Random spin freezing in single crystalline Ce₂CuSi₃

We present the results of ac and dc susceptibility, magnetization and magnetic relaxation measurements performed on single crystalline Ce ₂CuSi₃, a hexagonal AlB₂-type nonmagnetic atom disorder compound, with the magnetic field applied along two typical crystallographic directions, i.e. H⊥c-axis and H//c-axis. For both the directions, spin-glass state is confirmed to form at low temperature with almost the same spin freezing temperature T_f (∼2.07K), initial frequency shift δT_f (∼0.015) and activation energy E _a/k_B (∼10.04 K) in zero dc field. Strong magnetic anisotropy is also found to be a significant feature of this compound. The experimental results and the dynamical analyses suggest that spin-glass behavior is intrinsic to the title compound.