Spin-glass behavior in Shastry-Sutherland lattice of Tm2Cu2In

The spin-glass behavior in the ferromagnetic phase of Tm2Cu2In was investigated by dc-, ac-magnetization, and non-equilibrium dynamics characterizations. An argon arc-melted polycrystalline sample of the compound of Tm2Cu2In was found to adopt the Mo2FeB2-type tetragonal structure (space group P-4/mbm). The temperature variation of dc-magnetization exhibits a ferromagnetic behavior with Curie temperature T-C = 32.5 K. The zero field cooled (ZFC) and field cooled (FC) magnetic curves show the thermomagnetic irreversible behavior below T-C. The field dependence of irreversible temperature follows the Almeida-Thouless line. The frequency and ac-driven field dependent anomalies in ac-susceptibility results indicate the existence of a spin-glass state in Tm2Cu2In. The time dependence of magnetization further supports the spin-glass behavior observed in Tm2Cu2In. The frequency dependence of the freezing temperature in the real part of ac-susceptibility has been analyzed on the basis of a power-law divergence and Vogel-Fulcher law. The obtained results reveal that Tm2Cu2In belongs to the ferromagnetic canonical spin-glass class of compounds.