Effects of stoichiometry and substitution in quasi-one-dimensional iron chalcogenideBaFe2S3

Abstract

The effects of off-stoichiometry and elemental substitution on electronic properties of iron-based ladder compound BaFe2S3 are investigated. Resistivity and magnetization are revealed to be quite sensitive to the stoichiometry of Fe atoms, and 10 % deficiency at Fe sites reduces the antiferromagnetic transition temperature by 40 K. The antiferromagnetic transition temperature decreases even faster and collapse to zero with hole doping through 10 % K substitution at Ba site, while the antiferromagnetic ordering phase remains with electron doping through 20 % Co substitution at Fe site. Such electron-hole asymmetry is opposite to two-dimensional iron-based superconductors, and can be explained on the basis of both itinerant and localized electronic pictures.

Magnetic Precursor of the Pressure-Induced Superconductivity in Fe-Ladder Compounds

“…(iii) The maximum value of T N at the pressure-induced QPT is also characteristic of Mott critical coupling under the influence of strong Hund's rule coupling [35,36]. (iv) An unknown transition at about 200 K [7,18] tends to decrease and merge with T N as pressure increases [7,20]. This transition is possibly related to orbital ordering and hints of the critical role of the orbitals in forming the magnetic ground state in BaFe 2 S 3 .…”

“…3(f)]. The order parameter on cooling shows no hysteresis, suggesting the glassy behavior in Ba 1−x Cs x Fe 2 Se 3 [17] and Ba 1−x K x Fe 2 S 3 [18] is likely caused by the change of carrier concentrations. Fig.…”

“…This is certainly not the case for BaFe 2 S 3 . In an itinerant picture, on the other hand, the pressure can potentially modify the Fermi pockets [21] to improve the nesting feature, but neither hole-nor electron-doping produces such drastic magnetic enhancement [18,27]. If the pressure indeed reduces correlation, by increasing the bandwidth and decreasing U [21], and subsequently delocalizes Fe 3d electrons, the increased hopping on the ladder rungs, through some double exchange mechanism, should be able to enhance the FM interactions.…”

Bandwidth controlled insulator-metal transition in BaFe2S3 : A Mössbauer study under pressure

“…Yamauchi et al conducted dc resistivity measurements and observed a maximum in T N at ∼ 3 GPa followed by a monotonic reduction with increasing pressure [6]. Reasons for the discrepancy could be anisotropies in the resistivity or slightly different stochiometries [25]. The increase of T N between 0 and 7.5 GPa can be explained by an increase of the exchange interaction [14].…”

Gradual enhancement of stripe-type antiferromagnetism in the spin-ladder material BaFe2S3 under pressure

“…In both systems, the FeX 4 edge-sharing tetrahedra create well-separated iron ladders [11], distinct from the planar square lattice of other FeSCs. These compounds therefore represent an important new family of materials that has attracted significant theoretical and experimental attention in the quest to understand iron-based superconductivity [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. BaFe 2 S 3 belongs to the orthorhombic space group Cmcm and orders antiferromagnetically below ∼100-120 K in a stripe-type spin configuration [8].…”