Structural characteristics and magnetic properties of cobalt-intercalated A$_2^5$B$_3^6$ single crystals

The magnetic properties of the Bi$_2$Te$_3$ and Bi$_2$Se$_3$ single crystals intercalated by cobalt in a dc magnetic field are considered. The effect of a dc magnetic field on the introduction and the magnetic properties of the formed intercalates is studied. It is shown that the introduction of cobalt into Bi$_2$Te$_3$ (Bi$_2$Se$_3$) is accompanied by a change in the lattice parameters depending on the presence of a magnetic field during intercalation and that the structure type of the crystals remains unchanged. Co$_{0.15}$Bi$_2$Te$_3$ and Co$_{0.15}$Bi$_2$Se$_3$ intercalates exhibit ferromagnetism: the magnetic-field dependence of the magnetic moment has the shape of hysteresis loops typical of hard magnetic ferromagnets.