Ceramics-Silikáty 49 (1) 1-6 (2005)

Water-induced and Co-filling kontrol induced ferromagnetism in Rb₂Ni₃S₄

K. Hondou, M. Usuda, K. Iio

The influence of water-immersing on the magnetic behavior of Rb₂Ni₃S₄ single crystals grown by the flux method was studied, where the intrinsic substance is non-magnetic because of the low spin state of Ni²⁺ in a Kagome lattice. The influence of Co-doping to Rb₂Ni₃S₄ was also studied in terms of the local spin density approximation (LSDA) band structure calculation. Residual ferromagnetic moments appeared in specimens immersed into water, as their magnitudes increase depending on the immersion time. The LSDA band structure calculation suggested that Co substitution for Ni allows deriving a novel ferromagnetic behavior.

Keywords: Magnetic susceptibility, Electric resistivity, Chalcogenide; (NiS₄) Square plane; Kagome lattice