Half Antiperovskites VI: On the Substitution Effects in Shandites In_xSn_2–xCo₃S₂

Abstract

In the shandite type solid solution InxSn2–xCo3S2 the transition from half metal ferromagnetic Sn2Co3S2 to the new thermoelectric InSnCo3S2 is related to A = In, Sn on different crystallographic sites. Effects and origin of crystal and electronic structure changes induced by A = In are now investigated within the solid solution 0 ≤ x ≤ 2 including In2Co3S2. Effects are studied from X‐ray data, 119Sn Mößbauer spectroscopy, and ab initio calculations. Their origin is explored by DFT modeling on site preference of In and Sn in a supercell, electric field gradients (EFG), spin polarization, band structures, and direct space analyses (ELF, AIM). Indium is found to cause the crystal structure distortion on one A site, the electronic structure distortion to the other, as a consequence of inverted anisotropic bonding.

Single crystal growth and characterization of kagomé-lattice shandites Co3Sn2−In S2

“…c Increases monotonically with x, whereas a shows a linear decrease until x$ 0.8 and almost remains constant for a higher In concentration region. Our results are in good agreement with previously reported results using polycrystalline samples [10,12,19], if considering of the reduction of the actual In concentration from the nominal ones in the grown single crystals (Section 3.1). In the polycrystalline samples, the change of the concentration dependence of a was found around x¼1.…”

“…5 shows the ratio of c to a against x, indicating an enhancement of the trigonal distortion by the In-substitution. The trigonal distortion enhanced by the In-substitution was explained by the different bonding-contributions of Sn-and In-5p states based on the ab initio calculations [19]. The slope of the increase of c/a apparently changes around x$0.8 as well as the concentration dependence of a.…”

“…Theoretical band-structure calculations and photoemission study indicated a half metalicity of the ferromagnetic state of Co 3 Sn 2 S 2 [9,15,17] which is classified as a type I A half-metallic ferromagnet [18]. The counterpart Co 3 In 2 S 2 was predicted as a paramagnetic metal by recent theoretical band calculations [19], which implies the ferromagnetic quantum phase transition by the In-substitution for Sn in Co 3 Sn 2 À x In x S 2 series. Indeed, suppression of the ferromagnetism of Co 3 Sn 2 S 2 by the Insubstitution for Sn was reported for polycrystalline samples [10,14].…”

Designing 3D topological insulators by 2D-Xene (X = Ge, Sn) sheet functionalization in GaGeTe-type structures

“…The total energy was converged on a k-mesh with 10 Â 10 Â 10 k-points. Besides adjusted all-electron basis sets for Ga (86-4111d41G), 59 Ge (97-631d61G), 60 In (97-63111d631G) [61][62][63] and Sn (97-63111d631G), 64 an all-electron basis set for Te 65 and a pseudopotential basis set (m-pVDZ-PP) for a scalar-relativistic description of Te 66 were used.…”

Quasi-Two-Dimensional Magnetism in Co-Based Shandites

“…for the half metallic ferromagnetism were predicted. 21,25,[30][31][32] Indeed, semiconducting or semimetallic transport properties of the Co 3 SnInS 2 polycrystals and the ferromagnetic instability in the In-substituted Co 3 Sn 2 S 2 were reported. 21,23,25,26,33) The suppressions of the ferromagnetic order by the Ni-and Fesubstitution for Co were also observed, [34][35][36] while the Sesubstitution for S causes slight reduction of T C .…”