Synthesis, structure, and magnetic properties of anion-substituted manganese chalcogenides

The anion-substituted solid solutions of the MnSe$_{1-x}$Te$_x$ system have been synthesized. The crystal structure and magnetic properties of the synthesized solid solutions have been investigated. It has been shown that, in the concentration range 0 $\le x\le$ 0.4, the solid solutions have a face-centered cubic structure. It has been revealed that an increase in the concentration of the substituting element in the MnSe$_{1-x}$Te$_x$ system leads to an increase in the coefficient of thermal expansion of the sample. The investigation of the magnetic properties has been carried out at temperatures in the range 80 K $< T <$ 1000 K in a magnetic field up to 8.6 kOe. It has been experimentally found that the type of antiferromagnetic order (the second type of ordering) remains unchanged over the entire concentration range up to $x$ = 0.4 and that the paramagnetic Curie temperature and the Néel temperature decrease within the limits of 20%. Theoretical calculations have been performed using the Monte Carlo method, and the model of nanoclusters with an uncompensated antiferromagnetic moment has been proposed.