Simultaneous study of the dependences of the structural parameters, electrical, and magnetic properties of hafnium disulfide intercalated iron atoms in the dependence on the intercalate concentration and temperature has been performed for the first time. The temperature dependences of the electrical resistance are shown to exhibit the activation character with the activation energies characteristic of impurity conduction. The effective magnetic moments of iron ions in Fe_ x HfS_2 is found to be significantly lesser than the values of free iron ions and to decrease as the iron content increases. The character of the temperature dependences of the effective magnetic moments and negative values of the paramagnetic Curie temperatures indicate possible interactions of the antiferromagnetic type between intercalated atoms. However, the dependences of the magnetization on field for Fe_0.33HfS_2 and Fe_0.5HfS_2 obtained at T = 2 K demonstrate the hysteresis phenomenon characteristic of the ferromagnetic state. The results are discussed assuming the existence of hybridization 3 d electron states of intercalated iron atoms with the electronic states of HfS_2 matrices and the competition of various exchange interaction.

An analysis of the nature of the change in magnetic properties in the Cr-Cu-HfSe2 system as a result of separate and joint intercalation of hafnium diselenide by chromium and copper atoms is presented. It is shown that a paramagnetic state is formed in three-component systems, which is described by the Curie–Weiss law. In CuxCr0.25HfSe2 compounds, when approximating the temperature dependences of the magnetic susceptibility, the dependence of the effective magnetic moments in magnitude and the Curie-Weiss paramagnetic temperature in magnitude and sign on the temperature range of approximation was noted. When this interval was shifted to higher temperatures, there was a monotonous decrease in the magnitude of the effective magnetic moments and a change in the sign of the paramagnetic Curie-Weiss temperature from negative to positive. To describe this dependence, it is proposed to use alternative models for the formation of the magnetic state.