Magnetic properties of the Fe-intercalated misfit-layer compounds(RS)x[Fe0.33(NbS2)2](R=La,Ce)

Abstract

We synthesized the Fe intercalated misfit-layer compounds $(R\mathrm{S}{)}_{x}[{\mathrm{Fe}}_{0.33}({\mathrm{NbS}}_{2}{)}_{2}]$ $(R=\mathrm{L}\mathrm{a},\mathrm{C}\mathrm{e}),$ and investigated their magnetic properties. The intercalated Fe atoms form the $\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3}$ superlattice to the ${\mathrm{NbS}}_{2}$ lattice in these compounds, and show the successive magnetic transition at 15 and 22 K. The strong frustration appears between two transition temperatures in their quasi-two-dimensional antiferromagnetic triangular Ising spin system. The temperature dependence of the susceptibility of $(\mathrm{CeS}{)}_{1.16}[{\mathrm{Fe}}_{0.33}({\mathrm{NbS}}_{2}{)}_{2}]$ shows three magnetic transitions at 3.4, 15, and 22 K corresponding to the antiferromagnetic transition of Ce and Fe. This suggests that the magnetic interactions of Ce and Fe occur independently.