- Conference date: 3-6 December 1974
- Location: San Francisco, CA, USA
Magnetic susceptibility, electrical resistivity and Mössbauer effect (ME) measurements in single crystals of the metal intercalation layer compound FexTaS2 are reported. Crystals are grown by iodine vapor transport from Fe1/3TaS2 powder. The crystals contain less Fe than the powder with x? .28. The resistivity (ρ) shows a metallic behavior, ρ=2.7×10− 5 ohm−cm at 300°K. Magnetization curves as a function of temperature, obtained cooling the sample in H=10 kG, revealed that the compound is a ferromagnet with a Curie temperature (Tc) of (85±3) °K. Above Tc the susceptibility obeys a Curie Weiss law with μ∥ 3ff=μeff ⊥=4.5−0.1 μ B and ϑ⊥=30−2°K and τ∥=90−3°K. Above Tc, μeff and Pgt are very similar for powder (x=1/3) and single crystal (x?0.28) samples. At 4.2°K the magnetic moment is 3.5 μ B per Fe and is parallel to the hexagonal c axix. A large coercive force of 50 kG is required to reverse the spins. A field of 60 kG is not enough to saturate the moment at low temperatures. In the paramagnetic state the 57E ME spectra show two resonance lines due to quadrupole splitting; e2qQ/2=0.64±0.03 mm/sec at room temperature. The isomer shift with respect to iron metal is 0.83±0.03 mm/sec at 300°K, and indicates that the iron atoms are in the Fe2 + atoms contrary to previous structure determinations (from powder diffraction data) where only one ordered Fe site (octahedral) was proposed. At 4.2°K the average hyperfine field is Hh f=185 Kg and e2qQ/2=0.85 mm/sec. In light of the high coercive force, the high magnetic moment and the complexity of the Mössbauer spectrum (at 4.2°K), it appears that even in single crystals two‐dimensional Fe clusters occur. These observations may explain the diversity of magnetic properties reported for the same 3d intercalation compounds of either 2H−NbS2 or 2H−TaS2.
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