Evolution of the Magnetic Ground States in Mn-Intercalated 2 <i>H</i> -TaS ₂ Crystals

Because of their rich and highly tunable physical properties, TaS₂-based crystals have become a prominent platform for condensed matter research. Most previous studies of 2<i>H</i>-<i>M</i>_<i>x</i>TaS₂ have focused on intercalation concentrations of 1/4 and 1/3. However, some recent reports reveal that the nonstoichiometric compositions (deviating from the 1/4 and 1/3 ratios) could also exhibit novel physical properties. Here, the magnetic properties of 2<i>H</i>-Mn_<i>x</i>TaS₂ single crystals (0.089 ≤ <i>x</i> ≤ 0.472) are systematically investigated, where the Mn ions are intercalated into the vdW gaps of the 2<i>H</i>-TaS₂ phase. Mn intercalation induces distinct magnetic ground states: a cluster spin glass (CSG) state (<i>x</i> ≤ 0.206), an in-plane soft ferromagnetic (FM) state (0.206 ≤ <i>x</i> < 0.392) with the highest Curie temperature (<i>T</i>_C ∼ 105 K) at <i>x</i> = 0.282, and an antiferromagnetic (AFM) state (<i>x</i> ≥ 0.392). The transition between the FM and AFM states, as well as the maximum <i>T</i>_C, is attributed to the periodic oscillation of the 2D Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction caused by the variation of interlayer Mn spacing. These results provide new insights into the tunable magnetic ground states of transition-metal-intercalated 2<i>H</i>-TaS₂ systems.