A neutron and Mössbauer study of TlFexS2 compounds

Structure, magnetic order and excitations in the 245 family of Fe-based superconductors

“…The latter suggests Fe vacancy in the FeSe plane since two different kinds of Fe vacancy orders have been reported previously in chalcogenide TlFe 2−x S 2 and TlFe 2−x P 2 [18,19].…”

Microstructure and ordering of iron vacancies in the superconductor systemKyFexSeWang1, Song2, Shi3 et al. 2011Phys. Rev. B

“…1 in correlation with the Fe-deficiency in present superconducting system. According to previous neutron diffraction study for TlFe x Se 2 (1.5<x<2) [12] and careful analysis of our TEM data, we herein interpret this superstructure phase by a Fe-vacancy order along the It is also noted that the superstructure with lattice parameter 2´2 d 110 as discussed for KFe 1.5 Se 2 in previous literature [20] appears frequently in certain areas. Fig.…”

“…Measurements of optical properties of K0.8FexSe2 demonstrate that the superconductivity is in close proximity to an antiferromagnetic semiconducting phase [11]. In KFe x Se 2 , the potassium sheets are intercalated between the FeSe layers stacking along c-axis direction, as discussed for TlFe x S 2 and TlFe x Se 2 [12,13] [14][15][16]. In order to understand the microstructure features in correlation with the Fe-deficiency in present system, we performed an extensive structural investigation by means of selected-area electron diffraction and high-resolution TEM observations.…”

Ternary iron selenideK0.8Fe1.6SeYan1, Gao2, Lu3 et al. 2011Phys. Rev. B

“…In an Fe-Fe square lattice, an Fe atom nearby a vacancy is 3-Fe-neighbored, or 2-Fe-neighbored, or even 1-Fe-neighbored. Topologically a square lattice composed only by 3-Fe-neighbored Fe atoms exists only in one arranging order but with two different kinds of chirality, right-handed or left-handed rotations [15], as shown in Fig. 1(b) and (c), respectively.…”