Dynamic cluster magnetic subsystems in diluted magnetic semiconductor Ge1– <i>x</i> – <i>y</i> Sn <i>x</i> Mn <i>y</i> Te

The present work is devoted mainly to the study of the magnetic properties of a diluted magnetic semiconductor Ge1–x–ySnxMnyTe. Analysis of the temperature dependencies of the real part of the dynamic magnetic susceptibility Re(χac) revealed a characteristic “two-hump” shape of the curves, which indicates the existence of at least two disordered magnetic subsystems: a spin glass (left peak with a Mydosh parameter R ≈ 0) and a spin-glass-like phase (right peak with R = 0.017). The shape of the Re(χac) curves and the dynamics of their form with changes in the frequency of the external magnetic field Hac cannot be explained within the framework of existing notions about the static nature of magnetic clusters. In this work, a fundamentally new approach is proposed and substantiated, according to which the shape of the experimental Re(χac) curves is a superposition of Gaussian curves, corresponding to four types of magnetic subsystems formed by dynamic magnetic clusters with different spatial dimensions: 0D, 1D, 2D, and 3D. At temperatures T &amp;gt; 0 K, these clusters are dynamic formations similar to standing waves, the dimensionality of which increases from 0D to 3D with increasing temperature and the amplitude of thermal vibrations of the crystal lattice. Within the framework of the proposed model, the concept of the spin freezing temperature TF is clarified, which indicates the beginning, not the completion, of this process. The concepts of critical temperatures (TK, β) are introduced, which are symmetric with respect to TF analogs of the Curie (TC) and Curie–Weiss (Θ) temperatures. The concept of integral dynamic magnetic susceptibility is introduced, which allows for the quantitative evaluation of the dynamics of cluster magnetic subsystems under the influence of external and internal factors. The correctness of the proposed model is confirmed by analyzing the Re(χac)(T) dependencies in layered crystals. In InSe crystals intercalated with cobalt, the number of magnetic subsystems decreases to three (0D–2D) compared to the four subsystems (0D–3D) in Mn-doped InSe. We attribute this to the constraints that the layered crystal structure of InSe imposes on the maximum possible (2D) dimensionality of the Mn magnetic clusters in the interlayer space of InSe.