Spin-density-wave transition of Fe1 zigzag chains and metamagnetic transition of Fe2 in TaFe1+yTe3

Abstract

The mixed-metal-network layered compound TaFe${}_{1+x}$Te${}_{3}$ has the TaFeTe${}_{3}$ layers formed by Ta-Fe bonded network (Fe1) sandwiched with tellurium layers and the excess iron atoms (Fe2) partially occupying the interstitial site of the tetrahedral (Ta,Fe)Te at random, which are similar to the interstitial iron atoms in the iron-based high-${T}_{c}$ superconductor Fe${}_{1+y}$Te. The antiferromagnetic (AFM) transition of Fe1 zigzag chains and spin flop of these interstitial Fe2 atoms under a high magnetic field are studied through susceptibility, magnetoresistance (MR), the Hall effect, and specific heat measurements in high-quality single-crystal TaFe${}_{1+y}$Te${}_{3}$. These properties suggest that the high-temperature AFM transition of the TaFeTe${}_{3}$ layers should be a spin-density-wave-type AFM order. Below ${T}_{N}$, the spin flop of these interstitial Fe2 from antiferromagnetism to ferromagnetism induces a sharp drop on resistivity and an anomalous Hall effect. It can be inferred from the spin flop of Fe2 that the local moment of Fe2 atom is about 4 ${\ensuremath{\mu}}_{B}$/Fe. The possible magnetic structure of TaFe${}_{1+y}$Te${}_{3}$ is proposed from the susceptibility, MR, and Hall effect. The properties related to the spin flop of Fe2 supply a good opportunity to study the coupling between Fe1 and Fe2 in these TaFe${}_{1+y}$Te${}_{3}$ or Fe${}_{1+y}$Te compounds with interstitial Fe2.