Investigation of the Magnetic Properties of Ni0.7Fe0.3Ga2S4

다국어 초록 (Multilingual Abstract)

We have studied the magnetic properties of Ni0.7Fe0.3Ga2S4 with Fe substituted at the Ni sites by using an X-ray diffractometer (XRD), a superconducting quantum interference device (SQUID)magnetometer, and a M¨ossbauer spectrometer. The polycrystalline sample of Ni0.7Fe0.3Ga2S4 is found to be a single phase of the trigonal structure with a space group of P-3m1. The structural parameters of the sample are obtained by using a Reitveld refinement with lattice constants of a0 = 3.640 °A and c0 = 12.020 °A. The bond length between Fe and S ions is about 2.420 °A,which suggests a short-range ordering with the frustration effect. From the M¨ossbauer spectra, the magnetic hyperfine field and the electric quadrupole interaction are estimated to be Hhf = 124.2kOe, and EQ = 2.10 mm/s, respectively, at 4.2 K. The charge state of the Fe ions is ferrous (Fe2+) from the value of the isomer shift, δ = 0.66 mm/s, at room temperature. The spin quantum number of Ni0.7Fe0.3Ga2S4 is determined to be S = 3/2, while it is S = 1 for NiGa2S4 and S = 2for FeGa2S4. This indicates an increase an spin-orbital interactions with increasing Fe.

참고문헌 (Reference)

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