) compared to significant alkaline deficiency ($y=0.2-0.3$) in analogous A$_{1-y}$Fe$_{2-z}$Se$_{2}$ (A~=~K,~Rb,~Cs), and the resulting differences in iron valency, density of states and doping, are suggested to explain this absence of superconductivity. Transmission electron microscopy confirmed the existence of ordered iron vacancies network in the samples of the Tl$_{0.8}$Fe$_{1.5}$(Se$_{1-x}$S$_{x}$)$_{2}$ series in the form of the tetragonal $\sqrt{5}$ a $\times \sqrt{5}$ a $\times$ c superstructure (\textit{I4/m}). The N\'{e}el temperature (T$_{N}$) indicating the onset of antiferromagnetism order in this $\sqrt{5}$ a $\times \sqrt{5}$ a $\times$ c supercell is found to decrease from 450K in the selenide (x=0) to 330K in the sulfide (x=1). We finally demonstrate a direct linear relationship between $T_{N}$ and the Fe-(Se,S) bond length (or Fe-(Se,S) height).
Fichier principal
Vignette du fichier
Tl122_series_submission_JPhysCondMatt_FINAL.pdf (1.59 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-00813599 , version 1 (15-04-2013)

Identifiants

Citer

Pierre Toulemonde, David Santos-Cottin, Christophe Lepoittevin, Pierre Strobel, Jacques Marcus. Dependence of the structural, transport and magnetic properties of Tl1-yFe2-z(Se1-xSx)2 with isovalent substitution of Se by S. Journal of Physics: Condensed Matter, 2013, 25, pp.075703. ⟨10.1088/0953-8984/25/7/075703⟩. ⟨hal-00813599⟩
306 Consultations
244 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More