Emergent superparamagnetism and anomalous Hall effect in two-dimensional magnet CrxPt1-xTe2

Reducing magnetic domain size to the nanoscale can generate unconventional with short-range magnetic phases, such as spin-glass states, Griffiths phase, and superparamagnetism. Here, we report the synthesis of a two-dimensional magnet, CrxPt1−xTe2, using the self-flux method. Magnetization and anomalous Hall effect (AHE) measurements reveal a canonical temperature-dependent evolution from a blocked superparamagnetic state at low temperature to a superparamagnetic state at intermediate temperature and a paramagnetic state at high temperature. Scanning transmission electron microscopy with magnetization analyses based on the Langevin function demonstrates that the superparamagnetism arises from the formation of magnetic nanoclusters induced by Cr doping within the PtTe2 lattice. Importantly, the AHE cannot be well described by conventional scaling laws developed for long-range ordered magnetic systems. This motivates a phenomenological framework based on multiple competing scattering mechanisms, where the blocking dynamics of magnetic nanoclusters governs the AHE. These findings enhance our understanding of superparamagnetism in CrxPt1−xTe2 and motivate the development of theoretical models for short-range ordered magnetism. Reducing magnetic domain size to the nanoscale can lead to unconventional short-range magnetic phases. Here, the authors synthesize a two-dimensional magnet, CrxPt1-xTe2, revealing a temperature-dependent evolution of superparamagnetism and a unique anomalous Hall effect, advancing our understanding of short-range ordered magnetism and inspiring new theoretical models.